support unconvert

Gopkg.lock

@@ -120,6 +120,12 @@
   packages = ["."]
   revision = "b1d89398deca2fd3f8578e5a9551e819bd01ca5f"
 
+[[projects]]
+  branch = "master"
+  name = "github.com/golangci/unconvert"
+  packages = ["."]
+  revision = "28b1c447d1f4a810737ee6ab40ea6c1d0ceae4ad"
+
 [[projects]]
   name = "github.com/inconshreveable/mousetrap"
   packages = ["."]
@@ -237,6 +243,19 @@
   ]
   revision = "6f686a352de66814cdd080d970febae7767857a3"
 
+[[projects]]
+  name = "golang.org/x/text"
+  packages = [
+    "internal/gen",
+    "internal/triegen",
+    "internal/ucd",
+    "transform",
+    "unicode/cldr",
+    "width"
+  ]
+  revision = "f21a4dfb5e38f5895301dc265a8def02365cc3d0"
+  version = "v0.3.0"
+
 [[projects]]
   branch = "master"
   name = "golang.org/x/tools"
@@ -281,6 +300,6 @@
 [solve-meta]
   analyzer-name = "dep"
   analyzer-version = 1
-  inputs-digest = "6e4437a7adb255525e8d1cfda07716617c1f28acaa721ac4f910f52f49ecea2f"
+  inputs-digest = "3c773b17692c1bc6ce7d565b959908aa95160e5d4f2486721deaff48608c864e"
   solver-name = "gps-cdcl"
   solver-version = 1

pkg/enabled_linters.go

@@ -70,6 +70,7 @@ func GetAllSupportedLinterConfigs() []LinterConfig {
 		enabledByDefault(golinters.Dupl{}, "Tool for code clone detection", false, false),
 		enabledByDefault(golinters.Ineffassign{}, "Detects when assignments to existing variables are not used", false, false),
 		enabledByDefault(golinters.Interfacer{}, "Linter that suggests narrower interface types", true, true),
+		enabledByDefault(golinters.Unconvert{}, "Remove unnecessary type conversions", true, false),
 
 		disabledByDefault(golinters.Gofmt{}, "Gofmt checks whether code was gofmt-ed. By default this tool runs with -s option to check for code simplification", false, false),
 		disabledByDefault(golinters.Gofmt{UseGoimports: true}, "Goimports does everything that gofmt does. Additionally it checks unused imports", false, false),

pkg/golinters/testdata/govet.go

@@ -1,14 +1,17 @@
 package testdata
 
-import "os"
+import (
+	"io"
+	"os"
+)
 
 func Govet() error {
 	return &os.PathError{"first", "path", os.ErrNotExist} // ERROR "os.PathError composite literal uses unkeyed fields"
 }
 
-func GovetShadow(f *os.File, buf []byte) (err error) {
+func GovetShadow(f io.Reader, buf []byte) (err error) {
 	if f != nil {
-		_, err := f.Read(buf) // ERROR "declaration of .err. shadows declaration at testdata/govet.go:9"
+		_, err := f.Read(buf) // ERROR "declaration of .err. shadows declaration at testdata/govet.go:\d+"
 		if err != nil {
 			return err
 		}

pkg/golinters/testdata/interfacer.go

@@ -2,6 +2,6 @@ package testdata
 
 import "io"
 
-func InterfacerCheck(f io.ReadCloser) { // ERROR "XXX"
+func InterfacerCheck(f io.ReadCloser) { // ERROR "f can be io.Closer"
 	f.Close()
 }

pkg/golinters/testdata/unconvert.go

@@ -0,0 +1,9 @@
+package testdata
+
+import "log"
+
+func Unconvert() {
+	a := 1
+	b := int(a) // ERROR "unnecessary conversion"
+	log.Print(b)
+}

pkg/golinters/unconvert.go

@@ -0,0 +1,29 @@
+package golinters
+
+import (
+	"context"
+
+	"github.com/golangci/golangci-lint/pkg/result"
+	unconvertAPI "github.com/golangci/unconvert"
+)
+
+type Unconvert struct{}
+
+func (Unconvert) Name() string {
+	return "unconvert"
+}
+
+func (lint Unconvert) Run(ctx context.Context, lintCtx *Context) (*result.Result, error) {
+	positions := unconvertAPI.Run(lintCtx.Program)
+	res := &result.Result{}
+	for _, pos := range positions {
+		res.Issues = append(res.Issues, result.Issue{
+			File:       pos.Filename,
+			LineNumber: pos.Line,
+			Text:       "unnecessary conversion",
+			FromLinter: lint.Name(),
+		})
+	}
+
+	return res, nil
+}

vendor/github.com/golangci/unconvert/LICENSE

@@ -0,0 +1,27 @@
+Copyright (c) 2012 The Go Authors. All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are
+met:
+
+   * Redistributions of source code must retain the above copyright
+notice, this list of conditions and the following disclaimer.
+   * Redistributions in binary form must reproduce the above
+copyright notice, this list of conditions and the following disclaimer
+in the documentation and/or other materials provided with the
+distribution.
+   * Neither the name of Google Inc. nor the names of its
+contributors may be used to endorse or promote products derived from
+this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

vendor/github.com/golangci/unconvert/README

@@ -0,0 +1,36 @@
+About:
+
+The unconvert program analyzes Go packages to identify unnecessary
+type conversions; i.e., expressions T(x) where x already has type T.
+
+Install:
+
+    $ go get github.com/mdempsky/unconvert
+
+Usage:
+
+    $ unconvert -v bytes fmt
+    GOROOT/src/bytes/reader.go:117:14: unnecessary conversion
+                    abs = int64(r.i) + offset
+                               ^
+    GOROOT/src/fmt/print.go:411:21: unnecessary conversion
+            p.fmt.integer(int64(v), 16, unsigned, udigits)
+                               ^
+
+Flags:
+
+Using the -v flag, unconvert will also print the source line and a
+caret to indicate the unnecessary conversion's position therein.
+
+Using the -apply flag, unconvert will rewrite the Go source files
+without the unnecessary type conversions.
+
+Using the -all flag, unconvert will analyze the Go packages under all
+possible GOOS/GOARCH combinations, and only identify conversions that
+are unnecessary in all cases.
+
+E.g., syscall.Timespec's Sec and Nsec fields are int64 under
+linux/amd64 but int32 under linux/386.  An int64(ts.Sec) conversion
+that appears in a linux/amd64-only file will be identified as
+unnecessary, but it will be preserved if it occurs in a file that's
+compiled for both linux/amd64 and linux/386.

vendor/github.com/golangci/unconvert/unconvert.go

@@ -0,0 +1,665 @@
+// Copyright 2015 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Unconvert removes redundant type conversions from Go packages.
+package unconvert
+
+import (
+	"bytes"
+	"flag"
+	"fmt"
+	"go/ast"
+	"go/build"
+	"go/format"
+	"go/parser"
+	"go/token"
+	"go/types"
+	"io/ioutil"
+	"log"
+	"os"
+	"reflect"
+	"runtime/pprof"
+	"sort"
+	"sync"
+	"unicode"
+
+	"github.com/kisielk/gotool"
+	"golang.org/x/text/width"
+	"golang.org/x/tools/go/loader"
+)
+
+// Unnecessary conversions are identified by the position
+// of their left parenthesis within a source file.
+
+type editSet map[token.Position]struct{}
+
+type fileToEditSet map[string]editSet
+
+func apply(file string, edits editSet) {
+	if len(edits) == 0 {
+		return
+	}
+
+	fset := token.NewFileSet()
+	f, err := parser.ParseFile(fset, file, nil, parser.ParseComments)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	// Note: We modify edits during the walk.
+	v := editor{edits: edits, file: fset.File(f.Package)}
+	ast.Walk(&v, f)
+	if len(edits) != 0 {
+		log.Printf("%s: missing edits %s", file, edits)
+	}
+
+	// TODO(mdempsky): Write to temporary file and rename.
+	var buf bytes.Buffer
+	err = format.Node(&buf, fset, f)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	err = ioutil.WriteFile(file, buf.Bytes(), 0)
+	if err != nil {
+		log.Fatal(err)
+	}
+}
+
+type editor struct {
+	edits editSet
+	file  *token.File
+}
+
+func (e *editor) Visit(n ast.Node) ast.Visitor {
+	if n == nil {
+		return nil
+	}
+	v := reflect.ValueOf(n).Elem()
+	for i, n := 0, v.NumField(); i < n; i++ {
+		switch f := v.Field(i).Addr().Interface().(type) {
+		case *ast.Expr:
+			e.rewrite(f)
+		case *[]ast.Expr:
+			for i := range *f {
+				e.rewrite(&(*f)[i])
+			}
+		}
+	}
+	return e
+}
+
+func (e *editor) rewrite(f *ast.Expr) {
+	call, ok := (*f).(*ast.CallExpr)
+	if !ok {
+		return
+	}
+
+	pos := e.file.Position(call.Lparen)
+	if _, ok := e.edits[pos]; !ok {
+		return
+	}
+	*f = call.Args[0]
+	delete(e.edits, pos)
+}
+
+var (
+	cr = []byte{'\r'}
+	nl = []byte{'\n'}
+)
+
+func print(conversions []token.Position) {
+	var file string
+	var lines [][]byte
+
+	for _, pos := range conversions {
+		fmt.Printf("%s:%d:%d: unnecessary conversion\n", pos.Filename, pos.Line, pos.Column)
+		if *flagV {
+			if pos.Filename != file {
+				buf, err := ioutil.ReadFile(pos.Filename)
+				if err != nil {
+					log.Fatal(err)
+				}
+				file = pos.Filename
+				lines = bytes.Split(buf, nl)
+			}
+
+			line := bytes.TrimSuffix(lines[pos.Line-1], cr)
+			fmt.Printf("%s\n", line)
+
+			// For files processed by cgo, Column is the
+			// column location after cgo processing, which
+			// may be different than the source column
+			// that we want here. In lieu of a better
+			// heuristic for detecting this case, at least
+			// avoid panicking if column is out of bounds.
+			if pos.Column <= len(line) {
+				fmt.Printf("%s^\n", rub(line[:pos.Column-1]))
+			}
+		}
+	}
+}
+
+// Rub returns a copy of buf with all non-whitespace characters replaced
+// by spaces (like rubbing them out with white out).
+func rub(buf []byte) []byte {
+	// TODO(mdempsky): Handle combining characters?
+	var res bytes.Buffer
+	for _, r := range string(buf) {
+		if unicode.IsSpace(r) {
+			res.WriteRune(r)
+			continue
+		}
+		switch width.LookupRune(r).Kind() {
+		case width.EastAsianWide, width.EastAsianFullwidth:
+			res.WriteString("  ")
+		default:
+			res.WriteByte(' ')
+		}
+	}
+	return res.Bytes()
+}
+
+var (
+	flagAll        = flag.Bool("unconvert.all", false, "type check all GOOS and GOARCH combinations")
+	flagApply      = flag.Bool("unconvert.apply", false, "apply edits to source files")
+	flagCPUProfile = flag.String("unconvert.cpuprofile", "", "write CPU profile to file")
+	// TODO(mdempsky): Better description and maybe flag name.
+	flagSafe = flag.Bool("unconvert.safe", false, "be more conservative (experimental)")
+	flagV    = flag.Bool("unconvert.v", false, "verbose output")
+)
+
+func usage() {
+	fmt.Fprintf(os.Stderr, "usage: unconvert [flags] [package ...]\n")
+	flag.PrintDefaults()
+}
+
+func nomain() {
+	flag.Usage = usage
+	flag.Parse()
+
+	if *flagCPUProfile != "" {
+		f, err := os.Create(*flagCPUProfile)
+		if err != nil {
+			log.Fatal(err)
+		}
+		pprof.StartCPUProfile(f)
+		defer pprof.StopCPUProfile()
+	}
+
+	importPaths := gotool.ImportPaths(flag.Args())
+	if len(importPaths) == 0 {
+		return
+	}
+
+	var m fileToEditSet
+	if *flagAll {
+		m = mergeEdits(importPaths)
+	} else {
+		m = computeEdits(importPaths, build.Default.GOOS, build.Default.GOARCH, build.Default.CgoEnabled)
+	}
+
+	if *flagApply {
+		var wg sync.WaitGroup
+		for f, e := range m {
+			wg.Add(1)
+			f, e := f, e
+			go func() {
+				defer wg.Done()
+				apply(f, e)
+			}()
+		}
+		wg.Wait()
+	} else {
+		var conversions []token.Position
+		for _, positions := range m {
+			for pos := range positions {
+				conversions = append(conversions, pos)
+			}
+		}
+		sort.Sort(byPosition(conversions))
+		print(conversions)
+		if len(conversions) > 0 {
+			os.Exit(1)
+		}
+	}
+}
+
+func Run(prog *loader.Program) []token.Position {
+	m := computeEditsFromProg(prog)
+	var conversions []token.Position
+	for _, positions := range m {
+		for pos := range positions {
+			conversions = append(conversions, pos)
+		}
+	}
+	return conversions
+}
+
+var plats = [...]struct {
+	goos, goarch string
+}{
+	// TODO(mdempsky): buildall.bash also builds linux-386-387 and linux-arm-arm5.
+	{"android", "386"},
+	{"android", "amd64"},
+	{"android", "arm"},
+	{"android", "arm64"},
+	{"darwin", "386"},
+	{"darwin", "amd64"},
+	{"darwin", "arm"},
+	{"darwin", "arm64"},
+	{"dragonfly", "amd64"},
+	{"freebsd", "386"},
+	{"freebsd", "amd64"},
+	{"freebsd", "arm"},
+	{"linux", "386"},
+	{"linux", "amd64"},
+	{"linux", "arm"},
+	{"linux", "arm64"},
+	{"linux", "mips64"},
+	{"linux", "mips64le"},
+	{"linux", "ppc64"},
+	{"linux", "ppc64le"},
+	{"linux", "s390x"},
+	{"nacl", "386"},
+	{"nacl", "amd64p32"},
+	{"nacl", "arm"},
+	{"netbsd", "386"},
+	{"netbsd", "amd64"},
+	{"netbsd", "arm"},
+	{"openbsd", "386"},
+	{"openbsd", "amd64"},
+	{"openbsd", "arm"},
+	{"plan9", "386"},
+	{"plan9", "amd64"},
+	{"plan9", "arm"},
+	{"solaris", "amd64"},
+	{"windows", "386"},
+	{"windows", "amd64"},
+}
+
+func mergeEdits(importPaths []string) fileToEditSet {
+	m := make(fileToEditSet)
+	for _, plat := range plats {
+		for f, e := range computeEdits(importPaths, plat.goos, plat.goarch, false) {
+			if e0, ok := m[f]; ok {
+				for k := range e0 {
+					if _, ok := e[k]; !ok {
+						delete(e0, k)
+					}
+				}
+			} else {
+				m[f] = e
+			}
+		}
+	}
+	return m
+}
+
+type noImporter struct{}
+
+func (noImporter) Import(path string) (*types.Package, error) {
+	panic("golang.org/x/tools/go/loader said this wouldn't be called")
+}
+
+func computeEdits(importPaths []string, os, arch string, cgoEnabled bool) fileToEditSet {
+	ctxt := build.Default
+	ctxt.GOOS = os
+	ctxt.GOARCH = arch
+	ctxt.CgoEnabled = cgoEnabled
+
+	var conf loader.Config
+	conf.Build = &ctxt
+	conf.TypeChecker.Importer = noImporter{}
+	for _, importPath := range importPaths {
+		conf.Import(importPath)
+	}
+	prog, err := conf.Load()
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	return computeEditsFromProg(prog)
+}
+
+func computeEditsFromProg(prog *loader.Program) fileToEditSet {
+	type res struct {
+		file  string
+		edits editSet
+	}
+	ch := make(chan res)
+	var wg sync.WaitGroup
+	for _, pkg := range prog.InitialPackages() {
+		for _, file := range pkg.Files {
+			pkg, file := pkg, file
+			wg.Add(1)
+			go func() {
+				defer wg.Done()
+				v := visitor{pkg: pkg, file: prog.Fset.File(file.Package), edits: make(editSet)}
+				ast.Walk(&v, file)
+				ch <- res{v.file.Name(), v.edits}
+			}()
+		}
+	}
+	go func() {
+		wg.Wait()
+		close(ch)
+	}()
+
+	m := make(fileToEditSet)
+	for r := range ch {
+		m[r.file] = r.edits
+	}
+	return m
+}
+
+type step struct {
+	n ast.Node
+	i int
+}
+
+type visitor struct {
+	pkg   *loader.PackageInfo
+	file  *token.File
+	edits editSet
+	path  []step
+}
+
+func (v *visitor) Visit(node ast.Node) ast.Visitor {
+	if node != nil {
+		v.path = append(v.path, step{n: node})
+	} else {
+		n := len(v.path)
+		v.path = v.path[:n-1]
+		if n >= 2 {
+			v.path[n-2].i++
+		}
+	}
+
+	if call, ok := node.(*ast.CallExpr); ok {
+		v.unconvert(call)
+	}
+	return v
+}
+
+func (v *visitor) unconvert(call *ast.CallExpr) {
+	// TODO(mdempsky): Handle useless multi-conversions.
+
+	// Conversions have exactly one argument.
+	if len(call.Args) != 1 || call.Ellipsis != token.NoPos {
+		return
+	}
+	ft, ok := v.pkg.Types[call.Fun]
+	if !ok {
+		fmt.Println("Missing type for function")
+		return
+	}
+	if !ft.IsType() {
+		// Function call; not a conversion.
+		return
+	}
+	at, ok := v.pkg.Types[call.Args[0]]
+	if !ok {
+		fmt.Println("Missing type for argument")
+		return
+	}
+	if !types.Identical(ft.Type, at.Type) {
+		// A real conversion.
+		return
+	}
+	if isUntypedValue(call.Args[0], &v.pkg.Info) {
+		// Workaround golang.org/issue/13061.
+		return
+	}
+	if *flagSafe && !v.isSafeContext(at.Type) {
+		// TODO(mdempsky): Remove this message.
+		fmt.Println("Skipped a possible type conversion because of -safe at", v.file.Position(call.Pos()))
+		return
+	}
+	if v.isCgoCheckPointerContext() {
+		// cmd/cgo generates explicit type conversions that
+		// are often redundant when introducing
+		// _cgoCheckPointer calls (issue #16).  Users can't do
+		// anything about these, so skip over them.
+		return
+	}
+
+	v.edits[v.file.Position(call.Lparen)] = struct{}{}
+}
+
+func (v *visitor) isCgoCheckPointerContext() bool {
+	ctxt := &v.path[len(v.path)-2]
+	if ctxt.i != 1 {
+		return false
+	}
+	call, ok := ctxt.n.(*ast.CallExpr)
+	if !ok {
+		return false
+	}
+	ident, ok := call.Fun.(*ast.Ident)
+	if !ok {
+		return false
+	}
+	return ident.Name == "_cgoCheckPointer"
+}
+
+// isSafeContext reports whether the current context requires
+// an expression of type t.
+//
+// TODO(mdempsky): That's a bad explanation.
+func (v *visitor) isSafeContext(t types.Type) bool {
+	ctxt := &v.path[len(v.path)-2]
+	switch n := ctxt.n.(type) {
+	case *ast.AssignStmt:
+		pos := ctxt.i - len(n.Lhs)
+		if pos < 0 {
+			fmt.Println("Type conversion on LHS of assignment?")
+			return false
+		}
+		if n.Tok == token.DEFINE {
+			// Skip := assignments.
+			return true
+		}
+		// We're a conversion in the pos'th element of n.Rhs.
+		// Check that the corresponding element of n.Lhs is of type t.
+		lt, ok := v.pkg.Types[n.Lhs[pos]]
+		if !ok {
+			fmt.Println("Missing type for LHS expression")
+			return false
+		}
+		return types.Identical(t, lt.Type)
+	case *ast.BinaryExpr:
+		if n.Op == token.SHL || n.Op == token.SHR {
+			if ctxt.i == 1 {
+				// RHS of a shift is always safe.
+				return true
+			}
+			// For the LHS, we should inspect up another level.
+			fmt.Println("TODO(mdempsky): Handle LHS of shift expressions")
+			return true
+		}
+		var other ast.Expr
+		if ctxt.i == 0 {
+			other = n.Y
+		} else {
+			other = n.X
+		}
+		ot, ok := v.pkg.Types[other]
+		if !ok {
+			fmt.Println("Missing type for other binop subexpr")
+			return false
+		}
+		return types.Identical(t, ot.Type)
+	case *ast.CallExpr:
+		pos := ctxt.i - 1
+		if pos < 0 {
+			// Type conversion in the function subexpr is okay.
+			return true
+		}
+		ft, ok := v.pkg.Types[n.Fun]
+		if !ok {
+			fmt.Println("Missing type for function expression")
+			return false
+		}
+		sig, ok := ft.Type.(*types.Signature)
+		if !ok {
+			// "Function" is either a type conversion (ok) or a builtin (ok?).
+			return true
+		}
+		params := sig.Params()
+		var pt types.Type
+		if sig.Variadic() && n.Ellipsis == token.NoPos && pos >= params.Len()-1 {
+			pt = params.At(params.Len() - 1).Type().(*types.Slice).Elem()
+		} else {
+			pt = params.At(pos).Type()
+		}
+		return types.Identical(t, pt)
+	case *ast.CompositeLit, *ast.KeyValueExpr:
+		fmt.Println("TODO(mdempsky): Compare against value type of composite literal type at", v.file.Position(n.Pos()))
+		return true
+	case *ast.ReturnStmt:
+		// TODO(mdempsky): Is there a better way to get the corresponding
+		// return parameter type?
+		var funcType *ast.FuncType
+		for i := len(v.path) - 1; funcType == nil && i >= 0; i-- {
+			switch f := v.path[i].n.(type) {
+			case *ast.FuncDecl:
+				funcType = f.Type
+			case *ast.FuncLit:
+				funcType = f.Type
+			}
+		}
+		var typeExpr ast.Expr
+		for i, j := ctxt.i, 0; j < len(funcType.Results.List); j++ {
+			f := funcType.Results.List[j]
+			if len(f.Names) == 0 {
+				if i >= 1 {
+					i--
+					continue
+				}
+			} else {
+				if i >= len(f.Names) {
+					i -= len(f.Names)
+					continue
+				}
+			}
+			typeExpr = f.Type
+			break
+		}
+		if typeExpr == nil {
+			fmt.Println(ctxt)
+		}
+		pt, ok := v.pkg.Types[typeExpr]
+		if !ok {
+			fmt.Println("Missing type for return parameter at", v.file.Position(n.Pos()))
+			return false
+		}
+		return types.Identical(t, pt.Type)
+	case *ast.StarExpr, *ast.UnaryExpr:
+		// TODO(mdempsky): I think these are always safe.
+		return true
+	case *ast.SwitchStmt:
+		// TODO(mdempsky): I think this is always safe?
+		return true
+	default:
+		// TODO(mdempsky): When can this happen?
+		fmt.Printf("... huh, %T at %v\n", n, v.file.Position(n.Pos()))
+		return true
+	}
+}
+
+func isUntypedValue(n ast.Expr, info *types.Info) (res bool) {
+	switch n := n.(type) {
+	case *ast.BinaryExpr:
+		switch n.Op {
+		case token.SHL, token.SHR:
+			// Shifts yield an untyped value if their LHS is untyped.
+			return isUntypedValue(n.X, info)
+		case token.EQL, token.NEQ, token.LSS, token.GTR, token.LEQ, token.GEQ:
+			// Comparisons yield an untyped boolean value.
+			return true
+		case token.ADD, token.SUB, token.MUL, token.QUO, token.REM,
+			token.AND, token.OR, token.XOR, token.AND_NOT,
+			token.LAND, token.LOR:
+			return isUntypedValue(n.X, info) && isUntypedValue(n.Y, info)
+		}
+	case *ast.UnaryExpr:
+		switch n.Op {
+		case token.ADD, token.SUB, token.NOT, token.XOR:
+			return isUntypedValue(n.X, info)
+		}
+	case *ast.BasicLit:
+		// Basic literals are always untyped.
+		return true
+	case *ast.ParenExpr:
+		return isUntypedValue(n.X, info)
+	case *ast.SelectorExpr:
+		return isUntypedValue(n.Sel, info)
+	case *ast.Ident:
+		if obj, ok := info.Uses[n]; ok {
+			if obj.Pkg() == nil && obj.Name() == "nil" {
+				// The universal untyped zero value.
+				return true
+			}
+			if b, ok := obj.Type().(*types.Basic); ok && b.Info()&types.IsUntyped != 0 {
+				// Reference to an untyped constant.
+				return true
+			}
+		}
+	case *ast.CallExpr:
+		if b, ok := asBuiltin(n.Fun, info); ok {
+			switch b.Name() {
+			case "real", "imag":
+				return isUntypedValue(n.Args[0], info)
+			case "complex":
+				return isUntypedValue(n.Args[0], info) && isUntypedValue(n.Args[1], info)
+			}
+		}
+	}
+
+	return false
+}
+
+func asBuiltin(n ast.Expr, info *types.Info) (*types.Builtin, bool) {
+	for {
+		paren, ok := n.(*ast.ParenExpr)
+		if !ok {
+			break
+		}
+		n = paren.X
+	}
+
+	ident, ok := n.(*ast.Ident)
+	if !ok {
+		return nil, false
+	}
+
+	obj, ok := info.Uses[ident]
+	if !ok {
+		return nil, false
+	}
+
+	b, ok := obj.(*types.Builtin)
+	return b, ok
+}
+
+type byPosition []token.Position
+
+func (p byPosition) Len() int {
+	return len(p)
+}
+
+func (p byPosition) Less(i, j int) bool {
+	if p[i].Filename != p[j].Filename {
+		return p[i].Filename < p[j].Filename
+	}
+	if p[i].Line != p[j].Line {
+		return p[i].Line < p[j].Line
+	}
+	return p[i].Column < p[j].Column
+}
+
+func (p byPosition) Swap(i, j int) {
+	p[i], p[j] = p[j], p[i]
+}

vendor/golang.org/x/text/AUTHORS

@@ -0,0 +1,3 @@
+# This source code refers to The Go Authors for copyright purposes.
+# The master list of authors is in the main Go distribution,
+# visible at http://tip.golang.org/AUTHORS.

vendor/golang.org/x/text/CONTRIBUTORS

@@ -0,0 +1,3 @@
+# This source code was written by the Go contributors.
+# The master list of contributors is in the main Go distribution,
+# visible at http://tip.golang.org/CONTRIBUTORS.

vendor/golang.org/x/text/LICENSE

@@ -0,0 +1,27 @@
+Copyright (c) 2009 The Go Authors. All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are
+met:
+
+   * Redistributions of source code must retain the above copyright
+notice, this list of conditions and the following disclaimer.
+   * Redistributions in binary form must reproduce the above
+copyright notice, this list of conditions and the following disclaimer
+in the documentation and/or other materials provided with the
+distribution.
+   * Neither the name of Google Inc. nor the names of its
+contributors may be used to endorse or promote products derived from
+this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

vendor/golang.org/x/text/PATENTS

@@ -0,0 +1,22 @@
+Additional IP Rights Grant (Patents)
+
+"This implementation" means the copyrightable works distributed by
+Google as part of the Go project.
+
+Google hereby grants to You a perpetual, worldwide, non-exclusive,
+no-charge, royalty-free, irrevocable (except as stated in this section)
+patent license to make, have made, use, offer to sell, sell, import,
+transfer and otherwise run, modify and propagate the contents of this
+implementation of Go, where such license applies only to those patent
+claims, both currently owned or controlled by Google and acquired in
+the future, licensable by Google that are necessarily infringed by this
+implementation of Go.  This grant does not include claims that would be
+infringed only as a consequence of further modification of this
+implementation.  If you or your agent or exclusive licensee institute or
+order or agree to the institution of patent litigation against any
+entity (including a cross-claim or counterclaim in a lawsuit) alleging
+that this implementation of Go or any code incorporated within this
+implementation of Go constitutes direct or contributory patent
+infringement, or inducement of patent infringement, then any patent
+rights granted to you under this License for this implementation of Go
+shall terminate as of the date such litigation is filed.

vendor/golang.org/x/text/internal/gen/code.go

@@ -0,0 +1,369 @@
+// Copyright 2015 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package gen
+
+import (
+	"bytes"
+	"encoding/gob"
+	"fmt"
+	"hash"
+	"hash/fnv"
+	"io"
+	"log"
+	"os"
+	"reflect"
+	"strings"
+	"unicode"
+	"unicode/utf8"
+)
+
+// This file contains utilities for generating code.
+
+// TODO: other write methods like:
+// - slices, maps, types, etc.
+
+// CodeWriter is a utility for writing structured code. It computes the content
+// hash and size of written content. It ensures there are newlines between
+// written code blocks.
+type CodeWriter struct {
+	buf  bytes.Buffer
+	Size int
+	Hash hash.Hash32 // content hash
+	gob  *gob.Encoder
+	// For comments we skip the usual one-line separator if they are followed by
+	// a code block.
+	skipSep bool
+}
+
+func (w *CodeWriter) Write(p []byte) (n int, err error) {
+	return w.buf.Write(p)
+}
+
+// NewCodeWriter returns a new CodeWriter.
+func NewCodeWriter() *CodeWriter {
+	h := fnv.New32()
+	return &CodeWriter{Hash: h, gob: gob.NewEncoder(h)}
+}
+
+// WriteGoFile appends the buffer with the total size of all created structures
+// and writes it as a Go file to the the given file with the given package name.
+func (w *CodeWriter) WriteGoFile(filename, pkg string) {
+	f, err := os.Create(filename)
+	if err != nil {
+		log.Fatalf("Could not create file %s: %v", filename, err)
+	}
+	defer f.Close()
+	if _, err = w.WriteGo(f, pkg, ""); err != nil {
+		log.Fatalf("Error writing file %s: %v", filename, err)
+	}
+}
+
+// WriteVersionedGoFile appends the buffer with the total size of all created
+// structures and writes it as a Go file to the the given file with the given
+// package name and build tags for the current Unicode version,
+func (w *CodeWriter) WriteVersionedGoFile(filename, pkg string) {
+	tags := buildTags()
+	if tags != "" {
+		filename = insertVersion(filename, UnicodeVersion())
+	}
+	f, err := os.Create(filename)
+	if err != nil {
+		log.Fatalf("Could not create file %s: %v", filename, err)
+	}
+	defer f.Close()
+	if _, err = w.WriteGo(f, pkg, tags); err != nil {
+		log.Fatalf("Error writing file %s: %v", filename, err)
+	}
+}
+
+// WriteGo appends the buffer with the total size of all created structures and
+// writes it as a Go file to the the given writer with the given package name.
+func (w *CodeWriter) WriteGo(out io.Writer, pkg, tags string) (n int, err error) {
+	sz := w.Size
+	w.WriteComment("Total table size %d bytes (%dKiB); checksum: %X\n", sz, sz/1024, w.Hash.Sum32())
+	defer w.buf.Reset()
+	return WriteGo(out, pkg, tags, w.buf.Bytes())
+}
+
+func (w *CodeWriter) printf(f string, x ...interface{}) {
+	fmt.Fprintf(w, f, x...)
+}
+
+func (w *CodeWriter) insertSep() {
+	if w.skipSep {
+		w.skipSep = false
+		return
+	}
+	// Use at least two newlines to ensure a blank space between the previous
+	// block. WriteGoFile will remove extraneous newlines.
+	w.printf("\n\n")
+}
+
+// WriteComment writes a comment block. All line starts are prefixed with "//".
+// Initial empty lines are gobbled. The indentation for the first line is
+// stripped from consecutive lines.
+func (w *CodeWriter) WriteComment(comment string, args ...interface{}) {
+	s := fmt.Sprintf(comment, args...)
+	s = strings.Trim(s, "\n")
+
+	// Use at least two newlines to ensure a blank space between the previous
+	// block. WriteGoFile will remove extraneous newlines.
+	w.printf("\n\n// ")
+	w.skipSep = true
+
+	// strip first indent level.
+	sep := "\n"
+	for ; len(s) > 0 && (s[0] == '\t' || s[0] == ' '); s = s[1:] {
+		sep += s[:1]
+	}
+
+	strings.NewReplacer(sep, "\n// ", "\n", "\n// ").WriteString(w, s)
+
+	w.printf("\n")
+}
+
+func (w *CodeWriter) writeSizeInfo(size int) {
+	w.printf("// Size: %d bytes\n", size)
+}
+
+// WriteConst writes a constant of the given name and value.
+func (w *CodeWriter) WriteConst(name string, x interface{}) {
+	w.insertSep()
+	v := reflect.ValueOf(x)
+
+	switch v.Type().Kind() {
+	case reflect.String:
+		w.printf("const %s %s = ", name, typeName(x))
+		w.WriteString(v.String())
+		w.printf("\n")
+	default:
+		w.printf("const %s = %#v\n", name, x)
+	}
+}
+
+// WriteVar writes a variable of the given name and value.
+func (w *CodeWriter) WriteVar(name string, x interface{}) {
+	w.insertSep()
+	v := reflect.ValueOf(x)
+	oldSize := w.Size
+	sz := int(v.Type().Size())
+	w.Size += sz
+
+	switch v.Type().Kind() {
+	case reflect.String:
+		w.printf("var %s %s = ", name, typeName(x))
+		w.WriteString(v.String())
+	case reflect.Struct:
+		w.gob.Encode(x)
+		fallthrough
+	case reflect.Slice, reflect.Array:
+		w.printf("var %s = ", name)
+		w.writeValue(v)
+		w.writeSizeInfo(w.Size - oldSize)
+	default:
+		w.printf("var %s %s = ", name, typeName(x))
+		w.gob.Encode(x)
+		w.writeValue(v)
+		w.writeSizeInfo(w.Size - oldSize)
+	}
+	w.printf("\n")
+}
+
+func (w *CodeWriter) writeValue(v reflect.Value) {
+	x := v.Interface()
+	switch v.Kind() {
+	case reflect.String:
+		w.WriteString(v.String())
+	case reflect.Array:
+		// Don't double count: callers of WriteArray count on the size being
+		// added, so we need to discount it here.
+		w.Size -= int(v.Type().Size())
+		w.writeSlice(x, true)
+	case reflect.Slice:
+		w.writeSlice(x, false)
+	case reflect.Struct:
+		w.printf("%s{\n", typeName(v.Interface()))
+		t := v.Type()
+		for i := 0; i < v.NumField(); i++ {
+			w.printf("%s: ", t.Field(i).Name)
+			w.writeValue(v.Field(i))
+			w.printf(",\n")
+		}
+		w.printf("}")
+	default:
+		w.printf("%#v", x)
+	}
+}
+
+// WriteString writes a string literal.
+func (w *CodeWriter) WriteString(s string) {
+	s = strings.Replace(s, `\`, `\\`, -1)
+	io.WriteString(w.Hash, s) // content hash
+	w.Size += len(s)
+
+	const maxInline = 40
+	if len(s) <= maxInline {
+		w.printf("%q", s)
+		return
+	}
+
+	// We will render the string as a multi-line string.
+	const maxWidth = 80 - 4 - len(`"`) - len(`" +`)
+
+	// When starting on its own line, go fmt indents line 2+ an extra level.
+	n, max := maxWidth, maxWidth-4
+
+	// As per https://golang.org/issue/18078, the compiler has trouble
+	// compiling the concatenation of many strings, s0 + s1 + s2 + ... + sN,
+	// for large N. We insert redundant, explicit parentheses to work around
+	// that, lowering the N at any given step: (s0 + s1 + ... + s63) + (s64 +
+	// ... + s127) + etc + (etc + ... + sN).
+	explicitParens, extraComment := len(s) > 128*1024, ""
+	if explicitParens {
+		w.printf(`(`)
+		extraComment = "; the redundant, explicit parens are for https://golang.org/issue/18078"
+	}
+
+	// Print "" +\n, if a string does not start on its own line.
+	b := w.buf.Bytes()
+	if p := len(bytes.TrimRight(b, " \t")); p > 0 && b[p-1] != '\n' {
+		w.printf("\"\" + // Size: %d bytes%s\n", len(s), extraComment)
+		n, max = maxWidth, maxWidth
+	}
+
+	w.printf(`"`)
+
+	for sz, p, nLines := 0, 0, 0; p < len(s); {
+		var r rune
+		r, sz = utf8.DecodeRuneInString(s[p:])
+		out := s[p : p+sz]
+		chars := 1
+		if !unicode.IsPrint(r) || r == utf8.RuneError || r == '"' {
+			switch sz {
+			case 1:
+				out = fmt.Sprintf("\\x%02x", s[p])
+			case 2, 3:
+				out = fmt.Sprintf("\\u%04x", r)
+			case 4:
+				out = fmt.Sprintf("\\U%08x", r)
+			}
+			chars = len(out)
+		}
+		if n -= chars; n < 0 {
+			nLines++
+			if explicitParens && nLines&63 == 63 {
+				w.printf("\") + (\"")
+			}
+			w.printf("\" +\n\"")
+			n = max - len(out)
+		}
+		w.printf("%s", out)
+		p += sz
+	}
+	w.printf(`"`)
+	if explicitParens {
+		w.printf(`)`)
+	}
+}
+
+// WriteSlice writes a slice value.
+func (w *CodeWriter) WriteSlice(x interface{}) {
+	w.writeSlice(x, false)
+}
+
+// WriteArray writes an array value.
+func (w *CodeWriter) WriteArray(x interface{}) {
+	w.writeSlice(x, true)
+}
+
+func (w *CodeWriter) writeSlice(x interface{}, isArray bool) {
+	v := reflect.ValueOf(x)
+	w.gob.Encode(v.Len())
+	w.Size += v.Len() * int(v.Type().Elem().Size())
+	name := typeName(x)
+	if isArray {
+		name = fmt.Sprintf("[%d]%s", v.Len(), name[strings.Index(name, "]")+1:])
+	}
+	if isArray {
+		w.printf("%s{\n", name)
+	} else {
+		w.printf("%s{ // %d elements\n", name, v.Len())
+	}
+
+	switch kind := v.Type().Elem().Kind(); kind {
+	case reflect.String:
+		for _, s := range x.([]string) {
+			w.WriteString(s)
+			w.printf(",\n")
+		}
+	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64,
+		reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64:
+		// nLine and nBlock are the number of elements per line and block.
+		nLine, nBlock, format := 8, 64, "%d,"
+		switch kind {
+		case reflect.Uint8:
+			format = "%#02x,"
+		case reflect.Uint16:
+			format = "%#04x,"
+		case reflect.Uint32:
+			nLine, nBlock, format = 4, 32, "%#08x,"
+		case reflect.Uint, reflect.Uint64:
+			nLine, nBlock, format = 4, 32, "%#016x,"
+		case reflect.Int8:
+			nLine = 16
+		}
+		n := nLine
+		for i := 0; i < v.Len(); i++ {
+			if i%nBlock == 0 && v.Len() > nBlock {
+				w.printf("// Entry %X - %X\n", i, i+nBlock-1)
+			}
+			x := v.Index(i).Interface()
+			w.gob.Encode(x)
+			w.printf(format, x)
+			if n--; n == 0 {
+				n = nLine
+				w.printf("\n")
+			}
+		}
+		w.printf("\n")
+	case reflect.Struct:
+		zero := reflect.Zero(v.Type().Elem()).Interface()
+		for i := 0; i < v.Len(); i++ {
+			x := v.Index(i).Interface()
+			w.gob.EncodeValue(v)
+			if !reflect.DeepEqual(zero, x) {
+				line := fmt.Sprintf("%#v,\n", x)
+				line = line[strings.IndexByte(line, '{'):]
+				w.printf("%d: ", i)
+				w.printf(line)
+			}
+		}
+	case reflect.Array:
+		for i := 0; i < v.Len(); i++ {
+			w.printf("%d: %#v,\n", i, v.Index(i).Interface())
+		}
+	default:
+		panic("gen: slice elem type not supported")
+	}
+	w.printf("}")
+}
+
+// WriteType writes a definition of the type of the given value and returns the
+// type name.
+func (w *CodeWriter) WriteType(x interface{}) string {
+	t := reflect.TypeOf(x)
+	w.printf("type %s struct {\n", t.Name())
+	for i := 0; i < t.NumField(); i++ {
+		w.printf("\t%s %s\n", t.Field(i).Name, t.Field(i).Type)
+	}
+	w.printf("}\n")
+	return t.Name()
+}
+
+// typeName returns the name of the go type of x.
+func typeName(x interface{}) string {
+	t := reflect.ValueOf(x).Type()
+	return strings.Replace(fmt.Sprint(t), "main.", "", 1)
+}

vendor/golang.org/x/text/internal/gen/gen.go

@@ -0,0 +1,333 @@
+// Copyright 2015 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package gen contains common code for the various code generation tools in the
+// text repository. Its usage ensures consistency between tools.
+//
+// This package defines command line flags that are common to most generation
+// tools. The flags allow for specifying specific Unicode and CLDR versions
+// in the public Unicode data repository (http://www.unicode.org/Public).
+//
+// A local Unicode data mirror can be set through the flag -local or the
+// environment variable UNICODE_DIR. The former takes precedence. The local
+// directory should follow the same structure as the public repository.
+//
+// IANA data can also optionally be mirrored by putting it in the iana directory
+// rooted at the top of the local mirror. Beware, though, that IANA data is not
+// versioned. So it is up to the developer to use the right version.
+package gen // import "golang.org/x/text/internal/gen"
+
+import (
+	"bytes"
+	"flag"
+	"fmt"
+	"go/build"
+	"go/format"
+	"io"
+	"io/ioutil"
+	"log"
+	"net/http"
+	"os"
+	"path"
+	"path/filepath"
+	"strings"
+	"sync"
+	"unicode"
+
+	"golang.org/x/text/unicode/cldr"
+)
+
+var (
+	url = flag.String("url",
+		"http://www.unicode.org/Public",
+		"URL of Unicode database directory")
+	iana = flag.String("iana",
+		"http://www.iana.org",
+		"URL of the IANA repository")
+	unicodeVersion = flag.String("unicode",
+		getEnv("UNICODE_VERSION", unicode.Version),
+		"unicode version to use")
+	cldrVersion = flag.String("cldr",
+		getEnv("CLDR_VERSION", cldr.Version),
+		"cldr version to use")
+)
+
+func getEnv(name, def string) string {
+	if v := os.Getenv(name); v != "" {
+		return v
+	}
+	return def
+}
+
+// Init performs common initialization for a gen command. It parses the flags
+// and sets up the standard logging parameters.
+func Init() {
+	log.SetPrefix("")
+	log.SetFlags(log.Lshortfile)
+	flag.Parse()
+}
+
+const header = `// Code generated by running "go generate" in golang.org/x/text. DO NOT EDIT.
+
+`
+
+// UnicodeVersion reports the requested Unicode version.
+func UnicodeVersion() string {
+	return *unicodeVersion
+}
+
+// CLDRVersion reports the requested CLDR version.
+func CLDRVersion() string {
+	return *cldrVersion
+}
+
+var tags = []struct{ version, buildTags string }{
+	{"10.0.0", "go1.10"},
+	{"", "!go1.10"},
+}
+
+// buildTags reports the build tags used for the current Unicode version.
+func buildTags() string {
+	v := UnicodeVersion()
+	for _, x := range tags {
+		// We should do a numeric comparison, but including the collate package
+		// would create an import cycle. We approximate it by assuming that
+		// longer version strings are later.
+		if len(x.version) <= len(v) {
+			return x.buildTags
+		}
+		if len(x.version) == len(v) && x.version <= v {
+			return x.buildTags
+		}
+	}
+	return tags[0].buildTags
+}
+
+// IsLocal reports whether data files are available locally.
+func IsLocal() bool {
+	dir, err := localReadmeFile()
+	if err != nil {
+		return false
+	}
+	if _, err = os.Stat(dir); err != nil {
+		return false
+	}
+	return true
+}
+
+// OpenUCDFile opens the requested UCD file. The file is specified relative to
+// the public Unicode root directory. It will call log.Fatal if there are any
+// errors.
+func OpenUCDFile(file string) io.ReadCloser {
+	return openUnicode(path.Join(*unicodeVersion, "ucd", file))
+}
+
+// OpenCLDRCoreZip opens the CLDR core zip file. It will call log.Fatal if there
+// are any errors.
+func OpenCLDRCoreZip() io.ReadCloser {
+	return OpenUnicodeFile("cldr", *cldrVersion, "core.zip")
+}
+
+// OpenUnicodeFile opens the requested file of the requested category from the
+// root of the Unicode data archive. The file is specified relative to the
+// public Unicode root directory. If version is "", it will use the default
+// Unicode version. It will call log.Fatal if there are any errors.
+func OpenUnicodeFile(category, version, file string) io.ReadCloser {
+	if version == "" {
+		version = UnicodeVersion()
+	}
+	return openUnicode(path.Join(category, version, file))
+}
+
+// OpenIANAFile opens the requested IANA file. The file is specified relative
+// to the IANA root, which is typically either http://www.iana.org or the
+// iana directory in the local mirror. It will call log.Fatal if there are any
+// errors.
+func OpenIANAFile(path string) io.ReadCloser {
+	return Open(*iana, "iana", path)
+}
+
+var (
+	dirMutex sync.Mutex
+	localDir string
+)
+
+const permissions = 0755
+
+func localReadmeFile() (string, error) {
+	p, err := build.Import("golang.org/x/text", "", build.FindOnly)
+	if err != nil {
+		return "", fmt.Errorf("Could not locate package: %v", err)
+	}
+	return filepath.Join(p.Dir, "DATA", "README"), nil
+}
+
+func getLocalDir() string {
+	dirMutex.Lock()
+	defer dirMutex.Unlock()
+
+	readme, err := localReadmeFile()
+	if err != nil {
+		log.Fatal(err)
+	}
+	dir := filepath.Dir(readme)
+	if _, err := os.Stat(readme); err != nil {
+		if err := os.MkdirAll(dir, permissions); err != nil {
+			log.Fatalf("Could not create directory: %v", err)
+		}
+		ioutil.WriteFile(readme, []byte(readmeTxt), permissions)
+	}
+	return dir
+}
+
+const readmeTxt = `Generated by golang.org/x/text/internal/gen. DO NOT EDIT.
+
+This directory contains downloaded files used to generate the various tables
+in the golang.org/x/text subrepo.
+
+Note that the language subtag repo (iana/assignments/language-subtag-registry)
+and all other times in the iana subdirectory are not versioned and will need
+to be periodically manually updated. The easiest way to do this is to remove
+the entire iana directory. This is mostly of concern when updating the language
+package.
+`
+
+// Open opens subdir/path if a local directory is specified and the file exists,
+// where subdir is a directory relative to the local root, or fetches it from
+// urlRoot/path otherwise. It will call log.Fatal if there are any errors.
+func Open(urlRoot, subdir, path string) io.ReadCloser {
+	file := filepath.Join(getLocalDir(), subdir, filepath.FromSlash(path))
+	return open(file, urlRoot, path)
+}
+
+func openUnicode(path string) io.ReadCloser {
+	file := filepath.Join(getLocalDir(), filepath.FromSlash(path))
+	return open(file, *url, path)
+}
+
+// TODO: automatically periodically update non-versioned files.
+
+func open(file, urlRoot, path string) io.ReadCloser {
+	if f, err := os.Open(file); err == nil {
+		return f
+	}
+	r := get(urlRoot, path)
+	defer r.Close()
+	b, err := ioutil.ReadAll(r)
+	if err != nil {
+		log.Fatalf("Could not download file: %v", err)
+	}
+	os.MkdirAll(filepath.Dir(file), permissions)
+	if err := ioutil.WriteFile(file, b, permissions); err != nil {
+		log.Fatalf("Could not create file: %v", err)
+	}
+	return ioutil.NopCloser(bytes.NewReader(b))
+}
+
+func get(root, path string) io.ReadCloser {
+	url := root + "/" + path
+	fmt.Printf("Fetching %s...", url)
+	defer fmt.Println(" done.")
+	resp, err := http.Get(url)
+	if err != nil {
+		log.Fatalf("HTTP GET: %v", err)
+	}
+	if resp.StatusCode != 200 {
+		log.Fatalf("Bad GET status for %q: %q", url, resp.Status)
+	}
+	return resp.Body
+}
+
+// TODO: use Write*Version in all applicable packages.
+
+// WriteUnicodeVersion writes a constant for the Unicode version from which the
+// tables are generated.
+func WriteUnicodeVersion(w io.Writer) {
+	fmt.Fprintf(w, "// UnicodeVersion is the Unicode version from which the tables in this package are derived.\n")
+	fmt.Fprintf(w, "const UnicodeVersion = %q\n\n", UnicodeVersion())
+}
+
+// WriteCLDRVersion writes a constant for the CLDR version from which the
+// tables are generated.
+func WriteCLDRVersion(w io.Writer) {
+	fmt.Fprintf(w, "// CLDRVersion is the CLDR version from which the tables in this package are derived.\n")
+	fmt.Fprintf(w, "const CLDRVersion = %q\n\n", CLDRVersion())
+}
+
+// WriteGoFile prepends a standard file comment and package statement to the
+// given bytes, applies gofmt, and writes them to a file with the given name.
+// It will call log.Fatal if there are any errors.
+func WriteGoFile(filename, pkg string, b []byte) {
+	w, err := os.Create(filename)
+	if err != nil {
+		log.Fatalf("Could not create file %s: %v", filename, err)
+	}
+	defer w.Close()
+	if _, err = WriteGo(w, pkg, "", b); err != nil {
+		log.Fatalf("Error writing file %s: %v", filename, err)
+	}
+}
+
+func insertVersion(filename, version string) string {
+	suffix := ".go"
+	if strings.HasSuffix(filename, "_test.go") {
+		suffix = "_test.go"
+	}
+	return fmt.Sprint(filename[:len(filename)-len(suffix)], version, suffix)
+}
+
+// WriteVersionedGoFile prepends a standard file comment, adds build tags to
+// version the file for the current Unicode version, and package statement to
+// the given bytes, applies gofmt, and writes them to a file with the given
+// name. It will call log.Fatal if there are any errors.
+func WriteVersionedGoFile(filename, pkg string, b []byte) {
+	tags := buildTags()
+	if tags != "" {
+		filename = insertVersion(filename, UnicodeVersion())
+	}
+	w, err := os.Create(filename)
+	if err != nil {
+		log.Fatalf("Could not create file %s: %v", filename, err)
+	}
+	defer w.Close()
+	if _, err = WriteGo(w, pkg, tags, b); err != nil {
+		log.Fatalf("Error writing file %s: %v", filename, err)
+	}
+}
+
+// WriteGo prepends a standard file comment and package statement to the given
+// bytes, applies gofmt, and writes them to w.
+func WriteGo(w io.Writer, pkg, tags string, b []byte) (n int, err error) {
+	src := []byte(header)
+	if tags != "" {
+		src = append(src, fmt.Sprintf("// +build %s\n\n", tags)...)
+	}
+	src = append(src, fmt.Sprintf("package %s\n\n", pkg)...)
+	src = append(src, b...)
+	formatted, err := format.Source(src)
+	if err != nil {
+		// Print the generated code even in case of an error so that the
+		// returned error can be meaningfully interpreted.
+		n, _ = w.Write(src)
+		return n, err
+	}
+	return w.Write(formatted)
+}
+
+// Repackage rewrites a Go file from belonging to package main to belonging to
+// the given package.
+func Repackage(inFile, outFile, pkg string) {
+	src, err := ioutil.ReadFile(inFile)
+	if err != nil {
+		log.Fatalf("reading %s: %v", inFile, err)
+	}
+	const toDelete = "package main\n\n"
+	i := bytes.Index(src, []byte(toDelete))
+	if i < 0 {
+		log.Fatalf("Could not find %q in %s.", toDelete, inFile)
+	}
+	w := &bytes.Buffer{}
+	w.Write(src[i+len(toDelete):])
+	WriteGoFile(outFile, pkg, w.Bytes())
+}

vendor/golang.org/x/text/internal/triegen/compact.go

@@ -0,0 +1,58 @@
+// Copyright 2014 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package triegen
+
+// This file defines Compacter and its implementations.
+
+import "io"
+
+// A Compacter generates an alternative, more space-efficient way to store a
+// trie value block. A trie value block holds all possible values for the last
+// byte of a UTF-8 encoded rune. Excluding ASCII characters, a trie value block
+// always has 64 values, as a UTF-8 encoding ends with a byte in [0x80, 0xC0).
+type Compacter interface {
+	// Size returns whether the Compacter could encode the given block as well
+	// as its size in case it can. len(v) is always 64.
+	Size(v []uint64) (sz int, ok bool)
+
+	// Store stores the block using the Compacter's compression method.
+	// It returns a handle with which the block can be retrieved.
+	// len(v) is always 64.
+	Store(v []uint64) uint32
+
+	// Print writes the data structures associated to the given store to w.
+	Print(w io.Writer) error
+
+	// Handler returns the name of a function that gets called during trie
+	// lookup for blocks generated by the Compacter. The function should be of
+	// the form func (n uint32, b byte) uint64, where n is the index returned by
+	// the Compacter's Store method and b is the last byte of the UTF-8
+	// encoding, where 0x80 <= b < 0xC0, for which to do the lookup in the
+	// block.
+	Handler() string
+}
+
+// simpleCompacter is the default Compacter used by builder. It implements a
+// normal trie block.
+type simpleCompacter builder
+
+func (b *simpleCompacter) Size([]uint64) (sz int, ok bool) {
+	return blockSize * b.ValueSize, true
+}
+
+func (b *simpleCompacter) Store(v []uint64) uint32 {
+	h := uint32(len(b.ValueBlocks) - blockOffset)
+	b.ValueBlocks = append(b.ValueBlocks, v)
+	return h
+}
+
+func (b *simpleCompacter) Print(io.Writer) error {
+	// Structures are printed in print.go.
+	return nil
+}
+
+func (b *simpleCompacter) Handler() string {
+	panic("Handler should be special-cased for this Compacter")
+}

vendor/golang.org/x/text/internal/triegen/print.go

@@ -0,0 +1,251 @@
+// Copyright 2014 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package triegen
+
+import (
+	"bytes"
+	"fmt"
+	"io"
+	"strings"
+	"text/template"
+)
+
+// print writes all the data structures as well as the code necessary to use the
+// trie to w.
+func (b *builder) print(w io.Writer) error {
+	b.Stats.NValueEntries = len(b.ValueBlocks) * blockSize
+	b.Stats.NValueBytes = len(b.ValueBlocks) * blockSize * b.ValueSize
+	b.Stats.NIndexEntries = len(b.IndexBlocks) * blockSize
+	b.Stats.NIndexBytes = len(b.IndexBlocks) * blockSize * b.IndexSize
+	b.Stats.NHandleBytes = len(b.Trie) * 2 * b.IndexSize
+
+	// If we only have one root trie, all starter blocks are at position 0 and
+	// we can access the arrays directly.
+	if len(b.Trie) == 1 {
+		// At this point we cannot refer to the generated tables directly.
+		b.ASCIIBlock = b.Name + "Values"
+		b.StarterBlock = b.Name + "Index"
+	} else {
+		// Otherwise we need to have explicit starter indexes in the trie
+		// structure.
+		b.ASCIIBlock = "t.ascii"
+		b.StarterBlock = "t.utf8Start"
+	}
+
+	b.SourceType = "[]byte"
+	if err := lookupGen.Execute(w, b); err != nil {
+		return err
+	}
+
+	b.SourceType = "string"
+	if err := lookupGen.Execute(w, b); err != nil {
+		return err
+	}
+
+	if err := trieGen.Execute(w, b); err != nil {
+		return err
+	}
+
+	for _, c := range b.Compactions {
+		if err := c.c.Print(w); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+func printValues(n int, values []uint64) string {
+	w := &bytes.Buffer{}
+	boff := n * blockSize
+	fmt.Fprintf(w, "\t// Block %#x, offset %#x", n, boff)
+	var newline bool
+	for i, v := range values {
+		if i%6 == 0 {
+			newline = true
+		}
+		if v != 0 {
+			if newline {
+				fmt.Fprintf(w, "\n")
+				newline = false
+			}
+			fmt.Fprintf(w, "\t%#02x:%#04x, ", boff+i, v)
+		}
+	}
+	return w.String()
+}
+
+func printIndex(b *builder, nr int, n *node) string {
+	w := &bytes.Buffer{}
+	boff := nr * blockSize
+	fmt.Fprintf(w, "\t// Block %#x, offset %#x", nr, boff)
+	var newline bool
+	for i, c := range n.children {
+		if i%8 == 0 {
+			newline = true
+		}
+		if c != nil {
+			v := b.Compactions[c.index.compaction].Offset + uint32(c.index.index)
+			if v != 0 {
+				if newline {
+					fmt.Fprintf(w, "\n")
+					newline = false
+				}
+				fmt.Fprintf(w, "\t%#02x:%#02x, ", boff+i, v)
+			}
+		}
+	}
+	return w.String()
+}
+
+var (
+	trieGen = template.Must(template.New("trie").Funcs(template.FuncMap{
+		"printValues": printValues,
+		"printIndex":  printIndex,
+		"title":       strings.Title,
+		"dec":         func(x int) int { return x - 1 },
+		"psize": func(n int) string {
+			return fmt.Sprintf("%d bytes (%.2f KiB)", n, float64(n)/1024)
+		},
+	}).Parse(trieTemplate))
+	lookupGen = template.Must(template.New("lookup").Parse(lookupTemplate))
+)
+
+// TODO: consider the return type of lookup. It could be uint64, even if the
+// internal value type is smaller. We will have to verify this with the
+// performance of unicode/norm, which is very sensitive to such changes.
+const trieTemplate = `{{$b := .}}{{$multi := gt (len .Trie) 1}}
+// {{.Name}}Trie. Total size: {{psize .Size}}. Checksum: {{printf "%08x" .Checksum}}.
+type {{.Name}}Trie struct { {{if $multi}}
+	ascii []{{.ValueType}} // index for ASCII bytes
+	utf8Start  []{{.IndexType}} // index for UTF-8 bytes >= 0xC0
+{{end}}}
+
+func new{{title .Name}}Trie(i int) *{{.Name}}Trie { {{if $multi}}
+	h := {{.Name}}TrieHandles[i]
+	return &{{.Name}}Trie{ {{.Name}}Values[uint32(h.ascii)<<6:], {{.Name}}Index[uint32(h.multi)<<6:] }
+}
+
+type {{.Name}}TrieHandle struct {
+	ascii, multi {{.IndexType}}
+}
+
+// {{.Name}}TrieHandles: {{len .Trie}} handles, {{.Stats.NHandleBytes}} bytes
+var {{.Name}}TrieHandles = [{{len .Trie}}]{{.Name}}TrieHandle{
+{{range .Trie}}	{ {{.ASCIIIndex}}, {{.StarterIndex}} }, // {{printf "%08x" .Checksum}}: {{.Name}}
+{{end}}}{{else}}
+	return &{{.Name}}Trie{}
+}
+{{end}}
+// lookupValue determines the type of block n and looks up the value for b.
+func (t *{{.Name}}Trie) lookupValue(n uint32, b byte) {{.ValueType}}{{$last := dec (len .Compactions)}} {
+	switch { {{range $i, $c := .Compactions}}
+		{{if eq $i $last}}default{{else}}case n < {{$c.Cutoff}}{{end}}:{{if ne $i 0}}
+			n -= {{$c.Offset}}{{end}}
+			return {{print $b.ValueType}}({{$c.Handler}}){{end}}
+	}
+}
+
+// {{.Name}}Values: {{len .ValueBlocks}} blocks, {{.Stats.NValueEntries}} entries, {{.Stats.NValueBytes}} bytes
+// The third block is the zero block.
+var {{.Name}}Values = [{{.Stats.NValueEntries}}]{{.ValueType}} {
+{{range $i, $v := .ValueBlocks}}{{printValues $i $v}}
+{{end}}}
+
+// {{.Name}}Index: {{len .IndexBlocks}} blocks, {{.Stats.NIndexEntries}} entries, {{.Stats.NIndexBytes}} bytes
+// Block 0 is the zero block.
+var {{.Name}}Index = [{{.Stats.NIndexEntries}}]{{.IndexType}} {
+{{range $i, $v := .IndexBlocks}}{{printIndex $b $i $v}}
+{{end}}}
+`
+
+// TODO: consider allowing zero-length strings after evaluating performance with
+// unicode/norm.
+const lookupTemplate = `
+// lookup{{if eq .SourceType "string"}}String{{end}} returns the trie value for the first UTF-8 encoding in s and
+// the width in bytes of this encoding. The size will be 0 if s does not
+// hold enough bytes to complete the encoding. len(s) must be greater than 0.
+func (t *{{.Name}}Trie) lookup{{if eq .SourceType "string"}}String{{end}}(s {{.SourceType}}) (v {{.ValueType}}, sz int) {
+	c0 := s[0]
+	switch {
+	case c0 < 0x80: // is ASCII
+		return {{.ASCIIBlock}}[c0], 1
+	case c0 < 0xC2:
+		return 0, 1  // Illegal UTF-8: not a starter, not ASCII.
+	case c0 < 0xE0: // 2-byte UTF-8
+		if len(s) < 2 {
+			return 0, 0
+		}
+		i := {{.StarterBlock}}[c0]
+		c1 := s[1]
+		if c1 < 0x80 || 0xC0 <= c1 {
+			return 0, 1 // Illegal UTF-8: not a continuation byte.
+		}
+		return t.lookupValue(uint32(i), c1), 2
+	case c0 < 0xF0: // 3-byte UTF-8
+		if len(s) < 3 {
+			return 0, 0
+		}
+		i := {{.StarterBlock}}[c0]
+		c1 := s[1]
+		if c1 < 0x80 || 0xC0 <= c1 {
+			return 0, 1 // Illegal UTF-8: not a continuation byte.
+		}
+		o := uint32(i)<<6 + uint32(c1)
+		i = {{.Name}}Index[o]
+		c2 := s[2]
+		if c2 < 0x80 || 0xC0 <= c2 {
+			return 0, 2 // Illegal UTF-8: not a continuation byte.
+		}
+		return t.lookupValue(uint32(i), c2), 3
+	case c0 < 0xF8: // 4-byte UTF-8
+		if len(s) < 4 {
+			return 0, 0
+		}
+		i := {{.StarterBlock}}[c0]
+		c1 := s[1]
+		if c1 < 0x80 || 0xC0 <= c1 {
+			return 0, 1 // Illegal UTF-8: not a continuation byte.
+		}
+		o := uint32(i)<<6 + uint32(c1)
+		i = {{.Name}}Index[o]
+		c2 := s[2]
+		if c2 < 0x80 || 0xC0 <= c2 {
+			return 0, 2 // Illegal UTF-8: not a continuation byte.
+		}
+		o = uint32(i)<<6 + uint32(c2)
+		i = {{.Name}}Index[o]
+		c3 := s[3]
+		if c3 < 0x80 || 0xC0 <= c3 {
+			return 0, 3 // Illegal UTF-8: not a continuation byte.
+		}
+		return t.lookupValue(uint32(i), c3), 4
+	}
+	// Illegal rune
+	return 0, 1
+}
+
+// lookup{{if eq .SourceType "string"}}String{{end}}Unsafe returns the trie value for the first UTF-8 encoding in s.
+// s must start with a full and valid UTF-8 encoded rune.
+func (t *{{.Name}}Trie) lookup{{if eq .SourceType "string"}}String{{end}}Unsafe(s {{.SourceType}}) {{.ValueType}} {
+	c0 := s[0]
+	if c0 < 0x80 { // is ASCII
+		return {{.ASCIIBlock}}[c0]
+	}
+	i := {{.StarterBlock}}[c0]
+	if c0 < 0xE0 { // 2-byte UTF-8
+		return t.lookupValue(uint32(i), s[1])
+	}
+	i = {{.Name}}Index[uint32(i)<<6+uint32(s[1])]
+	if c0 < 0xF0 { // 3-byte UTF-8
+		return t.lookupValue(uint32(i), s[2])
+	}
+	i = {{.Name}}Index[uint32(i)<<6+uint32(s[2])]
+	if c0 < 0xF8 { // 4-byte UTF-8
+		return t.lookupValue(uint32(i), s[3])
+	}
+	return 0
+}
+`

vendor/golang.org/x/text/internal/triegen/triegen.go

@@ -0,0 +1,494 @@
+// Copyright 2014 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package triegen implements a code generator for a trie for associating
+// unsigned integer values with UTF-8 encoded runes.
+//
+// Many of the go.text packages use tries for storing per-rune information.  A
+// trie is especially useful if many of the runes have the same value. If this
+// is the case, many blocks can be expected to be shared allowing for
+// information on many runes to be stored in little space.
+//
+// As most of the lookups are done directly on []byte slices, the tries use the
+// UTF-8 bytes directly for the lookup. This saves a conversion from UTF-8 to
+// runes and contributes a little bit to better performance. It also naturally
+// provides a fast path for ASCII.
+//
+// Space is also an issue. There are many code points defined in Unicode and as
+// a result tables can get quite large. So every byte counts. The triegen
+// package automatically chooses the smallest integer values to represent the
+// tables. Compacters allow further compression of the trie by allowing for
+// alternative representations of individual trie blocks.
+//
+// triegen allows generating multiple tries as a single structure. This is
+// useful when, for example, one wants to generate tries for several languages
+// that have a lot of values in common. Some existing libraries for
+// internationalization store all per-language data as a dynamically loadable
+// chunk. The go.text packages are designed with the assumption that the user
+// typically wants to compile in support for all supported languages, in line
+// with the approach common to Go to create a single standalone binary. The
+// multi-root trie approach can give significant storage savings in this
+// scenario.
+//
+// triegen generates both tables and code. The code is optimized to use the
+// automatically chosen data types. The following code is generated for a Trie
+// or multiple Tries named "foo":
+//	- type fooTrie
+//		The trie type.
+//
+//	- func newFooTrie(x int) *fooTrie
+//		Trie constructor, where x is the index of the trie passed to Gen.
+//
+//	- func (t *fooTrie) lookup(s []byte) (v uintX, sz int)
+//		The lookup method, where uintX is automatically chosen.
+//
+//	- func lookupString, lookupUnsafe and lookupStringUnsafe
+//		Variants of the above.
+//
+//	- var fooValues and fooIndex and any tables generated by Compacters.
+//		The core trie data.
+//
+//	- var fooTrieHandles
+//		Indexes of starter blocks in case of multiple trie roots.
+//
+// It is recommended that users test the generated trie by checking the returned
+// value for every rune. Such exhaustive tests are possible as the the number of
+// runes in Unicode is limited.
+package triegen // import "golang.org/x/text/internal/triegen"
+
+// TODO: Arguably, the internally optimized data types would not have to be
+// exposed in the generated API. We could also investigate not generating the
+// code, but using it through a package. We would have to investigate the impact
+// on performance of making such change, though. For packages like unicode/norm,
+// small changes like this could tank performance.
+
+import (
+	"encoding/binary"
+	"fmt"
+	"hash/crc64"
+	"io"
+	"log"
+	"unicode/utf8"
+)
+
+// builder builds a set of tries for associating values with runes. The set of
+// tries can share common index and value blocks.
+type builder struct {
+	Name string
+
+	// ValueType is the type of the trie values looked up.
+	ValueType string
+
+	// ValueSize is the byte size of the ValueType.
+	ValueSize int
+
+	// IndexType is the type of trie index values used for all UTF-8 bytes of
+	// a rune except the last one.
+	IndexType string
+
+	// IndexSize is the byte size of the IndexType.
+	IndexSize int
+
+	// SourceType is used when generating the lookup functions. If the user
+	// requests StringSupport, all lookup functions will be generated for
+	// string input as well.
+	SourceType string
+
+	Trie []*Trie
+
+	IndexBlocks []*node
+	ValueBlocks [][]uint64
+	Compactions []compaction
+	Checksum    uint64
+
+	ASCIIBlock   string
+	StarterBlock string
+
+	indexBlockIdx map[uint64]int
+	valueBlockIdx map[uint64]nodeIndex
+	asciiBlockIdx map[uint64]int
+
+	// Stats are used to fill out the template.
+	Stats struct {
+		NValueEntries int
+		NValueBytes   int
+		NIndexEntries int
+		NIndexBytes   int
+		NHandleBytes  int
+	}
+
+	err error
+}
+
+// A nodeIndex encodes the index of a node, which is defined by the compaction
+// which stores it and an index within the compaction. For internal nodes, the
+// compaction is always 0.
+type nodeIndex struct {
+	compaction int
+	index      int
+}
+
+// compaction keeps track of stats used for the compaction.
+type compaction struct {
+	c         Compacter
+	blocks    []*node
+	maxHandle uint32
+	totalSize int
+
+	// Used by template-based generator and thus exported.
+	Cutoff  uint32
+	Offset  uint32
+	Handler string
+}
+
+func (b *builder) setError(err error) {
+	if b.err == nil {
+		b.err = err
+	}
+}
+
+// An Option can be passed to Gen.
+type Option func(b *builder) error
+
+// Compact configures the trie generator to use the given Compacter.
+func Compact(c Compacter) Option {
+	return func(b *builder) error {
+		b.Compactions = append(b.Compactions, compaction{
+			c:       c,
+			Handler: c.Handler() + "(n, b)"})
+		return nil
+	}
+}
+
+// Gen writes Go code for a shared trie lookup structure to w for the given
+// Tries. The generated trie type will be called nameTrie. newNameTrie(x) will
+// return the *nameTrie for tries[x]. A value can be looked up by using one of
+// the various lookup methods defined on nameTrie. It returns the table size of
+// the generated trie.
+func Gen(w io.Writer, name string, tries []*Trie, opts ...Option) (sz int, err error) {
+	// The index contains two dummy blocks, followed by the zero block. The zero
+	// block is at offset 0x80, so that the offset for the zero block for
+	// continuation bytes is 0.
+	b := &builder{
+		Name:        name,
+		Trie:        tries,
+		IndexBlocks: []*node{{}, {}, {}},
+		Compactions: []compaction{{
+			Handler: name + "Values[n<<6+uint32(b)]",
+		}},
+		// The 0 key in indexBlockIdx and valueBlockIdx is the hash of the zero
+		// block.
+		indexBlockIdx: map[uint64]int{0: 0},
+		valueBlockIdx: map[uint64]nodeIndex{0: {}},
+		asciiBlockIdx: map[uint64]int{},
+	}
+	b.Compactions[0].c = (*simpleCompacter)(b)
+
+	for _, f := range opts {
+		if err := f(b); err != nil {
+			return 0, err
+		}
+	}
+	b.build()
+	if b.err != nil {
+		return 0, b.err
+	}
+	if err = b.print(w); err != nil {
+		return 0, err
+	}
+	return b.Size(), nil
+}
+
+// A Trie represents a single root node of a trie. A builder may build several
+// overlapping tries at once.
+type Trie struct {
+	root *node
+
+	hiddenTrie
+}
+
+// hiddenTrie contains values we want to be visible to the template generator,
+// but hidden from the API documentation.
+type hiddenTrie struct {
+	Name         string
+	Checksum     uint64
+	ASCIIIndex   int
+	StarterIndex int
+}
+
+// NewTrie returns a new trie root.
+func NewTrie(name string) *Trie {
+	return &Trie{
+		&node{
+			children: make([]*node, blockSize),
+			values:   make([]uint64, utf8.RuneSelf),
+		},
+		hiddenTrie{Name: name},
+	}
+}
+
+// Gen is a convenience wrapper around the Gen func passing t as the only trie
+// and uses the name passed to NewTrie. It returns the size of the generated
+// tables.
+func (t *Trie) Gen(w io.Writer, opts ...Option) (sz int, err error) {
+	return Gen(w, t.Name, []*Trie{t}, opts...)
+}
+
+// node is a node of the intermediate trie structure.
+type node struct {
+	// children holds this node's children. It is always of length 64.
+	// A child node may be nil.
+	children []*node
+
+	// values contains the values of this node. If it is non-nil, this node is
+	// either a root or leaf node:
+	// For root nodes, len(values) == 128 and it maps the bytes in [0x00, 0x7F].
+	// For leaf nodes, len(values) ==  64 and it maps the bytes in [0x80, 0xBF].
+	values []uint64
+
+	index nodeIndex
+}
+
+// Insert associates value with the given rune. Insert will panic if a non-zero
+// value is passed for an invalid rune.
+func (t *Trie) Insert(r rune, value uint64) {
+	if value == 0 {
+		return
+	}
+	s := string(r)
+	if []rune(s)[0] != r && value != 0 {
+		// Note: The UCD tables will always assign what amounts to a zero value
+		// to a surrogate. Allowing a zero value for an illegal rune allows
+		// users to iterate over [0..MaxRune] without having to explicitly
+		// exclude surrogates, which would be tedious.
+		panic(fmt.Sprintf("triegen: non-zero value for invalid rune %U", r))
+	}
+	if len(s) == 1 {
+		// It is a root node value (ASCII).
+		t.root.values[s[0]] = value
+		return
+	}
+
+	n := t.root
+	for ; len(s) > 1; s = s[1:] {
+		if n.children == nil {
+			n.children = make([]*node, blockSize)
+		}
+		p := s[0] % blockSize
+		c := n.children[p]
+		if c == nil {
+			c = &node{}
+			n.children[p] = c
+		}
+		if len(s) > 2 && c.values != nil {
+			log.Fatalf("triegen: insert(%U): found internal node with values", r)
+		}
+		n = c
+	}
+	if n.values == nil {
+		n.values = make([]uint64, blockSize)
+	}
+	if n.children != nil {
+		log.Fatalf("triegen: insert(%U): found leaf node that also has child nodes", r)
+	}
+	n.values[s[0]-0x80] = value
+}
+
+// Size returns the number of bytes the generated trie will take to store. It
+// needs to be exported as it is used in the templates.
+func (b *builder) Size() int {
+	// Index blocks.
+	sz := len(b.IndexBlocks) * blockSize * b.IndexSize
+
+	// Skip the first compaction, which represents the normal value blocks, as
+	// its totalSize does not account for the ASCII blocks, which are managed
+	// separately.
+	sz += len(b.ValueBlocks) * blockSize * b.ValueSize
+	for _, c := range b.Compactions[1:] {
+		sz += c.totalSize
+	}
+
+	// TODO: this computation does not account for the fixed overhead of a using
+	// a compaction, either code or data. As for data, though, the typical
+	// overhead of data is in the order of bytes (2 bytes for cases). Further,
+	// the savings of using a compaction should anyway be substantial for it to
+	// be worth it.
+
+	// For multi-root tries, we also need to account for the handles.
+	if len(b.Trie) > 1 {
+		sz += 2 * b.IndexSize * len(b.Trie)
+	}
+	return sz
+}
+
+func (b *builder) build() {
+	// Compute the sizes of the values.
+	var vmax uint64
+	for _, t := range b.Trie {
+		vmax = maxValue(t.root, vmax)
+	}
+	b.ValueType, b.ValueSize = getIntType(vmax)
+
+	// Compute all block allocations.
+	// TODO: first compute the ASCII blocks for all tries and then the other
+	// nodes. ASCII blocks are more restricted in placement, as they require two
+	// blocks to be placed consecutively. Processing them first may improve
+	// sharing (at least one zero block can be expected to be saved.)
+	for _, t := range b.Trie {
+		b.Checksum += b.buildTrie(t)
+	}
+
+	// Compute the offsets for all the Compacters.
+	offset := uint32(0)
+	for i := range b.Compactions {
+		c := &b.Compactions[i]
+		c.Offset = offset
+		offset += c.maxHandle + 1
+		c.Cutoff = offset
+	}
+
+	// Compute the sizes of indexes.
+	// TODO: different byte positions could have different sizes. So far we have
+	// not found a case where this is beneficial.
+	imax := uint64(b.Compactions[len(b.Compactions)-1].Cutoff)
+	for _, ib := range b.IndexBlocks {
+		if x := uint64(ib.index.index); x > imax {
+			imax = x
+		}
+	}
+	b.IndexType, b.IndexSize = getIntType(imax)
+}
+
+func maxValue(n *node, max uint64) uint64 {
+	if n == nil {
+		return max
+	}
+	for _, c := range n.children {
+		max = maxValue(c, max)
+	}
+	for _, v := range n.values {
+		if max < v {
+			max = v
+		}
+	}
+	return max
+}
+
+func getIntType(v uint64) (string, int) {
+	switch {
+	case v < 1<<8:
+		return "uint8", 1
+	case v < 1<<16:
+		return "uint16", 2
+	case v < 1<<32:
+		return "uint32", 4
+	}
+	return "uint64", 8
+}
+
+const (
+	blockSize = 64
+
+	// Subtract two blocks to offset 0x80, the first continuation byte.
+	blockOffset = 2
+
+	// Subtract three blocks to offset 0xC0, the first non-ASCII starter.
+	rootBlockOffset = 3
+)
+
+var crcTable = crc64.MakeTable(crc64.ISO)
+
+func (b *builder) buildTrie(t *Trie) uint64 {
+	n := t.root
+
+	// Get the ASCII offset. For the first trie, the ASCII block will be at
+	// position 0.
+	hasher := crc64.New(crcTable)
+	binary.Write(hasher, binary.BigEndian, n.values)
+	hash := hasher.Sum64()
+
+	v, ok := b.asciiBlockIdx[hash]
+	if !ok {
+		v = len(b.ValueBlocks)
+		b.asciiBlockIdx[hash] = v
+
+		b.ValueBlocks = append(b.ValueBlocks, n.values[:blockSize], n.values[blockSize:])
+		if v == 0 {
+			// Add the zero block at position 2 so that it will be assigned a
+			// zero reference in the lookup blocks.
+			// TODO: always do this? This would allow us to remove a check from
+			// the trie lookup, but at the expense of extra space. Analyze
+			// performance for unicode/norm.
+			b.ValueBlocks = append(b.ValueBlocks, make([]uint64, blockSize))
+		}
+	}
+	t.ASCIIIndex = v
+
+	// Compute remaining offsets.
+	t.Checksum = b.computeOffsets(n, true)
+	// We already subtracted the normal blockOffset from the index. Subtract the
+	// difference for starter bytes.
+	t.StarterIndex = n.index.index - (rootBlockOffset - blockOffset)
+	return t.Checksum
+}
+
+func (b *builder) computeOffsets(n *node, root bool) uint64 {
+	// For the first trie, the root lookup block will be at position 3, which is
+	// the offset for UTF-8 non-ASCII starter bytes.
+	first := len(b.IndexBlocks) == rootBlockOffset
+	if first {
+		b.IndexBlocks = append(b.IndexBlocks, n)
+	}
+
+	// We special-case the cases where all values recursively are 0. This allows
+	// for the use of a zero block to which all such values can be directed.
+	hash := uint64(0)
+	if n.children != nil || n.values != nil {
+		hasher := crc64.New(crcTable)
+		for _, c := range n.children {
+			var v uint64
+			if c != nil {
+				v = b.computeOffsets(c, false)
+			}
+			binary.Write(hasher, binary.BigEndian, v)
+		}
+		binary.Write(hasher, binary.BigEndian, n.values)
+		hash = hasher.Sum64()
+	}
+
+	if first {
+		b.indexBlockIdx[hash] = rootBlockOffset - blockOffset
+	}
+
+	// Compacters don't apply to internal nodes.
+	if n.children != nil {
+		v, ok := b.indexBlockIdx[hash]
+		if !ok {
+			v = len(b.IndexBlocks) - blockOffset
+			b.IndexBlocks = append(b.IndexBlocks, n)
+			b.indexBlockIdx[hash] = v
+		}
+		n.index = nodeIndex{0, v}
+	} else {
+		h, ok := b.valueBlockIdx[hash]
+		if !ok {
+			bestI, bestSize := 0, blockSize*b.ValueSize
+			for i, c := range b.Compactions[1:] {
+				if sz, ok := c.c.Size(n.values); ok && bestSize > sz {
+					bestI, bestSize = i+1, sz
+				}
+			}
+			c := &b.Compactions[bestI]
+			c.totalSize += bestSize
+			v := c.c.Store(n.values)
+			if c.maxHandle < v {
+				c.maxHandle = v
+			}
+			h = nodeIndex{bestI, int(v)}
+			b.valueBlockIdx[hash] = h
+		}
+		n.index = h
+	}
+	return hash
+}

vendor/golang.org/x/text/internal/ucd/ucd.go

@@ -0,0 +1,371 @@
+// Copyright 2014 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package ucd provides a parser for Unicode Character Database files, the
+// format of which is defined in http://www.unicode.org/reports/tr44/. See
+// http://www.unicode.org/Public/UCD/latest/ucd/ for example files.
+//
+// It currently does not support substitutions of missing fields.
+package ucd // import "golang.org/x/text/internal/ucd"
+
+import (
+	"bufio"
+	"errors"
+	"fmt"
+	"io"
+	"log"
+	"regexp"
+	"strconv"
+	"strings"
+)
+
+// UnicodeData.txt fields.
+const (
+	CodePoint = iota
+	Name
+	GeneralCategory
+	CanonicalCombiningClass
+	BidiClass
+	DecompMapping
+	DecimalValue
+	DigitValue
+	NumericValue
+	BidiMirrored
+	Unicode1Name
+	ISOComment
+	SimpleUppercaseMapping
+	SimpleLowercaseMapping
+	SimpleTitlecaseMapping
+)
+
+// Parse calls f for each entry in the given reader of a UCD file. It will close
+// the reader upon return. It will call log.Fatal if any error occurred.
+//
+// This implements the most common usage pattern of using Parser.
+func Parse(r io.ReadCloser, f func(p *Parser)) {
+	defer r.Close()
+
+	p := New(r)
+	for p.Next() {
+		f(p)
+	}
+	if err := p.Err(); err != nil {
+		r.Close() // os.Exit will cause defers not to be called.
+		log.Fatal(err)
+	}
+}
+
+// An Option is used to configure a Parser.
+type Option func(p *Parser)
+
+func keepRanges(p *Parser) {
+	p.keepRanges = true
+}
+
+var (
+	// KeepRanges prevents the expansion of ranges. The raw ranges can be
+	// obtained by calling Range(0) on the parser.
+	KeepRanges Option = keepRanges
+)
+
+// The Part option register a handler for lines starting with a '@'. The text
+// after a '@' is available as the first field. Comments are handled as usual.
+func Part(f func(p *Parser)) Option {
+	return func(p *Parser) {
+		p.partHandler = f
+	}
+}
+
+// The CommentHandler option passes comments that are on a line by itself to
+// a given handler.
+func CommentHandler(f func(s string)) Option {
+	return func(p *Parser) {
+		p.commentHandler = f
+	}
+}
+
+// A Parser parses Unicode Character Database (UCD) files.
+type Parser struct {
+	scanner *bufio.Scanner
+
+	keepRanges bool // Don't expand rune ranges in field 0.
+
+	err     error
+	comment string
+	field   []string
+	// parsedRange is needed in case Range(0) is called more than once for one
+	// field. In some cases this requires scanning ahead.
+	line                 int
+	parsedRange          bool
+	rangeStart, rangeEnd rune
+
+	partHandler    func(p *Parser)
+	commentHandler func(s string)
+}
+
+func (p *Parser) setError(err error, msg string) {
+	if p.err == nil && err != nil {
+		if msg == "" {
+			p.err = fmt.Errorf("ucd:line:%d: %v", p.line, err)
+		} else {
+			p.err = fmt.Errorf("ucd:line:%d:%s: %v", p.line, msg, err)
+		}
+	}
+}
+
+func (p *Parser) getField(i int) string {
+	if i >= len(p.field) {
+		return ""
+	}
+	return p.field[i]
+}
+
+// Err returns a non-nil error if any error occurred during parsing.
+func (p *Parser) Err() error {
+	return p.err
+}
+
+// New returns a Parser for the given Reader.
+func New(r io.Reader, o ...Option) *Parser {
+	p := &Parser{
+		scanner: bufio.NewScanner(r),
+	}
+	for _, f := range o {
+		f(p)
+	}
+	return p
+}
+
+// Next parses the next line in the file. It returns true if a line was parsed
+// and false if it reached the end of the file.
+func (p *Parser) Next() bool {
+	if !p.keepRanges && p.rangeStart < p.rangeEnd {
+		p.rangeStart++
+		return true
+	}
+	p.comment = ""
+	p.field = p.field[:0]
+	p.parsedRange = false
+
+	for p.scanner.Scan() && p.err == nil {
+		p.line++
+		s := p.scanner.Text()
+		if s == "" {
+			continue
+		}
+		if s[0] == '#' {
+			if p.commentHandler != nil {
+				p.commentHandler(strings.TrimSpace(s[1:]))
+			}
+			continue
+		}
+
+		// Parse line
+		if i := strings.IndexByte(s, '#'); i != -1 {
+			p.comment = strings.TrimSpace(s[i+1:])
+			s = s[:i]
+		}
+		if s[0] == '@' {
+			if p.partHandler != nil {
+				p.field = append(p.field, strings.TrimSpace(s[1:]))
+				p.partHandler(p)
+				p.field = p.field[:0]
+			}
+			p.comment = ""
+			continue
+		}
+		for {
+			i := strings.IndexByte(s, ';')
+			if i == -1 {
+				p.field = append(p.field, strings.TrimSpace(s))
+				break
+			}
+			p.field = append(p.field, strings.TrimSpace(s[:i]))
+			s = s[i+1:]
+		}
+		if !p.keepRanges {
+			p.rangeStart, p.rangeEnd = p.getRange(0)
+		}
+		return true
+	}
+	p.setError(p.scanner.Err(), "scanner failed")
+	return false
+}
+
+func parseRune(b string) (rune, error) {
+	if len(b) > 2 && b[0] == 'U' && b[1] == '+' {
+		b = b[2:]
+	}
+	x, err := strconv.ParseUint(b, 16, 32)
+	return rune(x), err
+}
+
+func (p *Parser) parseRune(s string) rune {
+	x, err := parseRune(s)
+	p.setError(err, "failed to parse rune")
+	return x
+}
+
+// Rune parses and returns field i as a rune.
+func (p *Parser) Rune(i int) rune {
+	if i > 0 || p.keepRanges {
+		return p.parseRune(p.getField(i))
+	}
+	return p.rangeStart
+}
+
+// Runes interprets and returns field i as a sequence of runes.
+func (p *Parser) Runes(i int) (runes []rune) {
+	add := func(s string) {
+		if s = strings.TrimSpace(s); len(s) > 0 {
+			runes = append(runes, p.parseRune(s))
+		}
+	}
+	for b := p.getField(i); ; {
+		i := strings.IndexByte(b, ' ')
+		if i == -1 {
+			add(b)
+			break
+		}
+		add(b[:i])
+		b = b[i+1:]
+	}
+	return
+}
+
+var (
+	errIncorrectLegacyRange = errors.New("ucd: unmatched <* First>")
+
+	// reRange matches one line of a legacy rune range.
+	reRange = regexp.MustCompile("^([0-9A-F]*);<([^,]*), ([^>]*)>(.*)$")
+)
+
+// Range parses and returns field i as a rune range. A range is inclusive at
+// both ends. If the field only has one rune, first and last will be identical.
+// It supports the legacy format for ranges used in UnicodeData.txt.
+func (p *Parser) Range(i int) (first, last rune) {
+	if !p.keepRanges {
+		return p.rangeStart, p.rangeStart
+	}
+	return p.getRange(i)
+}
+
+func (p *Parser) getRange(i int) (first, last rune) {
+	b := p.getField(i)
+	if k := strings.Index(b, ".."); k != -1 {
+		return p.parseRune(b[:k]), p.parseRune(b[k+2:])
+	}
+	// The first field may not be a rune, in which case we may ignore any error
+	// and set the range as 0..0.
+	x, err := parseRune(b)
+	if err != nil {
+		// Disable range parsing henceforth. This ensures that an error will be
+		// returned if the user subsequently will try to parse this field as
+		// a Rune.
+		p.keepRanges = true
+	}
+	// Special case for UnicodeData that was retained for backwards compatibility.
+	if i == 0 && len(p.field) > 1 && strings.HasSuffix(p.field[1], "First>") {
+		if p.parsedRange {
+			return p.rangeStart, p.rangeEnd
+		}
+		mf := reRange.FindStringSubmatch(p.scanner.Text())
+		p.line++
+		if mf == nil || !p.scanner.Scan() {
+			p.setError(errIncorrectLegacyRange, "")
+			return x, x
+		}
+		// Using Bytes would be more efficient here, but Text is a lot easier
+		// and this is not a frequent case.
+		ml := reRange.FindStringSubmatch(p.scanner.Text())
+		if ml == nil || mf[2] != ml[2] || ml[3] != "Last" || mf[4] != ml[4] {
+			p.setError(errIncorrectLegacyRange, "")
+			return x, x
+		}
+		p.rangeStart, p.rangeEnd = x, p.parseRune(p.scanner.Text()[:len(ml[1])])
+		p.parsedRange = true
+		return p.rangeStart, p.rangeEnd
+	}
+	return x, x
+}
+
+// bools recognizes all valid UCD boolean values.
+var bools = map[string]bool{
+	"":      false,
+	"N":     false,
+	"No":    false,
+	"F":     false,
+	"False": false,
+	"Y":     true,
+	"Yes":   true,
+	"T":     true,
+	"True":  true,
+}
+
+// Bool parses and returns field i as a boolean value.
+func (p *Parser) Bool(i int) bool {
+	f := p.getField(i)
+	for s, v := range bools {
+		if f == s {
+			return v
+		}
+	}
+	p.setError(strconv.ErrSyntax, "error parsing bool")
+	return false
+}
+
+// Int parses and returns field i as an integer value.
+func (p *Parser) Int(i int) int {
+	x, err := strconv.ParseInt(string(p.getField(i)), 10, 64)
+	p.setError(err, "error parsing int")
+	return int(x)
+}
+
+// Uint parses and returns field i as an unsigned integer value.
+func (p *Parser) Uint(i int) uint {
+	x, err := strconv.ParseUint(string(p.getField(i)), 10, 64)
+	p.setError(err, "error parsing uint")
+	return uint(x)
+}
+
+// Float parses and returns field i as a decimal value.
+func (p *Parser) Float(i int) float64 {
+	x, err := strconv.ParseFloat(string(p.getField(i)), 64)
+	p.setError(err, "error parsing float")
+	return x
+}
+
+// String parses and returns field i as a string value.
+func (p *Parser) String(i int) string {
+	return string(p.getField(i))
+}
+
+// Strings parses and returns field i as a space-separated list of strings.
+func (p *Parser) Strings(i int) []string {
+	ss := strings.Split(string(p.getField(i)), " ")
+	for i, s := range ss {
+		ss[i] = strings.TrimSpace(s)
+	}
+	return ss
+}
+
+// Comment returns the comments for the current line.
+func (p *Parser) Comment() string {
+	return string(p.comment)
+}
+
+var errUndefinedEnum = errors.New("ucd: undefined enum value")
+
+// Enum interprets and returns field i as a value that must be one of the values
+// in enum.
+func (p *Parser) Enum(i int, enum ...string) string {
+	f := p.getField(i)
+	for _, s := range enum {
+		if f == s {
+			return s
+		}
+	}
+	p.setError(errUndefinedEnum, "error parsing enum")
+	return ""
+}

vendor/golang.org/x/text/transform/transform.go

@@ -0,0 +1,705 @@
+// Copyright 2013 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package transform provides reader and writer wrappers that transform the
+// bytes passing through as well as various transformations. Example
+// transformations provided by other packages include normalization and
+// conversion between character sets.
+package transform // import "golang.org/x/text/transform"
+
+import (
+	"bytes"
+	"errors"
+	"io"
+	"unicode/utf8"
+)
+
+var (
+	// ErrShortDst means that the destination buffer was too short to
+	// receive all of the transformed bytes.
+	ErrShortDst = errors.New("transform: short destination buffer")
+
+	// ErrShortSrc means that the source buffer has insufficient data to
+	// complete the transformation.
+	ErrShortSrc = errors.New("transform: short source buffer")
+
+	// ErrEndOfSpan means that the input and output (the transformed input)
+	// are not identical.
+	ErrEndOfSpan = errors.New("transform: input and output are not identical")
+
+	// errInconsistentByteCount means that Transform returned success (nil
+	// error) but also returned nSrc inconsistent with the src argument.
+	errInconsistentByteCount = errors.New("transform: inconsistent byte count returned")
+
+	// errShortInternal means that an internal buffer is not large enough
+	// to make progress and the Transform operation must be aborted.
+	errShortInternal = errors.New("transform: short internal buffer")
+)
+
+// Transformer transforms bytes.
+type Transformer interface {
+	// Transform writes to dst the transformed bytes read from src, and
+	// returns the number of dst bytes written and src bytes read. The
+	// atEOF argument tells whether src represents the last bytes of the
+	// input.
+	//
+	// Callers should always process the nDst bytes produced and account
+	// for the nSrc bytes consumed before considering the error err.
+	//
+	// A nil error means that all of the transformed bytes (whether freshly
+	// transformed from src or left over from previous Transform calls)
+	// were written to dst. A nil error can be returned regardless of
+	// whether atEOF is true. If err is nil then nSrc must equal len(src);
+	// the converse is not necessarily true.
+	//
+	// ErrShortDst means that dst was too short to receive all of the
+	// transformed bytes. ErrShortSrc means that src had insufficient data
+	// to complete the transformation. If both conditions apply, then
+	// either error may be returned. Other than the error conditions listed
+	// here, implementations are free to report other errors that arise.
+	Transform(dst, src []byte, atEOF bool) (nDst, nSrc int, err error)
+
+	// Reset resets the state and allows a Transformer to be reused.
+	Reset()
+}
+
+// SpanningTransformer extends the Transformer interface with a Span method
+// that determines how much of the input already conforms to the Transformer.
+type SpanningTransformer interface {
+	Transformer
+
+	// Span returns a position in src such that transforming src[:n] results in
+	// identical output src[:n] for these bytes. It does not necessarily return
+	// the largest such n. The atEOF argument tells whether src represents the
+	// last bytes of the input.
+	//
+	// Callers should always account for the n bytes consumed before
+	// considering the error err.
+	//
+	// A nil error means that all input bytes are known to be identical to the
+	// output produced by the Transformer. A nil error can be be returned
+	// regardless of whether atEOF is true. If err is nil, then then n must
+	// equal len(src); the converse is not necessarily true.
+	//
+	// ErrEndOfSpan means that the Transformer output may differ from the
+	// input after n bytes. Note that n may be len(src), meaning that the output
+	// would contain additional bytes after otherwise identical output.
+	// ErrShortSrc means that src had insufficient data to determine whether the
+	// remaining bytes would change. Other than the error conditions listed
+	// here, implementations are free to report other errors that arise.
+	//
+	// Calling Span can modify the Transformer state as a side effect. In
+	// effect, it does the transformation just as calling Transform would, only
+	// without copying to a destination buffer and only up to a point it can
+	// determine the input and output bytes are the same. This is obviously more
+	// limited than calling Transform, but can be more efficient in terms of
+	// copying and allocating buffers. Calls to Span and Transform may be
+	// interleaved.
+	Span(src []byte, atEOF bool) (n int, err error)
+}
+
+// NopResetter can be embedded by implementations of Transformer to add a nop
+// Reset method.
+type NopResetter struct{}
+
+// Reset implements the Reset method of the Transformer interface.
+func (NopResetter) Reset() {}
+
+// Reader wraps another io.Reader by transforming the bytes read.
+type Reader struct {
+	r   io.Reader
+	t   Transformer
+	err error
+
+	// dst[dst0:dst1] contains bytes that have been transformed by t but
+	// not yet copied out via Read.
+	dst        []byte
+	dst0, dst1 int
+
+	// src[src0:src1] contains bytes that have been read from r but not
+	// yet transformed through t.
+	src        []byte
+	src0, src1 int
+
+	// transformComplete is whether the transformation is complete,
+	// regardless of whether or not it was successful.
+	transformComplete bool
+}
+
+const defaultBufSize = 4096
+
+// NewReader returns a new Reader that wraps r by transforming the bytes read
+// via t. It calls Reset on t.
+func NewReader(r io.Reader, t Transformer) *Reader {
+	t.Reset()
+	return &Reader{
+		r:   r,
+		t:   t,
+		dst: make([]byte, defaultBufSize),
+		src: make([]byte, defaultBufSize),
+	}
+}
+
+// Read implements the io.Reader interface.
+func (r *Reader) Read(p []byte) (int, error) {
+	n, err := 0, error(nil)
+	for {
+		// Copy out any transformed bytes and return the final error if we are done.
+		if r.dst0 != r.dst1 {
+			n = copy(p, r.dst[r.dst0:r.dst1])
+			r.dst0 += n
+			if r.dst0 == r.dst1 && r.transformComplete {
+				return n, r.err
+			}
+			return n, nil
+		} else if r.transformComplete {
+			return 0, r.err
+		}
+
+		// Try to transform some source bytes, or to flush the transformer if we
+		// are out of source bytes. We do this even if r.r.Read returned an error.
+		// As the io.Reader documentation says, "process the n > 0 bytes returned
+		// before considering the error".
+		if r.src0 != r.src1 || r.err != nil {
+			r.dst0 = 0
+			r.dst1, n, err = r.t.Transform(r.dst, r.src[r.src0:r.src1], r.err == io.EOF)
+			r.src0 += n
+
+			switch {
+			case err == nil:
+				if r.src0 != r.src1 {
+					r.err = errInconsistentByteCount
+				}
+				// The Transform call was successful; we are complete if we
+				// cannot read more bytes into src.
+				r.transformComplete = r.err != nil
+				continue
+			case err == ErrShortDst && (r.dst1 != 0 || n != 0):
+				// Make room in dst by copying out, and try again.
+				continue
+			case err == ErrShortSrc && r.src1-r.src0 != len(r.src) && r.err == nil:
+				// Read more bytes into src via the code below, and try again.
+			default:
+				r.transformComplete = true
+				// The reader error (r.err) takes precedence over the
+				// transformer error (err) unless r.err is nil or io.EOF.
+				if r.err == nil || r.err == io.EOF {
+					r.err = err
+				}
+				continue
+			}
+		}
+
+		// Move any untransformed source bytes to the start of the buffer
+		// and read more bytes.
+		if r.src0 != 0 {
+			r.src0, r.src1 = 0, copy(r.src, r.src[r.src0:r.src1])
+		}
+		n, r.err = r.r.Read(r.src[r.src1:])
+		r.src1 += n
+	}
+}
+
+// TODO: implement ReadByte (and ReadRune??).
+
+// Writer wraps another io.Writer by transforming the bytes read.
+// The user needs to call Close to flush unwritten bytes that may
+// be buffered.
+type Writer struct {
+	w   io.Writer
+	t   Transformer
+	dst []byte
+
+	// src[:n] contains bytes that have not yet passed through t.
+	src []byte
+	n   int
+}
+
+// NewWriter returns a new Writer that wraps w by transforming the bytes written
+// via t. It calls Reset on t.
+func NewWriter(w io.Writer, t Transformer) *Writer {
+	t.Reset()
+	return &Writer{
+		w:   w,
+		t:   t,
+		dst: make([]byte, defaultBufSize),
+		src: make([]byte, defaultBufSize),
+	}
+}
+
+// Write implements the io.Writer interface. If there are not enough
+// bytes available to complete a Transform, the bytes will be buffered
+// for the next write. Call Close to convert the remaining bytes.
+func (w *Writer) Write(data []byte) (n int, err error) {
+	src := data
+	if w.n > 0 {
+		// Append bytes from data to the last remainder.
+		// TODO: limit the amount copied on first try.
+		n = copy(w.src[w.n:], data)
+		w.n += n
+		src = w.src[:w.n]
+	}
+	for {
+		nDst, nSrc, err := w.t.Transform(w.dst, src, false)
+		if _, werr := w.w.Write(w.dst[:nDst]); werr != nil {
+			return n, werr
+		}
+		src = src[nSrc:]
+		if w.n == 0 {
+			n += nSrc
+		} else if len(src) <= n {
+			// Enough bytes from w.src have been consumed. We make src point
+			// to data instead to reduce the copying.
+			w.n = 0
+			n -= len(src)
+			src = data[n:]
+			if n < len(data) && (err == nil || err == ErrShortSrc) {
+				continue
+			}
+		}
+		switch err {
+		case ErrShortDst:
+			// This error is okay as long as we are making progress.
+			if nDst > 0 || nSrc > 0 {
+				continue
+			}
+		case ErrShortSrc:
+			if len(src) < len(w.src) {
+				m := copy(w.src, src)
+				// If w.n > 0, bytes from data were already copied to w.src and n
+				// was already set to the number of bytes consumed.
+				if w.n == 0 {
+					n += m
+				}
+				w.n = m
+				err = nil
+			} else if nDst > 0 || nSrc > 0 {
+				// Not enough buffer to store the remainder. Keep processing as
+				// long as there is progress. Without this case, transforms that
+				// require a lookahead larger than the buffer may result in an
+				// error. This is not something one may expect to be common in
+				// practice, but it may occur when buffers are set to small
+				// sizes during testing.
+				continue
+			}
+		case nil:
+			if w.n > 0 {
+				err = errInconsistentByteCount
+			}
+		}
+		return n, err
+	}
+}
+
+// Close implements the io.Closer interface.
+func (w *Writer) Close() error {
+	src := w.src[:w.n]
+	for {
+		nDst, nSrc, err := w.t.Transform(w.dst, src, true)
+		if _, werr := w.w.Write(w.dst[:nDst]); werr != nil {
+			return werr
+		}
+		if err != ErrShortDst {
+			return err
+		}
+		src = src[nSrc:]
+	}
+}
+
+type nop struct{ NopResetter }
+
+func (nop) Transform(dst, src []byte, atEOF bool) (nDst, nSrc int, err error) {
+	n := copy(dst, src)
+	if n < len(src) {
+		err = ErrShortDst
+	}
+	return n, n, err
+}
+
+func (nop) Span(src []byte, atEOF bool) (n int, err error) {
+	return len(src), nil
+}
+
+type discard struct{ NopResetter }
+
+func (discard) Transform(dst, src []byte, atEOF bool) (nDst, nSrc int, err error) {
+	return 0, len(src), nil
+}
+
+var (
+	// Discard is a Transformer for which all Transform calls succeed
+	// by consuming all bytes and writing nothing.
+	Discard Transformer = discard{}
+
+	// Nop is a SpanningTransformer that copies src to dst.
+	Nop SpanningTransformer = nop{}
+)
+
+// chain is a sequence of links. A chain with N Transformers has N+1 links and
+// N+1 buffers. Of those N+1 buffers, the first and last are the src and dst
+// buffers given to chain.Transform and the middle N-1 buffers are intermediate
+// buffers owned by the chain. The i'th link transforms bytes from the i'th
+// buffer chain.link[i].b at read offset chain.link[i].p to the i+1'th buffer
+// chain.link[i+1].b at write offset chain.link[i+1].n, for i in [0, N).
+type chain struct {
+	link []link
+	err  error
+	// errStart is the index at which the error occurred plus 1. Processing
+	// errStart at this level at the next call to Transform. As long as
+	// errStart > 0, chain will not consume any more source bytes.
+	errStart int
+}
+
+func (c *chain) fatalError(errIndex int, err error) {
+	if i := errIndex + 1; i > c.errStart {
+		c.errStart = i
+		c.err = err
+	}
+}
+
+type link struct {
+	t Transformer
+	// b[p:n] holds the bytes to be transformed by t.
+	b []byte
+	p int
+	n int
+}
+
+func (l *link) src() []byte {
+	return l.b[l.p:l.n]
+}
+
+func (l *link) dst() []byte {
+	return l.b[l.n:]
+}
+
+// Chain returns a Transformer that applies t in sequence.
+func Chain(t ...Transformer) Transformer {
+	if len(t) == 0 {
+		return nop{}
+	}
+	c := &chain{link: make([]link, len(t)+1)}
+	for i, tt := range t {
+		c.link[i].t = tt
+	}
+	// Allocate intermediate buffers.
+	b := make([][defaultBufSize]byte, len(t)-1)
+	for i := range b {
+		c.link[i+1].b = b[i][:]
+	}
+	return c
+}
+
+// Reset resets the state of Chain. It calls Reset on all the Transformers.
+func (c *chain) Reset() {
+	for i, l := range c.link {
+		if l.t != nil {
+			l.t.Reset()
+		}
+		c.link[i].p, c.link[i].n = 0, 0
+	}
+}
+
+// TODO: make chain use Span (is going to be fun to implement!)
+
+// Transform applies the transformers of c in sequence.
+func (c *chain) Transform(dst, src []byte, atEOF bool) (nDst, nSrc int, err error) {
+	// Set up src and dst in the chain.
+	srcL := &c.link[0]
+	dstL := &c.link[len(c.link)-1]
+	srcL.b, srcL.p, srcL.n = src, 0, len(src)
+	dstL.b, dstL.n = dst, 0
+	var lastFull, needProgress bool // for detecting progress
+
+	// i is the index of the next Transformer to apply, for i in [low, high].
+	// low is the lowest index for which c.link[low] may still produce bytes.
+	// high is the highest index for which c.link[high] has a Transformer.
+	// The error returned by Transform determines whether to increase or
+	// decrease i. We try to completely fill a buffer before converting it.
+	for low, i, high := c.errStart, c.errStart, len(c.link)-2; low <= i && i <= high; {
+		in, out := &c.link[i], &c.link[i+1]
+		nDst, nSrc, err0 := in.t.Transform(out.dst(), in.src(), atEOF && low == i)
+		out.n += nDst
+		in.p += nSrc
+		if i > 0 && in.p == in.n {
+			in.p, in.n = 0, 0
+		}
+		needProgress, lastFull = lastFull, false
+		switch err0 {
+		case ErrShortDst:
+			// Process the destination buffer next. Return if we are already
+			// at the high index.
+			if i == high {
+				return dstL.n, srcL.p, ErrShortDst
+			}
+			if out.n != 0 {
+				i++
+				// If the Transformer at the next index is not able to process any
+				// source bytes there is nothing that can be done to make progress
+				// and the bytes will remain unprocessed. lastFull is used to
+				// detect this and break out of the loop with a fatal error.
+				lastFull = true
+				continue
+			}
+			// The destination buffer was too small, but is completely empty.
+			// Return a fatal error as this transformation can never complete.
+			c.fatalError(i, errShortInternal)
+		case ErrShortSrc:
+			if i == 0 {
+				// Save ErrShortSrc in err. All other errors take precedence.
+				err = ErrShortSrc
+				break
+			}
+			// Source bytes were depleted before filling up the destination buffer.
+			// Verify we made some progress, move the remaining bytes to the errStart
+			// and try to get more source bytes.
+			if needProgress && nSrc == 0 || in.n-in.p == len(in.b) {
+				// There were not enough source bytes to proceed while the source
+				// buffer cannot hold any more bytes. Return a fatal error as this
+				// transformation can never complete.
+				c.fatalError(i, errShortInternal)
+				break
+			}
+			// in.b is an internal buffer and we can make progress.
+			in.p, in.n = 0, copy(in.b, in.src())
+			fallthrough
+		case nil:
+			// if i == low, we have depleted the bytes at index i or any lower levels.
+			// In that case we increase low and i. In all other cases we decrease i to
+			// fetch more bytes before proceeding to the next index.
+			if i > low {
+				i--
+				continue
+			}
+		default:
+			c.fatalError(i, err0)
+		}
+		// Exhausted level low or fatal error: increase low and continue
+		// to process the bytes accepted so far.
+		i++
+		low = i
+	}
+
+	// If c.errStart > 0, this means we found a fatal error.  We will clear
+	// all upstream buffers. At this point, no more progress can be made
+	// downstream, as Transform would have bailed while handling ErrShortDst.
+	if c.errStart > 0 {
+		for i := 1; i < c.errStart; i++ {
+			c.link[i].p, c.link[i].n = 0, 0
+		}
+		err, c.errStart, c.err = c.err, 0, nil
+	}
+	return dstL.n, srcL.p, err
+}
+
+// Deprecated: use runes.Remove instead.
+func RemoveFunc(f func(r rune) bool) Transformer {
+	return removeF(f)
+}
+
+type removeF func(r rune) bool
+
+func (removeF) Reset() {}
+
+// Transform implements the Transformer interface.
+func (t removeF) Transform(dst, src []byte, atEOF bool) (nDst, nSrc int, err error) {
+	for r, sz := rune(0), 0; len(src) > 0; src = src[sz:] {
+
+		if r = rune(src[0]); r < utf8.RuneSelf {
+			sz = 1
+		} else {
+			r, sz = utf8.DecodeRune(src)
+
+			if sz == 1 {
+				// Invalid rune.
+				if !atEOF && !utf8.FullRune(src) {
+					err = ErrShortSrc
+					break
+				}
+				// We replace illegal bytes with RuneError. Not doing so might
+				// otherwise turn a sequence of invalid UTF-8 into valid UTF-8.
+				// The resulting byte sequence may subsequently contain runes
+				// for which t(r) is true that were passed unnoticed.
+				if !t(r) {
+					if nDst+3 > len(dst) {
+						err = ErrShortDst
+						break
+					}
+					nDst += copy(dst[nDst:], "\uFFFD")
+				}
+				nSrc++
+				continue
+			}
+		}
+
+		if !t(r) {
+			if nDst+sz > len(dst) {
+				err = ErrShortDst
+				break
+			}
+			nDst += copy(dst[nDst:], src[:sz])
+		}
+		nSrc += sz
+	}
+	return
+}
+
+// grow returns a new []byte that is longer than b, and copies the first n bytes
+// of b to the start of the new slice.
+func grow(b []byte, n int) []byte {
+	m := len(b)
+	if m <= 32 {
+		m = 64
+	} else if m <= 256 {
+		m *= 2
+	} else {
+		m += m >> 1
+	}
+	buf := make([]byte, m)
+	copy(buf, b[:n])
+	return buf
+}
+
+const initialBufSize = 128
+
+// String returns a string with the result of converting s[:n] using t, where
+// n <= len(s). If err == nil, n will be len(s). It calls Reset on t.
+func String(t Transformer, s string) (result string, n int, err error) {
+	t.Reset()
+	if s == "" {
+		// Fast path for the common case for empty input. Results in about a
+		// 86% reduction of running time for BenchmarkStringLowerEmpty.
+		if _, _, err := t.Transform(nil, nil, true); err == nil {
+			return "", 0, nil
+		}
+	}
+
+	// Allocate only once. Note that both dst and src escape when passed to
+	// Transform.
+	buf := [2 * initialBufSize]byte{}
+	dst := buf[:initialBufSize:initialBufSize]
+	src := buf[initialBufSize : 2*initialBufSize]
+
+	// The input string s is transformed in multiple chunks (starting with a
+	// chunk size of initialBufSize). nDst and nSrc are per-chunk (or
+	// per-Transform-call) indexes, pDst and pSrc are overall indexes.
+	nDst, nSrc := 0, 0
+	pDst, pSrc := 0, 0
+
+	// pPrefix is the length of a common prefix: the first pPrefix bytes of the
+	// result will equal the first pPrefix bytes of s. It is not guaranteed to
+	// be the largest such value, but if pPrefix, len(result) and len(s) are
+	// all equal after the final transform (i.e. calling Transform with atEOF
+	// being true returned nil error) then we don't need to allocate a new
+	// result string.
+	pPrefix := 0
+	for {
+		// Invariant: pDst == pPrefix && pSrc == pPrefix.
+
+		n := copy(src, s[pSrc:])
+		nDst, nSrc, err = t.Transform(dst, src[:n], pSrc+n == len(s))
+		pDst += nDst
+		pSrc += nSrc
+
+		// TODO:  let transformers implement an optional Spanner interface, akin
+		// to norm's QuickSpan. This would even allow us to avoid any allocation.
+		if !bytes.Equal(dst[:nDst], src[:nSrc]) {
+			break
+		}
+		pPrefix = pSrc
+		if err == ErrShortDst {
+			// A buffer can only be short if a transformer modifies its input.
+			break
+		} else if err == ErrShortSrc {
+			if nSrc == 0 {
+				// No progress was made.
+				break
+			}
+			// Equal so far and !atEOF, so continue checking.
+		} else if err != nil || pPrefix == len(s) {
+			return string(s[:pPrefix]), pPrefix, err
+		}
+	}
+	// Post-condition: pDst == pPrefix + nDst && pSrc == pPrefix + nSrc.
+
+	// We have transformed the first pSrc bytes of the input s to become pDst
+	// transformed bytes. Those transformed bytes are discontiguous: the first
+	// pPrefix of them equal s[:pPrefix] and the last nDst of them equal
+	// dst[:nDst]. We copy them around, into a new dst buffer if necessary, so
+	// that they become one contiguous slice: dst[:pDst].
+	if pPrefix != 0 {
+		newDst := dst
+		if pDst > len(newDst) {
+			newDst = make([]byte, len(s)+nDst-nSrc)
+		}
+		copy(newDst[pPrefix:pDst], dst[:nDst])
+		copy(newDst[:pPrefix], s[:pPrefix])
+		dst = newDst
+	}
+
+	// Prevent duplicate Transform calls with atEOF being true at the end of
+	// the input. Also return if we have an unrecoverable error.
+	if (err == nil && pSrc == len(s)) ||
+		(err != nil && err != ErrShortDst && err != ErrShortSrc) {
+		return string(dst[:pDst]), pSrc, err
+	}
+
+	// Transform the remaining input, growing dst and src buffers as necessary.
+	for {
+		n := copy(src, s[pSrc:])
+		nDst, nSrc, err := t.Transform(dst[pDst:], src[:n], pSrc+n == len(s))
+		pDst += nDst
+		pSrc += nSrc
+
+		// If we got ErrShortDst or ErrShortSrc, do not grow as long as we can
+		// make progress. This may avoid excessive allocations.
+		if err == ErrShortDst {
+			if nDst == 0 {
+				dst = grow(dst, pDst)
+			}
+		} else if err == ErrShortSrc {
+			if nSrc == 0 {
+				src = grow(src, 0)
+			}
+		} else if err != nil || pSrc == len(s) {
+			return string(dst[:pDst]), pSrc, err
+		}
+	}
+}
+
+// Bytes returns a new byte slice with the result of converting b[:n] using t,
+// where n <= len(b). If err == nil, n will be len(b). It calls Reset on t.
+func Bytes(t Transformer, b []byte) (result []byte, n int, err error) {
+	return doAppend(t, 0, make([]byte, len(b)), b)
+}
+
+// Append appends the result of converting src[:n] using t to dst, where
+// n <= len(src), If err == nil, n will be len(src). It calls Reset on t.
+func Append(t Transformer, dst, src []byte) (result []byte, n int, err error) {
+	if len(dst) == cap(dst) {
+		n := len(src) + len(dst) // It is okay for this to be 0.
+		b := make([]byte, n)
+		dst = b[:copy(b, dst)]
+	}
+	return doAppend(t, len(dst), dst[:cap(dst)], src)
+}
+
+func doAppend(t Transformer, pDst int, dst, src []byte) (result []byte, n int, err error) {
+	t.Reset()
+	pSrc := 0
+	for {
+		nDst, nSrc, err := t.Transform(dst[pDst:], src[pSrc:], true)
+		pDst += nDst
+		pSrc += nSrc
+		if err != ErrShortDst {
+			return dst[:pDst], pSrc, err
+		}
+
+		// Grow the destination buffer, but do not grow as long as we can make
+		// progress. This may avoid excessive allocations.
+		if nDst == 0 {
+			dst = grow(dst, pDst)
+		}
+	}
+}

vendor/golang.org/x/text/unicode/cldr/base.go

@@ -0,0 +1,105 @@
+// Copyright 2013 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package cldr
+
+import (
+	"encoding/xml"
+	"regexp"
+	"strconv"
+)
+
+// Elem is implemented by every XML element.
+type Elem interface {
+	setEnclosing(Elem)
+	setName(string)
+	enclosing() Elem
+
+	GetCommon() *Common
+}
+
+type hidden struct {
+	CharData string `xml:",chardata"`
+	Alias    *struct {
+		Common
+		Source string `xml:"source,attr"`
+		Path   string `xml:"path,attr"`
+	} `xml:"alias"`
+	Def *struct {
+		Common
+		Choice string `xml:"choice,attr,omitempty"`
+		Type   string `xml:"type,attr,omitempty"`
+	} `xml:"default"`
+}
+
+// Common holds several of the most common attributes and sub elements
+// of an XML element.
+type Common struct {
+	XMLName         xml.Name
+	name            string
+	enclElem        Elem
+	Type            string `xml:"type,attr,omitempty"`
+	Reference       string `xml:"reference,attr,omitempty"`
+	Alt             string `xml:"alt,attr,omitempty"`
+	ValidSubLocales string `xml:"validSubLocales,attr,omitempty"`
+	Draft           string `xml:"draft,attr,omitempty"`
+	hidden
+}
+
+// Default returns the default type to select from the enclosed list
+// or "" if no default value is specified.
+func (e *Common) Default() string {
+	if e.Def == nil {
+		return ""
+	}
+	if e.Def.Choice != "" {
+		return e.Def.Choice
+	} else if e.Def.Type != "" {
+		// Type is still used by the default element in collation.
+		return e.Def.Type
+	}
+	return ""
+}
+
+// Element returns the XML element name.
+func (e *Common) Element() string {
+	return e.name
+}
+
+// GetCommon returns e. It is provided such that Common implements Elem.
+func (e *Common) GetCommon() *Common {
+	return e
+}
+
+// Data returns the character data accumulated for this element.
+func (e *Common) Data() string {
+	e.CharData = charRe.ReplaceAllStringFunc(e.CharData, replaceUnicode)
+	return e.CharData
+}
+
+func (e *Common) setName(s string) {
+	e.name = s
+}
+
+func (e *Common) enclosing() Elem {
+	return e.enclElem
+}
+
+func (e *Common) setEnclosing(en Elem) {
+	e.enclElem = en
+}
+
+// Escape characters that can be escaped without further escaping the string.
+var charRe = regexp.MustCompile(`&#x[0-9a-fA-F]*;|\\u[0-9a-fA-F]{4}|\\U[0-9a-fA-F]{8}|\\x[0-9a-fA-F]{2}|\\[0-7]{3}|\\[abtnvfr]`)
+
+// replaceUnicode converts hexadecimal Unicode codepoint notations to a one-rune string.
+// It assumes the input string is correctly formatted.
+func replaceUnicode(s string) string {
+	if s[1] == '#' {
+		r, _ := strconv.ParseInt(s[3:len(s)-1], 16, 32)
+		return string(r)
+	}
+	r, _, _, _ := strconv.UnquoteChar(s, 0)
+	return string(r)
+}

vendor/golang.org/x/text/unicode/cldr/cldr.go

@@ -0,0 +1,130 @@
+// Copyright 2013 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:generate go run makexml.go -output xml.go
+
+// Package cldr provides a parser for LDML and related XML formats.
+// This package is intended to be used by the table generation tools
+// for the various internationalization-related packages.
+// As the XML types are generated from the CLDR DTD, and as the CLDR standard
+// is periodically amended, this package may change considerably over time.
+// This mostly means that data may appear and disappear between versions.
+// That is, old code should keep compiling for newer versions, but data
+// may have moved or changed.
+// CLDR version 22 is the first version supported by this package.
+// Older versions may not work.
+package cldr // import "golang.org/x/text/unicode/cldr"
+
+import (
+	"fmt"
+	"sort"
+)
+
+// CLDR provides access to parsed data of the Unicode Common Locale Data Repository.
+type CLDR struct {
+	parent   map[string][]string
+	locale   map[string]*LDML
+	resolved map[string]*LDML
+	bcp47    *LDMLBCP47
+	supp     *SupplementalData
+}
+
+func makeCLDR() *CLDR {
+	return &CLDR{
+		parent:   make(map[string][]string),
+		locale:   make(map[string]*LDML),
+		resolved: make(map[string]*LDML),
+		bcp47:    &LDMLBCP47{},
+		supp:     &SupplementalData{},
+	}
+}
+
+// BCP47 returns the parsed BCP47 LDML data. If no such data was parsed, nil is returned.
+func (cldr *CLDR) BCP47() *LDMLBCP47 {
+	return nil
+}
+
+// Draft indicates the draft level of an element.
+type Draft int
+
+const (
+	Approved Draft = iota
+	Contributed
+	Provisional
+	Unconfirmed
+)
+
+var drafts = []string{"unconfirmed", "provisional", "contributed", "approved", ""}
+
+// ParseDraft returns the Draft value corresponding to the given string. The
+// empty string corresponds to Approved.
+func ParseDraft(level string) (Draft, error) {
+	if level == "" {
+		return Approved, nil
+	}
+	for i, s := range drafts {
+		if level == s {
+			return Unconfirmed - Draft(i), nil
+		}
+	}
+	return Approved, fmt.Errorf("cldr: unknown draft level %q", level)
+}
+
+func (d Draft) String() string {
+	return drafts[len(drafts)-1-int(d)]
+}
+
+// SetDraftLevel sets which draft levels to include in the evaluated LDML.
+// Any draft element for which the draft level is higher than lev will be excluded.
+// If multiple draft levels are available for a single element, the one with the
+// lowest draft level will be selected, unless preferDraft is true, in which case
+// the highest draft will be chosen.
+// It is assumed that the underlying LDML is canonicalized.
+func (cldr *CLDR) SetDraftLevel(lev Draft, preferDraft bool) {
+	// TODO: implement
+	cldr.resolved = make(map[string]*LDML)
+}
+
+// RawLDML returns the LDML XML for id in unresolved form.
+// id must be one of the strings returned by Locales.
+func (cldr *CLDR) RawLDML(loc string) *LDML {
+	return cldr.locale[loc]
+}
+
+// LDML returns the fully resolved LDML XML for loc, which must be one of
+// the strings returned by Locales.
+func (cldr *CLDR) LDML(loc string) (*LDML, error) {
+	return cldr.resolve(loc)
+}
+
+// Supplemental returns the parsed supplemental data. If no such data was parsed,
+// nil is returned.
+func (cldr *CLDR) Supplemental() *SupplementalData {
+	return cldr.supp
+}
+
+// Locales returns the locales for which there exist files.
+// Valid sublocales for which there is no file are not included.
+// The root locale is always sorted first.
+func (cldr *CLDR) Locales() []string {
+	loc := []string{"root"}
+	hasRoot := false
+	for l, _ := range cldr.locale {
+		if l == "root" {
+			hasRoot = true
+			continue
+		}
+		loc = append(loc, l)
+	}
+	sort.Strings(loc[1:])
+	if !hasRoot {
+		return loc[1:]
+	}
+	return loc
+}
+
+// Get fills in the fields of x based on the XPath path.
+func Get(e Elem, path string) (res Elem, err error) {
+	return walkXPath(e, path)
+}

vendor/golang.org/x/text/unicode/cldr/collate.go

@@ -0,0 +1,359 @@
+// Copyright 2013 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package cldr
+
+import (
+	"bufio"
+	"encoding/xml"
+	"errors"
+	"fmt"
+	"strconv"
+	"strings"
+	"unicode"
+	"unicode/utf8"
+)
+
+// RuleProcessor can be passed to Collator's Process method, which
+// parses the rules and calls the respective method for each rule found.
+type RuleProcessor interface {
+	Reset(anchor string, before int) error
+	Insert(level int, str, context, extend string) error
+	Index(id string)
+}
+
+const (
+	// cldrIndex is a Unicode-reserved sentinel value used to mark the start
+	// of a grouping within an index.
+	// We ignore any rule that starts with this rune.
+	// See http://unicode.org/reports/tr35/#Collation_Elements for details.
+	cldrIndex = "\uFDD0"
+
+	// specialAnchor is the format in which to represent logical reset positions,
+	// such as "first tertiary ignorable".
+	specialAnchor = "<%s/>"
+)
+
+// Process parses the rules for the tailorings of this collation
+// and calls the respective methods of p for each rule found.
+func (c Collation) Process(p RuleProcessor) (err error) {
+	if len(c.Cr) > 0 {
+		if len(c.Cr) > 1 {
+			return fmt.Errorf("multiple cr elements, want 0 or 1")
+		}
+		return processRules(p, c.Cr[0].Data())
+	}
+	if c.Rules.Any != nil {
+		return c.processXML(p)
+	}
+	return errors.New("no tailoring data")
+}
+
+// processRules parses rules in the Collation Rule Syntax defined in
+// http://www.unicode.org/reports/tr35/tr35-collation.html#Collation_Tailorings.
+func processRules(p RuleProcessor, s string) (err error) {
+	chk := func(s string, e error) string {
+		if err == nil {
+			err = e
+		}
+		return s
+	}
+	i := 0 // Save the line number for use after the loop.
+	scanner := bufio.NewScanner(strings.NewReader(s))
+	for ; scanner.Scan() && err == nil; i++ {
+		for s := skipSpace(scanner.Text()); s != "" && s[0] != '#'; s = skipSpace(s) {
+			level := 5
+			var ch byte
+			switch ch, s = s[0], s[1:]; ch {
+			case '&': // followed by <anchor> or '[' <key> ']'
+				if s = skipSpace(s); consume(&s, '[') {
+					s = chk(parseSpecialAnchor(p, s))
+				} else {
+					s = chk(parseAnchor(p, 0, s))
+				}
+			case '<': // sort relation '<'{1,4}, optionally followed by '*'.
+				for level = 1; consume(&s, '<'); level++ {
+				}
+				if level > 4 {
+					err = fmt.Errorf("level %d > 4", level)
+				}
+				fallthrough
+			case '=': // identity relation, optionally followed by *.
+				if consume(&s, '*') {
+					s = chk(parseSequence(p, level, s))
+				} else {
+					s = chk(parseOrder(p, level, s))
+				}
+			default:
+				chk("", fmt.Errorf("illegal operator %q", ch))
+				break
+			}
+		}
+	}
+	if chk("", scanner.Err()); err != nil {
+		return fmt.Errorf("%d: %v", i, err)
+	}
+	return nil
+}
+
+// parseSpecialAnchor parses the anchor syntax which is either of the form
+//    ['before' <level>] <anchor>
+// or
+//    [<label>]
+// The starting should already be consumed.
+func parseSpecialAnchor(p RuleProcessor, s string) (tail string, err error) {
+	i := strings.IndexByte(s, ']')
+	if i == -1 {
+		return "", errors.New("unmatched bracket")
+	}
+	a := strings.TrimSpace(s[:i])
+	s = s[i+1:]
+	if strings.HasPrefix(a, "before ") {
+		l, err := strconv.ParseUint(skipSpace(a[len("before "):]), 10, 3)
+		if err != nil {
+			return s, err
+		}
+		return parseAnchor(p, int(l), s)
+	}
+	return s, p.Reset(fmt.Sprintf(specialAnchor, a), 0)
+}
+
+func parseAnchor(p RuleProcessor, level int, s string) (tail string, err error) {
+	anchor, s, err := scanString(s)
+	if err != nil {
+		return s, err
+	}
+	return s, p.Reset(anchor, level)
+}
+
+func parseOrder(p RuleProcessor, level int, s string) (tail string, err error) {
+	var value, context, extend string
+	if value, s, err = scanString(s); err != nil {
+		return s, err
+	}
+	if strings.HasPrefix(value, cldrIndex) {
+		p.Index(value[len(cldrIndex):])
+		return
+	}
+	if consume(&s, '|') {
+		if context, s, err = scanString(s); err != nil {
+			return s, errors.New("missing string after context")
+		}
+	}
+	if consume(&s, '/') {
+		if extend, s, err = scanString(s); err != nil {
+			return s, errors.New("missing string after extension")
+		}
+	}
+	return s, p.Insert(level, value, context, extend)
+}
+
+// scanString scans a single input string.
+func scanString(s string) (str, tail string, err error) {
+	if s = skipSpace(s); s == "" {
+		return s, s, errors.New("missing string")
+	}
+	buf := [16]byte{} // small but enough to hold most cases.
+	value := buf[:0]
+	for s != "" {
+		if consume(&s, '\'') {
+			i := strings.IndexByte(s, '\'')
+			if i == -1 {
+				return "", "", errors.New(`unmatched single quote`)
+			}
+			if i == 0 {
+				value = append(value, '\'')
+			} else {
+				value = append(value, s[:i]...)
+			}
+			s = s[i+1:]
+			continue
+		}
+		r, sz := utf8.DecodeRuneInString(s)
+		if unicode.IsSpace(r) || strings.ContainsRune("&<=#", r) {
+			break
+		}
+		value = append(value, s[:sz]...)
+		s = s[sz:]
+	}
+	return string(value), skipSpace(s), nil
+}
+
+func parseSequence(p RuleProcessor, level int, s string) (tail string, err error) {
+	if s = skipSpace(s); s == "" {
+		return s, errors.New("empty sequence")
+	}
+	last := rune(0)
+	for s != "" {
+		r, sz := utf8.DecodeRuneInString(s)
+		s = s[sz:]
+
+		if r == '-' {
+			// We have a range. The first element was already written.
+			if last == 0 {
+				return s, errors.New("range without starter value")
+			}
+			r, sz = utf8.DecodeRuneInString(s)
+			s = s[sz:]
+			if r == utf8.RuneError || r < last {
+				return s, fmt.Errorf("invalid range %q-%q", last, r)
+			}
+			for i := last + 1; i <= r; i++ {
+				if err := p.Insert(level, string(i), "", ""); err != nil {
+					return s, err
+				}
+			}
+			last = 0
+			continue
+		}
+
+		if unicode.IsSpace(r) || unicode.IsPunct(r) {
+			break
+		}
+
+		// normal case
+		if err := p.Insert(level, string(r), "", ""); err != nil {
+			return s, err
+		}
+		last = r
+	}
+	return s, nil
+}
+
+func skipSpace(s string) string {
+	return strings.TrimLeftFunc(s, unicode.IsSpace)
+}
+
+// consumes returns whether the next byte is ch. If so, it gobbles it by
+// updating s.
+func consume(s *string, ch byte) (ok bool) {
+	if *s == "" || (*s)[0] != ch {
+		return false
+	}
+	*s = (*s)[1:]
+	return true
+}
+
+// The following code parses Collation rules of CLDR version 24 and before.
+
+var lmap = map[byte]int{
+	'p': 1,
+	's': 2,
+	't': 3,
+	'i': 5,
+}
+
+type rulesElem struct {
+	Rules struct {
+		Common
+		Any []*struct {
+			XMLName xml.Name
+			rule
+		} `xml:",any"`
+	} `xml:"rules"`
+}
+
+type rule struct {
+	Value  string `xml:",chardata"`
+	Before string `xml:"before,attr"`
+	Any    []*struct {
+		XMLName xml.Name
+		rule
+	} `xml:",any"`
+}
+
+var emptyValueError = errors.New("cldr: empty rule value")
+
+func (r *rule) value() (string, error) {
+	// Convert hexadecimal Unicode codepoint notation to a string.
+	s := charRe.ReplaceAllStringFunc(r.Value, replaceUnicode)
+	r.Value = s
+	if s == "" {
+		if len(r.Any) != 1 {
+			return "", emptyValueError
+		}
+		r.Value = fmt.Sprintf(specialAnchor, r.Any[0].XMLName.Local)
+		r.Any = nil
+	} else if len(r.Any) != 0 {
+		return "", fmt.Errorf("cldr: XML elements found in collation rule: %v", r.Any)
+	}
+	return r.Value, nil
+}
+
+func (r rule) process(p RuleProcessor, name, context, extend string) error {
+	v, err := r.value()
+	if err != nil {
+		return err
+	}
+	switch name {
+	case "p", "s", "t", "i":
+		if strings.HasPrefix(v, cldrIndex) {
+			p.Index(v[len(cldrIndex):])
+			return nil
+		}
+		if err := p.Insert(lmap[name[0]], v, context, extend); err != nil {
+			return err
+		}
+	case "pc", "sc", "tc", "ic":
+		level := lmap[name[0]]
+		for _, s := range v {
+			if err := p.Insert(level, string(s), context, extend); err != nil {
+				return err
+			}
+		}
+	default:
+		return fmt.Errorf("cldr: unsupported tag: %q", name)
+	}
+	return nil
+}
+
+// processXML parses the format of CLDR versions 24 and older.
+func (c Collation) processXML(p RuleProcessor) (err error) {
+	// Collation is generated and defined in xml.go.
+	var v string
+	for _, r := range c.Rules.Any {
+		switch r.XMLName.Local {
+		case "reset":
+			level := 0
+			switch r.Before {
+			case "primary", "1":
+				level = 1
+			case "secondary", "2":
+				level = 2
+			case "tertiary", "3":
+				level = 3
+			case "":
+			default:
+				return fmt.Errorf("cldr: unknown level %q", r.Before)
+			}
+			v, err = r.value()
+			if err == nil {
+				err = p.Reset(v, level)
+			}
+		case "x":
+			var context, extend string
+			for _, r1 := range r.Any {
+				v, err = r1.value()
+				switch r1.XMLName.Local {
+				case "context":
+					context = v
+				case "extend":
+					extend = v
+				}
+			}
+			for _, r1 := range r.Any {
+				if t := r1.XMLName.Local; t == "context" || t == "extend" {
+					continue
+				}
+				r1.rule.process(p, r1.XMLName.Local, context, extend)
+			}
+		default:
+			err = r.rule.process(p, r.XMLName.Local, "", "")
+		}
+		if err != nil {
+			return err
+		}
+	}
+	return nil
+}

vendor/golang.org/x/text/unicode/cldr/decode.go

@@ -0,0 +1,171 @@
+// Copyright 2013 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package cldr
+
+import (
+	"archive/zip"
+	"bytes"
+	"encoding/xml"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"log"
+	"os"
+	"path/filepath"
+	"regexp"
+)
+
+// A Decoder loads an archive of CLDR data.
+type Decoder struct {
+	dirFilter     []string
+	sectionFilter []string
+	loader        Loader
+	cldr          *CLDR
+	curLocale     string
+}
+
+// SetSectionFilter takes a list top-level LDML element names to which
+// evaluation of LDML should be limited.  It automatically calls SetDirFilter.
+func (d *Decoder) SetSectionFilter(filter ...string) {
+	d.sectionFilter = filter
+	// TODO: automatically set dir filter
+}
+
+// SetDirFilter limits the loading of LDML XML files of the specied directories.
+// Note that sections may be split across directories differently for different CLDR versions.
+// For more robust code, use SetSectionFilter.
+func (d *Decoder) SetDirFilter(dir ...string) {
+	d.dirFilter = dir
+}
+
+// A Loader provides access to the files of a CLDR archive.
+type Loader interface {
+	Len() int
+	Path(i int) string
+	Reader(i int) (io.ReadCloser, error)
+}
+
+var fileRe = regexp.MustCompile(`.*[/\\](.*)[/\\](.*)\.xml`)
+
+// Decode loads and decodes the files represented by l.
+func (d *Decoder) Decode(l Loader) (cldr *CLDR, err error) {
+	d.cldr = makeCLDR()
+	for i := 0; i < l.Len(); i++ {
+		fname := l.Path(i)
+		if m := fileRe.FindStringSubmatch(fname); m != nil {
+			if len(d.dirFilter) > 0 && !in(d.dirFilter, m[1]) {
+				continue
+			}
+			var r io.Reader
+			if r, err = l.Reader(i); err == nil {
+				err = d.decode(m[1], m[2], r)
+			}
+			if err != nil {
+				return nil, err
+			}
+		}
+	}
+	d.cldr.finalize(d.sectionFilter)
+	return d.cldr, nil
+}
+
+func (d *Decoder) decode(dir, id string, r io.Reader) error {
+	var v interface{}
+	var l *LDML
+	cldr := d.cldr
+	switch {
+	case dir == "supplemental":
+		v = cldr.supp
+	case dir == "transforms":
+		return nil
+	case dir == "bcp47":
+		v = cldr.bcp47
+	case dir == "validity":
+		return nil
+	default:
+		ok := false
+		if v, ok = cldr.locale[id]; !ok {
+			l = &LDML{}
+			v, cldr.locale[id] = l, l
+		}
+	}
+	x := xml.NewDecoder(r)
+	if err := x.Decode(v); err != nil {
+		log.Printf("%s/%s: %v", dir, id, err)
+		return err
+	}
+	if l != nil {
+		if l.Identity == nil {
+			return fmt.Errorf("%s/%s: missing identity element", dir, id)
+		}
+		// TODO: verify when CLDR bug http://unicode.org/cldr/trac/ticket/8970
+		// is resolved.
+		// path := strings.Split(id, "_")
+		// if lang := l.Identity.Language.Type; lang != path[0] {
+		// 	return fmt.Errorf("%s/%s: language was %s; want %s", dir, id, lang, path[0])
+		// }
+	}
+	return nil
+}
+
+type pathLoader []string
+
+func makePathLoader(path string) (pl pathLoader, err error) {
+	err = filepath.Walk(path, func(path string, _ os.FileInfo, err error) error {
+		pl = append(pl, path)
+		return err
+	})
+	return pl, err
+}
+
+func (pl pathLoader) Len() int {
+	return len(pl)
+}
+
+func (pl pathLoader) Path(i int) string {
+	return pl[i]
+}
+
+func (pl pathLoader) Reader(i int) (io.ReadCloser, error) {
+	return os.Open(pl[i])
+}
+
+// DecodePath loads CLDR data from the given path.
+func (d *Decoder) DecodePath(path string) (cldr *CLDR, err error) {
+	loader, err := makePathLoader(path)
+	if err != nil {
+		return nil, err
+	}
+	return d.Decode(loader)
+}
+
+type zipLoader struct {
+	r *zip.Reader
+}
+
+func (zl zipLoader) Len() int {
+	return len(zl.r.File)
+}
+
+func (zl zipLoader) Path(i int) string {
+	return zl.r.File[i].Name
+}
+
+func (zl zipLoader) Reader(i int) (io.ReadCloser, error) {
+	return zl.r.File[i].Open()
+}
+
+// DecodeZip loads CLDR data from the zip archive for which r is the source.
+func (d *Decoder) DecodeZip(r io.Reader) (cldr *CLDR, err error) {
+	buffer, err := ioutil.ReadAll(r)
+	if err != nil {
+		return nil, err
+	}
+	archive, err := zip.NewReader(bytes.NewReader(buffer), int64(len(buffer)))
+	if err != nil {
+		return nil, err
+	}
+	return d.Decode(zipLoader{archive})
+}

vendor/golang.org/x/text/unicode/cldr/makexml.go

@@ -0,0 +1,400 @@
+// Copyright 2013 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// +build ignore
+
+// This tool generates types for the various XML formats of CLDR.
+package main
+
+import (
+	"archive/zip"
+	"bytes"
+	"encoding/xml"
+	"flag"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"log"
+	"os"
+	"regexp"
+	"strings"
+
+	"golang.org/x/text/internal/gen"
+)
+
+var outputFile = flag.String("output", "xml.go", "output file name")
+
+func main() {
+	flag.Parse()
+
+	r := gen.OpenCLDRCoreZip()
+	buffer, err := ioutil.ReadAll(r)
+	if err != nil {
+		log.Fatal("Could not read zip file")
+	}
+	r.Close()
+	z, err := zip.NewReader(bytes.NewReader(buffer), int64(len(buffer)))
+	if err != nil {
+		log.Fatalf("Could not read zip archive: %v", err)
+	}
+
+	var buf bytes.Buffer
+
+	version := gen.CLDRVersion()
+
+	for _, dtd := range files {
+		for _, f := range z.File {
+			if strings.HasSuffix(f.Name, dtd.file+".dtd") {
+				r, err := f.Open()
+				failOnError(err)
+
+				b := makeBuilder(&buf, dtd)
+				b.parseDTD(r)
+				b.resolve(b.index[dtd.top[0]])
+				b.write()
+				if b.version != "" && version != b.version {
+					println(f.Name)
+					log.Fatalf("main: inconsistent versions: found %s; want %s", b.version, version)
+				}
+				break
+			}
+		}
+	}
+	fmt.Fprintln(&buf, "// Version is the version of CLDR from which the XML definitions are generated.")
+	fmt.Fprintf(&buf, "const Version = %q\n", version)
+
+	gen.WriteGoFile(*outputFile, "cldr", buf.Bytes())
+}
+
+func failOnError(err error) {
+	if err != nil {
+		log.New(os.Stderr, "", log.Lshortfile).Output(2, err.Error())
+		os.Exit(1)
+	}
+}
+
+// configuration data per DTD type
+type dtd struct {
+	file string   // base file name
+	root string   // Go name of the root XML element
+	top  []string // create a different type for this section
+
+	skipElem    []string // hard-coded or deprecated elements
+	skipAttr    []string // attributes to exclude
+	predefined  []string // hard-coded elements exist of the form <name>Elem
+	forceRepeat []string // elements to make slices despite DTD
+}
+
+var files = []dtd{
+	{
+		file: "ldmlBCP47",
+		root: "LDMLBCP47",
+		top:  []string{"ldmlBCP47"},
+		skipElem: []string{
+			"cldrVersion", // deprecated, not used
+		},
+	},
+	{
+		file: "ldmlSupplemental",
+		root: "SupplementalData",
+		top:  []string{"supplementalData"},
+		skipElem: []string{
+			"cldrVersion", // deprecated, not used
+		},
+		forceRepeat: []string{
+			"plurals", // data defined in plurals.xml and ordinals.xml
+		},
+	},
+	{
+		file: "ldml",
+		root: "LDML",
+		top: []string{
+			"ldml", "collation", "calendar", "timeZoneNames", "localeDisplayNames", "numbers",
+		},
+		skipElem: []string{
+			"cp",       // not used anywhere
+			"special",  // not used anywhere
+			"fallback", // deprecated, not used
+			"alias",    // in Common
+			"default",  // in Common
+		},
+		skipAttr: []string{
+			"hiraganaQuarternary", // typo in DTD, correct version included as well
+		},
+		predefined: []string{"rules"},
+	},
+}
+
+var comments = map[string]string{
+	"ldmlBCP47": `
+// LDMLBCP47 holds information on allowable values for various variables in LDML.
+`,
+	"supplementalData": `
+// SupplementalData holds information relevant for internationalization
+// and proper use of CLDR, but that is not contained in the locale hierarchy.
+`,
+	"ldml": `
+// LDML is the top-level type for locale-specific data.
+`,
+	"collation": `
+// Collation contains rules that specify a certain sort-order,
+// as a tailoring of the root order. 
+// The parsed rules are obtained by passing a RuleProcessor to Collation's
+// Process method.
+`,
+	"calendar": `
+// Calendar specifies the fields used for formatting and parsing dates and times.
+// The month and quarter names are identified numerically, starting at 1.
+// The day (of the week) names are identified with short strings, since there is
+// no universally-accepted numeric designation.
+`,
+	"dates": `
+// Dates contains information regarding the format and parsing of dates and times.
+`,
+	"localeDisplayNames": `
+// LocaleDisplayNames specifies localized display names for for scripts, languages,
+// countries, currencies, and variants.
+`,
+	"numbers": `
+// Numbers supplies information for formatting and parsing numbers and currencies.
+`,
+}
+
+type element struct {
+	name      string // XML element name
+	category  string // elements contained by this element
+	signature string // category + attrKey*
+
+	attr []*attribute // attributes supported by this element.
+	sub  []struct {   // parsed and evaluated sub elements of this element.
+		e      *element
+		repeat bool // true if the element needs to be a slice
+	}
+
+	resolved bool // prevent multiple resolutions of this element.
+}
+
+type attribute struct {
+	name string
+	key  string
+	list []string
+
+	tag string // Go tag
+}
+
+var (
+	reHead  = regexp.MustCompile(` *(\w+) +([\w\-]+)`)
+	reAttr  = regexp.MustCompile(` *(\w+) *(?:(\w+)|\(([\w\- \|]+)\)) *(?:#([A-Z]*) *(?:\"([\.\d+])\")?)? *("[\w\-:]*")?`)
+	reElem  = regexp.MustCompile(`^ *(EMPTY|ANY|\(.*\)[\*\+\?]?) *$`)
+	reToken = regexp.MustCompile(`\w\-`)
+)
+
+// builder is used to read in the DTD files from CLDR and generate Go code
+// to be used with the encoding/xml package.
+type builder struct {
+	w       io.Writer
+	index   map[string]*element
+	elem    []*element
+	info    dtd
+	version string
+}
+
+func makeBuilder(w io.Writer, d dtd) builder {
+	return builder{
+		w:     w,
+		index: make(map[string]*element),
+		elem:  []*element{},
+		info:  d,
+	}
+}
+
+// parseDTD parses a DTD file.
+func (b *builder) parseDTD(r io.Reader) {
+	for d := xml.NewDecoder(r); ; {
+		t, err := d.Token()
+		if t == nil {
+			break
+		}
+		failOnError(err)
+		dir, ok := t.(xml.Directive)
+		if !ok {
+			continue
+		}
+		m := reHead.FindSubmatch(dir)
+		dir = dir[len(m[0]):]
+		ename := string(m[2])
+		el, elementFound := b.index[ename]
+		switch string(m[1]) {
+		case "ELEMENT":
+			if elementFound {
+				log.Fatal("parseDTD: duplicate entry for element %q", ename)
+			}
+			m := reElem.FindSubmatch(dir)
+			if m == nil {
+				log.Fatalf("parseDTD: invalid element %q", string(dir))
+			}
+			if len(m[0]) != len(dir) {
+				log.Fatal("parseDTD: invalid element %q", string(dir), len(dir), len(m[0]), string(m[0]))
+			}
+			s := string(m[1])
+			el = &element{
+				name:     ename,
+				category: s,
+			}
+			b.index[ename] = el
+		case "ATTLIST":
+			if !elementFound {
+				log.Fatalf("parseDTD: unknown element %q", ename)
+			}
+			s := string(dir)
+			m := reAttr.FindStringSubmatch(s)
+			if m == nil {
+				log.Fatal(fmt.Errorf("parseDTD: invalid attribute %q", string(dir)))
+			}
+			if m[4] == "FIXED" {
+				b.version = m[5]
+			} else {
+				switch m[1] {
+				case "draft", "references", "alt", "validSubLocales", "standard" /* in Common */ :
+				case "type", "choice":
+				default:
+					el.attr = append(el.attr, &attribute{
+						name: m[1],
+						key:  s,
+						list: reToken.FindAllString(m[3], -1),
+					})
+					el.signature = fmt.Sprintf("%s=%s+%s", el.signature, m[1], m[2])
+				}
+			}
+		}
+	}
+}
+
+var reCat = regexp.MustCompile(`[ ,\|]*(?:(\(|\)|\#?[\w_-]+)([\*\+\?]?))?`)
+
+// resolve takes a parsed element and converts it into structured data
+// that can be used to generate the XML code.
+func (b *builder) resolve(e *element) {
+	if e.resolved {
+		return
+	}
+	b.elem = append(b.elem, e)
+	e.resolved = true
+	s := e.category
+	found := make(map[string]bool)
+	sequenceStart := []int{}
+	for len(s) > 0 {
+		m := reCat.FindStringSubmatch(s)
+		if m == nil {
+			log.Fatalf("%s: invalid category string %q", e.name, s)
+		}
+		repeat := m[2] == "*" || m[2] == "+" || in(b.info.forceRepeat, m[1])
+		switch m[1] {
+		case "":
+		case "(":
+			sequenceStart = append(sequenceStart, len(e.sub))
+		case ")":
+			if len(sequenceStart) == 0 {
+				log.Fatalf("%s: unmatched closing parenthesis", e.name)
+			}
+			for i := sequenceStart[len(sequenceStart)-1]; i < len(e.sub); i++ {
+				e.sub[i].repeat = e.sub[i].repeat || repeat
+			}
+			sequenceStart = sequenceStart[:len(sequenceStart)-1]
+		default:
+			if in(b.info.skipElem, m[1]) {
+			} else if sub, ok := b.index[m[1]]; ok {
+				if !found[sub.name] {
+					e.sub = append(e.sub, struct {
+						e      *element
+						repeat bool
+					}{sub, repeat})
+					found[sub.name] = true
+					b.resolve(sub)
+				}
+			} else if m[1] == "#PCDATA" || m[1] == "ANY" {
+			} else if m[1] != "EMPTY" {
+				log.Fatalf("resolve:%s: element %q not found", e.name, m[1])
+			}
+		}
+		s = s[len(m[0]):]
+	}
+}
+
+// return true if s is contained in set.
+func in(set []string, s string) bool {
+	for _, v := range set {
+		if v == s {
+			return true
+		}
+	}
+	return false
+}
+
+var repl = strings.NewReplacer("-", " ", "_", " ")
+
+// title puts the first character or each character following '_' in title case and
+// removes all occurrences of '_'.
+func title(s string) string {
+	return strings.Replace(strings.Title(repl.Replace(s)), " ", "", -1)
+}
+
+// writeElem generates Go code for a single element, recursively.
+func (b *builder) writeElem(tab int, e *element) {
+	p := func(f string, x ...interface{}) {
+		f = strings.Replace(f, "\n", "\n"+strings.Repeat("\t", tab), -1)
+		fmt.Fprintf(b.w, f, x...)
+	}
+	if len(e.sub) == 0 && len(e.attr) == 0 {
+		p("Common")
+		return
+	}
+	p("struct {")
+	tab++
+	p("\nCommon")
+	for _, attr := range e.attr {
+		if !in(b.info.skipAttr, attr.name) {
+			p("\n%s string `xml:\"%s,attr\"`", title(attr.name), attr.name)
+		}
+	}
+	for _, sub := range e.sub {
+		if in(b.info.predefined, sub.e.name) {
+			p("\n%sElem", sub.e.name)
+			continue
+		}
+		if in(b.info.skipElem, sub.e.name) {
+			continue
+		}
+		p("\n%s ", title(sub.e.name))
+		if sub.repeat {
+			p("[]")
+		}
+		p("*")
+		if in(b.info.top, sub.e.name) {
+			p(title(sub.e.name))
+		} else {
+			b.writeElem(tab, sub.e)
+		}
+		p(" `xml:\"%s\"`", sub.e.name)
+	}
+	tab--
+	p("\n}")
+}
+
+// write generates the Go XML code.
+func (b *builder) write() {
+	for i, name := range b.info.top {
+		e := b.index[name]
+		if e != nil {
+			fmt.Fprintf(b.w, comments[name])
+			name := title(e.name)
+			if i == 0 {
+				name = b.info.root
+			}
+			fmt.Fprintf(b.w, "type %s ", name)
+			b.writeElem(0, e)
+			fmt.Fprint(b.w, "\n")
+		}
+	}
+}

vendor/golang.org/x/text/unicode/cldr/resolve.go

@@ -0,0 +1,602 @@
+// Copyright 2013 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package cldr
+
+// This file implements the various inheritance constructs defined by LDML.
+// See http://www.unicode.org/reports/tr35/#Inheritance_and_Validity
+// for more details.
+
+import (
+	"fmt"
+	"log"
+	"reflect"
+	"regexp"
+	"sort"
+	"strings"
+)
+
+// fieldIter iterates over fields in a struct. It includes
+// fields of embedded structs.
+type fieldIter struct {
+	v        reflect.Value
+	index, n []int
+}
+
+func iter(v reflect.Value) fieldIter {
+	if v.Kind() != reflect.Struct {
+		log.Panicf("value %v must be a struct", v)
+	}
+	i := fieldIter{
+		v:     v,
+		index: []int{0},
+		n:     []int{v.NumField()},
+	}
+	i.descent()
+	return i
+}
+
+func (i *fieldIter) descent() {
+	for f := i.field(); f.Anonymous && f.Type.NumField() > 0; f = i.field() {
+		i.index = append(i.index, 0)
+		i.n = append(i.n, f.Type.NumField())
+	}
+}
+
+func (i *fieldIter) done() bool {
+	return len(i.index) == 1 && i.index[0] >= i.n[0]
+}
+
+func skip(f reflect.StructField) bool {
+	return !f.Anonymous && (f.Name[0] < 'A' || f.Name[0] > 'Z')
+}
+
+func (i *fieldIter) next() {
+	for {
+		k := len(i.index) - 1
+		i.index[k]++
+		if i.index[k] < i.n[k] {
+			if !skip(i.field()) {
+				break
+			}
+		} else {
+			if k == 0 {
+				return
+			}
+			i.index = i.index[:k]
+			i.n = i.n[:k]
+		}
+	}
+	i.descent()
+}
+
+func (i *fieldIter) value() reflect.Value {
+	return i.v.FieldByIndex(i.index)
+}
+
+func (i *fieldIter) field() reflect.StructField {
+	return i.v.Type().FieldByIndex(i.index)
+}
+
+type visitor func(v reflect.Value) error
+
+var stopDescent = fmt.Errorf("do not recurse")
+
+func (f visitor) visit(x interface{}) error {
+	return f.visitRec(reflect.ValueOf(x))
+}
+
+// visit recursively calls f on all nodes in v.
+func (f visitor) visitRec(v reflect.Value) error {
+	if v.Kind() == reflect.Ptr {
+		if v.IsNil() {
+			return nil
+		}
+		return f.visitRec(v.Elem())
+	}
+	if err := f(v); err != nil {
+		if err == stopDescent {
+			return nil
+		}
+		return err
+	}
+	switch v.Kind() {
+	case reflect.Struct:
+		for i := iter(v); !i.done(); i.next() {
+			if err := f.visitRec(i.value()); err != nil {
+				return err
+			}
+		}
+	case reflect.Slice:
+		for i := 0; i < v.Len(); i++ {
+			if err := f.visitRec(v.Index(i)); err != nil {
+				return err
+			}
+		}
+	}
+	return nil
+}
+
+// getPath is used for error reporting purposes only.
+func getPath(e Elem) string {
+	if e == nil {
+		return "<nil>"
+	}
+	if e.enclosing() == nil {
+		return e.GetCommon().name
+	}
+	if e.GetCommon().Type == "" {
+		return fmt.Sprintf("%s.%s", getPath(e.enclosing()), e.GetCommon().name)
+	}
+	return fmt.Sprintf("%s.%s[type=%s]", getPath(e.enclosing()), e.GetCommon().name, e.GetCommon().Type)
+}
+
+// xmlName returns the xml name of the element or attribute
+func xmlName(f reflect.StructField) (name string, attr bool) {
+	tags := strings.Split(f.Tag.Get("xml"), ",")
+	for _, s := range tags {
+		attr = attr || s == "attr"
+	}
+	return tags[0], attr
+}
+
+func findField(v reflect.Value, key string) (reflect.Value, error) {
+	v = reflect.Indirect(v)
+	for i := iter(v); !i.done(); i.next() {
+		if n, _ := xmlName(i.field()); n == key {
+			return i.value(), nil
+		}
+	}
+	return reflect.Value{}, fmt.Errorf("cldr: no field %q in element %#v", key, v.Interface())
+}
+
+var xpathPart = regexp.MustCompile(`(\pL+)(?:\[@(\pL+)='([\w-]+)'\])?`)
+
+func walkXPath(e Elem, path string) (res Elem, err error) {
+	for _, c := range strings.Split(path, "/") {
+		if c == ".." {
+			if e = e.enclosing(); e == nil {
+				panic("path ..")
+				return nil, fmt.Errorf(`cldr: ".." moves past root in path %q`, path)
+			}
+			continue
+		} else if c == "" {
+			continue
+		}
+		m := xpathPart.FindStringSubmatch(c)
+		if len(m) == 0 || len(m[0]) != len(c) {
+			return nil, fmt.Errorf("cldr: syntax error in path component %q", c)
+		}
+		v, err := findField(reflect.ValueOf(e), m[1])
+		if err != nil {
+			return nil, err
+		}
+		switch v.Kind() {
+		case reflect.Slice:
+			i := 0
+			if m[2] != "" || v.Len() > 1 {
+				if m[2] == "" {
+					m[2] = "type"
+					if m[3] = e.GetCommon().Default(); m[3] == "" {
+						return nil, fmt.Errorf("cldr: type selector or default value needed for element %s", m[1])
+					}
+				}
+				for ; i < v.Len(); i++ {
+					vi := v.Index(i)
+					key, err := findField(vi.Elem(), m[2])
+					if err != nil {
+						return nil, err
+					}
+					key = reflect.Indirect(key)
+					if key.Kind() == reflect.String && key.String() == m[3] {
+						break
+					}
+				}
+			}
+			if i == v.Len() || v.Index(i).IsNil() {
+				return nil, fmt.Errorf("no %s found with %s==%s", m[1], m[2], m[3])
+			}
+			e = v.Index(i).Interface().(Elem)
+		case reflect.Ptr:
+			if v.IsNil() {
+				return nil, fmt.Errorf("cldr: element %q not found within element %q", m[1], e.GetCommon().name)
+			}
+			var ok bool
+			if e, ok = v.Interface().(Elem); !ok {
+				return nil, fmt.Errorf("cldr: %q is not an XML element", m[1])
+			} else if m[2] != "" || m[3] != "" {
+				return nil, fmt.Errorf("cldr: no type selector allowed for element %s", m[1])
+			}
+		default:
+			return nil, fmt.Errorf("cldr: %q is not an XML element", m[1])
+		}
+	}
+	return e, nil
+}
+
+const absPrefix = "//ldml/"
+
+func (cldr *CLDR) resolveAlias(e Elem, src, path string) (res Elem, err error) {
+	if src != "locale" {
+		if !strings.HasPrefix(path, absPrefix) {
+			return nil, fmt.Errorf("cldr: expected absolute path, found %q", path)
+		}
+		path = path[len(absPrefix):]
+		if e, err = cldr.resolve(src); err != nil {
+			return nil, err
+		}
+	}
+	return walkXPath(e, path)
+}
+
+func (cldr *CLDR) resolveAndMergeAlias(e Elem) error {
+	alias := e.GetCommon().Alias
+	if alias == nil {
+		return nil
+	}
+	a, err := cldr.resolveAlias(e, alias.Source, alias.Path)
+	if err != nil {
+		return fmt.Errorf("%v: error evaluating path %q: %v", getPath(e), alias.Path, err)
+	}
+	// Ensure alias node was already evaluated. TODO: avoid double evaluation.
+	err = cldr.resolveAndMergeAlias(a)
+	v := reflect.ValueOf(e).Elem()
+	for i := iter(reflect.ValueOf(a).Elem()); !i.done(); i.next() {
+		if vv := i.value(); vv.Kind() != reflect.Ptr || !vv.IsNil() {
+			if _, attr := xmlName(i.field()); !attr {
+				v.FieldByIndex(i.index).Set(vv)
+			}
+		}
+	}
+	return err
+}
+
+func (cldr *CLDR) aliasResolver() visitor {
+	return func(v reflect.Value) (err error) {
+		if e, ok := v.Addr().Interface().(Elem); ok {
+			err = cldr.resolveAndMergeAlias(e)
+			if err == nil && blocking[e.GetCommon().name] {
+				return stopDescent
+			}
+		}
+		return err
+	}
+}
+
+// elements within blocking elements do not inherit.
+// Taken from CLDR's supplementalMetaData.xml.
+var blocking = map[string]bool{
+	"identity":         true,
+	"supplementalData": true,
+	"cldrTest":         true,
+	"collation":        true,
+	"transform":        true,
+}
+
+// Distinguishing attributes affect inheritance; two elements with different
+// distinguishing attributes are treated as different for purposes of inheritance,
+// except when such attributes occur in the indicated elements.
+// Taken from CLDR's supplementalMetaData.xml.
+var distinguishing = map[string][]string{
+	"key":        nil,
+	"request_id": nil,
+	"id":         nil,
+	"registry":   nil,
+	"alt":        nil,
+	"iso4217":    nil,
+	"iso3166":    nil,
+	"mzone":      nil,
+	"from":       nil,
+	"to":         nil,
+	"type": []string{
+		"abbreviationFallback",
+		"default",
+		"mapping",
+		"measurementSystem",
+		"preferenceOrdering",
+	},
+	"numberSystem": nil,
+}
+
+func in(set []string, s string) bool {
+	for _, v := range set {
+		if v == s {
+			return true
+		}
+	}
+	return false
+}
+
+// attrKey computes a key based on the distinguishable attributes of
+// an element and it's values.
+func attrKey(v reflect.Value, exclude ...string) string {
+	parts := []string{}
+	ename := v.Interface().(Elem).GetCommon().name
+	v = v.Elem()
+	for i := iter(v); !i.done(); i.next() {
+		if name, attr := xmlName(i.field()); attr {
+			if except, ok := distinguishing[name]; ok && !in(exclude, name) && !in(except, ename) {
+				v := i.value()
+				if v.Kind() == reflect.Ptr {
+					v = v.Elem()
+				}
+				if v.IsValid() {
+					parts = append(parts, fmt.Sprintf("%s=%s", name, v.String()))
+				}
+			}
+		}
+	}
+	sort.Strings(parts)
+	return strings.Join(parts, ";")
+}
+
+// Key returns a key for e derived from all distinguishing attributes
+// except those specified by exclude.
+func Key(e Elem, exclude ...string) string {
+	return attrKey(reflect.ValueOf(e), exclude...)
+}
+
+// linkEnclosing sets the enclosing element as well as the name
+// for all sub-elements of child, recursively.
+func linkEnclosing(parent, child Elem) {
+	child.setEnclosing(parent)
+	v := reflect.ValueOf(child).Elem()
+	for i := iter(v); !i.done(); i.next() {
+		vf := i.value()
+		if vf.Kind() == reflect.Slice {
+			for j := 0; j < vf.Len(); j++ {
+				linkEnclosing(child, vf.Index(j).Interface().(Elem))
+			}
+		} else if vf.Kind() == reflect.Ptr && !vf.IsNil() && vf.Elem().Kind() == reflect.Struct {
+			linkEnclosing(child, vf.Interface().(Elem))
+		}
+	}
+}
+
+func setNames(e Elem, name string) {
+	e.setName(name)
+	v := reflect.ValueOf(e).Elem()
+	for i := iter(v); !i.done(); i.next() {
+		vf := i.value()
+		name, _ = xmlName(i.field())
+		if vf.Kind() == reflect.Slice {
+			for j := 0; j < vf.Len(); j++ {
+				setNames(vf.Index(j).Interface().(Elem), name)
+			}
+		} else if vf.Kind() == reflect.Ptr && !vf.IsNil() && vf.Elem().Kind() == reflect.Struct {
+			setNames(vf.Interface().(Elem), name)
+		}
+	}
+}
+
+// deepCopy copies elements of v recursively.  All elements of v that may
+// be modified by inheritance are explicitly copied.
+func deepCopy(v reflect.Value) reflect.Value {
+	switch v.Kind() {
+	case reflect.Ptr:
+		if v.IsNil() || v.Elem().Kind() != reflect.Struct {
+			return v
+		}
+		nv := reflect.New(v.Elem().Type())
+		nv.Elem().Set(v.Elem())
+		deepCopyRec(nv.Elem(), v.Elem())
+		return nv
+	case reflect.Slice:
+		nv := reflect.MakeSlice(v.Type(), v.Len(), v.Len())
+		for i := 0; i < v.Len(); i++ {
+			deepCopyRec(nv.Index(i), v.Index(i))
+		}
+		return nv
+	}
+	panic("deepCopy: must be called with pointer or slice")
+}
+
+// deepCopyRec is only called by deepCopy.
+func deepCopyRec(nv, v reflect.Value) {
+	if v.Kind() == reflect.Struct {
+		t := v.Type()
+		for i := 0; i < v.NumField(); i++ {
+			if name, attr := xmlName(t.Field(i)); name != "" && !attr {
+				deepCopyRec(nv.Field(i), v.Field(i))
+			}
+		}
+	} else {
+		nv.Set(deepCopy(v))
+	}
+}
+
+// newNode is used to insert a missing node during inheritance.
+func (cldr *CLDR) newNode(v, enc reflect.Value) reflect.Value {
+	n := reflect.New(v.Type())
+	for i := iter(v); !i.done(); i.next() {
+		if name, attr := xmlName(i.field()); name == "" || attr {
+			n.Elem().FieldByIndex(i.index).Set(i.value())
+		}
+	}
+	n.Interface().(Elem).GetCommon().setEnclosing(enc.Addr().Interface().(Elem))
+	return n
+}
+
+// v, parent must be pointers to struct
+func (cldr *CLDR) inheritFields(v, parent reflect.Value) (res reflect.Value, err error) {
+	t := v.Type()
+	nv := reflect.New(t)
+	nv.Elem().Set(v)
+	for i := iter(v); !i.done(); i.next() {
+		vf := i.value()
+		f := i.field()
+		name, attr := xmlName(f)
+		if name == "" || attr {
+			continue
+		}
+		pf := parent.FieldByIndex(i.index)
+		if blocking[name] {
+			if vf.IsNil() {
+				vf = pf
+			}
+			nv.Elem().FieldByIndex(i.index).Set(deepCopy(vf))
+			continue
+		}
+		switch f.Type.Kind() {
+		case reflect.Ptr:
+			if f.Type.Elem().Kind() == reflect.Struct {
+				if !vf.IsNil() {
+					if vf, err = cldr.inheritStructPtr(vf, pf); err != nil {
+						return reflect.Value{}, err
+					}
+					vf.Interface().(Elem).setEnclosing(nv.Interface().(Elem))
+					nv.Elem().FieldByIndex(i.index).Set(vf)
+				} else if !pf.IsNil() {
+					n := cldr.newNode(pf.Elem(), v)
+					if vf, err = cldr.inheritStructPtr(n, pf); err != nil {
+						return reflect.Value{}, err
+					}
+					vf.Interface().(Elem).setEnclosing(nv.Interface().(Elem))
+					nv.Elem().FieldByIndex(i.index).Set(vf)
+				}
+			}
+		case reflect.Slice:
+			vf, err := cldr.inheritSlice(nv.Elem(), vf, pf)
+			if err != nil {
+				return reflect.Zero(t), err
+			}
+			nv.Elem().FieldByIndex(i.index).Set(vf)
+		}
+	}
+	return nv, nil
+}
+
+func root(e Elem) *LDML {
+	for ; e.enclosing() != nil; e = e.enclosing() {
+	}
+	return e.(*LDML)
+}
+
+// inheritStructPtr first merges possible aliases in with v and then inherits
+// any underspecified elements from parent.
+func (cldr *CLDR) inheritStructPtr(v, parent reflect.Value) (r reflect.Value, err error) {
+	if !v.IsNil() {
+		e := v.Interface().(Elem).GetCommon()
+		alias := e.Alias
+		if alias == nil && !parent.IsNil() {
+			alias = parent.Interface().(Elem).GetCommon().Alias
+		}
+		if alias != nil {
+			a, err := cldr.resolveAlias(v.Interface().(Elem), alias.Source, alias.Path)
+			if a != nil {
+				if v, err = cldr.inheritFields(v.Elem(), reflect.ValueOf(a).Elem()); err != nil {
+					return reflect.Value{}, err
+				}
+			}
+		}
+		if !parent.IsNil() {
+			return cldr.inheritFields(v.Elem(), parent.Elem())
+		}
+	} else if parent.IsNil() {
+		panic("should not reach here")
+	}
+	return v, nil
+}
+
+// Must be slice of struct pointers.
+func (cldr *CLDR) inheritSlice(enc, v, parent reflect.Value) (res reflect.Value, err error) {
+	t := v.Type()
+	index := make(map[string]reflect.Value)
+	if !v.IsNil() {
+		for i := 0; i < v.Len(); i++ {
+			vi := v.Index(i)
+			key := attrKey(vi)
+			index[key] = vi
+		}
+	}
+	if !parent.IsNil() {
+		for i := 0; i < parent.Len(); i++ {
+			vi := parent.Index(i)
+			key := attrKey(vi)
+			if w, ok := index[key]; ok {
+				index[key], err = cldr.inheritStructPtr(w, vi)
+			} else {
+				n := cldr.newNode(vi.Elem(), enc)
+				index[key], err = cldr.inheritStructPtr(n, vi)
+			}
+			index[key].Interface().(Elem).setEnclosing(enc.Addr().Interface().(Elem))
+			if err != nil {
+				return v, err
+			}
+		}
+	}
+	keys := make([]string, 0, len(index))
+	for k, _ := range index {
+		keys = append(keys, k)
+	}
+	sort.Strings(keys)
+	sl := reflect.MakeSlice(t, len(index), len(index))
+	for i, k := range keys {
+		sl.Index(i).Set(index[k])
+	}
+	return sl, nil
+}
+
+func parentLocale(loc string) string {
+	parts := strings.Split(loc, "_")
+	if len(parts) == 1 {
+		return "root"
+	}
+	parts = parts[:len(parts)-1]
+	key := strings.Join(parts, "_")
+	return key
+}
+
+func (cldr *CLDR) resolve(loc string) (res *LDML, err error) {
+	if r := cldr.resolved[loc]; r != nil {
+		return r, nil
+	}
+	x := cldr.RawLDML(loc)
+	if x == nil {
+		return nil, fmt.Errorf("cldr: unknown locale %q", loc)
+	}
+	var v reflect.Value
+	if loc == "root" {
+		x = deepCopy(reflect.ValueOf(x)).Interface().(*LDML)
+		linkEnclosing(nil, x)
+		err = cldr.aliasResolver().visit(x)
+	} else {
+		key := parentLocale(loc)
+		var parent *LDML
+		for ; cldr.locale[key] == nil; key = parentLocale(key) {
+		}
+		if parent, err = cldr.resolve(key); err != nil {
+			return nil, err
+		}
+		v, err = cldr.inheritFields(reflect.ValueOf(x).Elem(), reflect.ValueOf(parent).Elem())
+		x = v.Interface().(*LDML)
+		linkEnclosing(nil, x)
+	}
+	if err != nil {
+		return nil, err
+	}
+	cldr.resolved[loc] = x
+	return x, err
+}
+
+// finalize finalizes the initialization of the raw LDML structs.  It also
+// removed unwanted fields, as specified by filter, so that they will not
+// be unnecessarily evaluated.
+func (cldr *CLDR) finalize(filter []string) {
+	for _, x := range cldr.locale {
+		if filter != nil {
+			v := reflect.ValueOf(x).Elem()
+			t := v.Type()
+			for i := 0; i < v.NumField(); i++ {
+				f := t.Field(i)
+				name, _ := xmlName(f)
+				if name != "" && name != "identity" && !in(filter, name) {
+					v.Field(i).Set(reflect.Zero(f.Type))
+				}
+			}
+		}
+		linkEnclosing(nil, x) // for resolving aliases and paths
+		setNames(x, "ldml")
+	}
+}

vendor/golang.org/x/text/unicode/cldr/slice.go

@@ -0,0 +1,144 @@
+// Copyright 2013 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package cldr
+
+import (
+	"fmt"
+	"reflect"
+	"sort"
+)
+
+// Slice provides utilities for modifying slices of elements.
+// It can be wrapped around any slice of which the element type implements
+// interface Elem.
+type Slice struct {
+	ptr reflect.Value
+	typ reflect.Type
+}
+
+// Value returns the reflect.Value of the underlying slice.
+func (s *Slice) Value() reflect.Value {
+	return s.ptr.Elem()
+}
+
+// MakeSlice wraps a pointer to a slice of Elems.
+// It replaces the array pointed to by the slice so that subsequent modifications
+// do not alter the data in a CLDR type.
+// It panics if an incorrect type is passed.
+func MakeSlice(slicePtr interface{}) Slice {
+	ptr := reflect.ValueOf(slicePtr)
+	if ptr.Kind() != reflect.Ptr {
+		panic(fmt.Sprintf("MakeSlice: argument must be pointer to slice, found %v", ptr.Type()))
+	}
+	sl := ptr.Elem()
+	if sl.Kind() != reflect.Slice {
+		panic(fmt.Sprintf("MakeSlice: argument must point to a slice, found %v", sl.Type()))
+	}
+	intf := reflect.TypeOf((*Elem)(nil)).Elem()
+	if !sl.Type().Elem().Implements(intf) {
+		panic(fmt.Sprintf("MakeSlice: element type of slice (%v) does not implement Elem", sl.Type().Elem()))
+	}
+	nsl := reflect.MakeSlice(sl.Type(), sl.Len(), sl.Len())
+	reflect.Copy(nsl, sl)
+	sl.Set(nsl)
+	return Slice{
+		ptr: ptr,
+		typ: sl.Type().Elem().Elem(),
+	}
+}
+
+func (s Slice) indexForAttr(a string) []int {
+	for i := iter(reflect.Zero(s.typ)); !i.done(); i.next() {
+		if n, _ := xmlName(i.field()); n == a {
+			return i.index
+		}
+	}
+	panic(fmt.Sprintf("MakeSlice: no attribute %q for type %v", a, s.typ))
+}
+
+// Filter filters s to only include elements for which fn returns true.
+func (s Slice) Filter(fn func(e Elem) bool) {
+	k := 0
+	sl := s.Value()
+	for i := 0; i < sl.Len(); i++ {
+		vi := sl.Index(i)
+		if fn(vi.Interface().(Elem)) {
+			sl.Index(k).Set(vi)
+			k++
+		}
+	}
+	sl.Set(sl.Slice(0, k))
+}
+
+// Group finds elements in s for which fn returns the same value and groups
+// them in a new Slice.
+func (s Slice) Group(fn func(e Elem) string) []Slice {
+	m := make(map[string][]reflect.Value)
+	sl := s.Value()
+	for i := 0; i < sl.Len(); i++ {
+		vi := sl.Index(i)
+		key := fn(vi.Interface().(Elem))
+		m[key] = append(m[key], vi)
+	}
+	keys := []string{}
+	for k, _ := range m {
+		keys = append(keys, k)
+	}
+	sort.Strings(keys)
+	res := []Slice{}
+	for _, k := range keys {
+		nsl := reflect.New(sl.Type())
+		nsl.Elem().Set(reflect.Append(nsl.Elem(), m[k]...))
+		res = append(res, MakeSlice(nsl.Interface()))
+	}
+	return res
+}
+
+// SelectAnyOf filters s to contain only elements for which attr matches
+// any of the values.
+func (s Slice) SelectAnyOf(attr string, values ...string) {
+	index := s.indexForAttr(attr)
+	s.Filter(func(e Elem) bool {
+		vf := reflect.ValueOf(e).Elem().FieldByIndex(index)
+		return in(values, vf.String())
+	})
+}
+
+// SelectOnePerGroup filters s to include at most one element e per group of
+// elements matching Key(attr), where e has an attribute a that matches any
+// the values in v.
+// If more than one element in a group matches a value in v preference
+// is given to the element that matches the first value in v.
+func (s Slice) SelectOnePerGroup(a string, v []string) {
+	index := s.indexForAttr(a)
+	grouped := s.Group(func(e Elem) string { return Key(e, a) })
+	sl := s.Value()
+	sl.Set(sl.Slice(0, 0))
+	for _, g := range grouped {
+		e := reflect.Value{}
+		found := len(v)
+		gsl := g.Value()
+		for i := 0; i < gsl.Len(); i++ {
+			vi := gsl.Index(i).Elem().FieldByIndex(index)
+			j := 0
+			for ; j < len(v) && v[j] != vi.String(); j++ {
+			}
+			if j < found {
+				found = j
+				e = gsl.Index(i)
+			}
+		}
+		if found < len(v) {
+			sl.Set(reflect.Append(sl, e))
+		}
+	}
+}
+
+// SelectDraft drops all elements from the list with a draft level smaller than d
+// and selects the highest draft level of the remaining.
+// This method assumes that the input CLDR is canonicalized.
+func (s Slice) SelectDraft(d Draft) {
+	s.SelectOnePerGroup("draft", drafts[len(drafts)-2-int(d):])
+}

vendor/golang.org/x/text/width/gen.go

@@ -0,0 +1,115 @@
+// Copyright 2015 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// +build ignore
+
+// This program generates the trie for width operations. The generated table
+// includes width category information as well as the normalization mappings.
+package main
+
+import (
+	"bytes"
+	"fmt"
+	"io"
+	"log"
+	"math"
+	"unicode/utf8"
+
+	"golang.org/x/text/internal/gen"
+	"golang.org/x/text/internal/triegen"
+)
+
+// See gen_common.go for flags.
+
+func main() {
+	gen.Init()
+	genTables()
+	genTests()
+	gen.Repackage("gen_trieval.go", "trieval.go", "width")
+	gen.Repackage("gen_common.go", "common_test.go", "width")
+}
+
+func genTables() {
+	t := triegen.NewTrie("width")
+	// fold and inverse mappings. See mapComment for a description of the format
+	// of each entry. Add dummy value to make an index of 0 mean no mapping.
+	inverse := [][4]byte{{}}
+	mapping := map[[4]byte]int{[4]byte{}: 0}
+
+	getWidthData(func(r rune, tag elem, alt rune) {
+		idx := 0
+		if alt != 0 {
+			var buf [4]byte
+			buf[0] = byte(utf8.EncodeRune(buf[1:], alt))
+			s := string(r)
+			buf[buf[0]] ^= s[len(s)-1]
+			var ok bool
+			if idx, ok = mapping[buf]; !ok {
+				idx = len(mapping)
+				if idx > math.MaxUint8 {
+					log.Fatalf("Index %d does not fit in a byte.", idx)
+				}
+				mapping[buf] = idx
+				inverse = append(inverse, buf)
+			}
+		}
+		t.Insert(r, uint64(tag|elem(idx)))
+	})
+
+	w := &bytes.Buffer{}
+	gen.WriteUnicodeVersion(w)
+
+	sz, err := t.Gen(w)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	sz += writeMappings(w, inverse)
+
+	fmt.Fprintf(w, "// Total table size %d bytes (%dKiB)\n", sz, sz/1024)
+
+	gen.WriteVersionedGoFile(*outputFile, "width", w.Bytes())
+}
+
+const inverseDataComment = `
+// inverseData contains 4-byte entries of the following format:
+//   <length> <modified UTF-8-encoded rune> <0 padding>
+// The last byte of the UTF-8-encoded rune is xor-ed with the last byte of the
+// UTF-8 encoding of the original rune. Mappings often have the following
+// pattern:
+//   Ａ -> A  (U+FF21 -> U+0041)
+//   Ｂ -> B  (U+FF22 -> U+0042)
+//   ...
+// By xor-ing the last byte the same entry can be shared by many mappings. This
+// reduces the total number of distinct entries by about two thirds.
+// The resulting entry for the aforementioned mappings is
+//   { 0x01, 0xE0, 0x00, 0x00 }
+// Using this entry to map U+FF21 (UTF-8 [EF BC A1]), we get
+//   E0 ^ A1 = 41.
+// Similarly, for U+FF22 (UTF-8 [EF BC A2]), we get
+//   E0 ^ A2 = 42.
+// Note that because of the xor-ing, the byte sequence stored in the entry is
+// not valid UTF-8.`
+
+func writeMappings(w io.Writer, data [][4]byte) int {
+	fmt.Fprintln(w, inverseDataComment)
+	fmt.Fprintf(w, "var inverseData = [%d][4]byte{\n", len(data))
+	for _, x := range data {
+		fmt.Fprintf(w, "{ 0x%02x, 0x%02x, 0x%02x, 0x%02x },\n", x[0], x[1], x[2], x[3])
+	}
+	fmt.Fprintln(w, "}")
+	return len(data) * 4
+}
+
+func genTests() {
+	w := &bytes.Buffer{}
+	fmt.Fprintf(w, "\nvar mapRunes = map[rune]struct{r rune; e elem}{\n")
+	getWidthData(func(r rune, tag elem, alt rune) {
+		if alt != 0 {
+			fmt.Fprintf(w, "\t0x%X: {0x%X, 0x%X},\n", r, alt, tag)
+		}
+	})
+	fmt.Fprintln(w, "}")
+	gen.WriteGoFile("runes_test.go", "width", w.Bytes())
+}

vendor/golang.org/x/text/width/gen_common.go

@@ -0,0 +1,96 @@
+// Copyright 2015 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// +build ignore
+
+package main
+
+// This code is shared between the main code generator and the test code.
+
+import (
+	"flag"
+	"log"
+	"strconv"
+	"strings"
+
+	"golang.org/x/text/internal/gen"
+	"golang.org/x/text/internal/ucd"
+)
+
+var (
+	outputFile = flag.String("out", "tables.go", "output file")
+)
+
+var typeMap = map[string]elem{
+	"A":  tagAmbiguous,
+	"N":  tagNeutral,
+	"Na": tagNarrow,
+	"W":  tagWide,
+	"F":  tagFullwidth,
+	"H":  tagHalfwidth,
+}
+
+// getWidthData calls f for every entry for which it is defined.
+//
+// f may be called multiple times for the same rune. The last call to f is the
+// correct value. f is not called for all runes. The default tag type is
+// Neutral.
+func getWidthData(f func(r rune, tag elem, alt rune)) {
+	// Set the default values for Unified Ideographs. In line with Annex 11,
+	// we encode full ranges instead of the defined runes in Unified_Ideograph.
+	for _, b := range []struct{ lo, hi rune }{
+		{0x4E00, 0x9FFF},   // the CJK Unified Ideographs block,
+		{0x3400, 0x4DBF},   // the CJK Unified Ideographs Externsion A block,
+		{0xF900, 0xFAFF},   // the CJK Compatibility Ideographs block,
+		{0x20000, 0x2FFFF}, // the Supplementary Ideographic Plane,
+		{0x30000, 0x3FFFF}, // the Tertiary Ideographic Plane,
+	} {
+		for r := b.lo; r <= b.hi; r++ {
+			f(r, tagWide, 0)
+		}
+	}
+
+	inverse := map[rune]rune{}
+	maps := map[string]bool{
+		"<wide>":   true,
+		"<narrow>": true,
+	}
+
+	// We cannot reuse package norm's decomposition, as we need an unexpanded
+	// decomposition. We make use of the opportunity to verify that the
+	// decomposition type is as expected.
+	ucd.Parse(gen.OpenUCDFile("UnicodeData.txt"), func(p *ucd.Parser) {
+		r := p.Rune(0)
+		s := strings.SplitN(p.String(ucd.DecompMapping), " ", 2)
+		if !maps[s[0]] {
+			return
+		}
+		x, err := strconv.ParseUint(s[1], 16, 32)
+		if err != nil {
+			log.Fatalf("Error parsing rune %q", s[1])
+		}
+		if inverse[r] != 0 || inverse[rune(x)] != 0 {
+			log.Fatalf("Circular dependency in mapping between %U and %U", r, x)
+		}
+		inverse[r] = rune(x)
+		inverse[rune(x)] = r
+	})
+
+	// <rune range>;<type>
+	ucd.Parse(gen.OpenUCDFile("EastAsianWidth.txt"), func(p *ucd.Parser) {
+		tag, ok := typeMap[p.String(1)]
+		if !ok {
+			log.Fatalf("Unknown width type %q", p.String(1))
+		}
+		r := p.Rune(0)
+		alt, ok := inverse[r]
+		if tag == tagFullwidth || tag == tagHalfwidth && r != wonSign {
+			tag |= tagNeedsFold
+			if !ok {
+				log.Fatalf("Narrow or wide rune %U has no decomposition", r)
+			}
+		}
+		f(r, tag, alt)
+	})
+}

vendor/golang.org/x/text/width/gen_trieval.go

@@ -0,0 +1,34 @@
+// Copyright 2015 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// +build ignore
+
+package main
+
+// elem is an entry of the width trie. The high byte is used to encode the type
+// of the rune. The low byte is used to store the index to a mapping entry in
+// the inverseData array.
+type elem uint16
+
+const (
+	tagNeutral elem = iota << typeShift
+	tagAmbiguous
+	tagWide
+	tagNarrow
+	tagFullwidth
+	tagHalfwidth
+)
+
+const (
+	numTypeBits = 3
+	typeShift   = 16 - numTypeBits
+
+	// tagNeedsFold is true for all fullwidth and halfwidth runes except for
+	// the Won sign U+20A9.
+	tagNeedsFold = 0x1000
+
+	// The Korean Won sign is halfwidth, but SHOULD NOT be mapped to a wide
+	// variant.
+	wonSign rune = 0x20A9
+)

vendor/golang.org/x/text/width/kind_string.go

@@ -0,0 +1,16 @@
+// Code generated by "stringer -type=Kind"; DO NOT EDIT.
+
+package width
+
+import "fmt"
+
+const _Kind_name = "NeutralEastAsianAmbiguousEastAsianWideEastAsianNarrowEastAsianFullwidthEastAsianHalfwidth"
+
+var _Kind_index = [...]uint8{0, 7, 25, 38, 53, 71, 89}
+
+func (i Kind) String() string {
+	if i < 0 || i >= Kind(len(_Kind_index)-1) {
+		return fmt.Sprintf("Kind(%d)", i)
+	}
+	return _Kind_name[_Kind_index[i]:_Kind_index[i+1]]
+}

vendor/golang.org/x/text/width/transform.go

@@ -0,0 +1,239 @@
+// Copyright 2015 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package width
+
+import (
+	"unicode/utf8"
+
+	"golang.org/x/text/transform"
+)
+
+type foldTransform struct {
+	transform.NopResetter
+}
+
+func (foldTransform) Span(src []byte, atEOF bool) (n int, err error) {
+	for n < len(src) {
+		if src[n] < utf8.RuneSelf {
+			// ASCII fast path.
+			for n++; n < len(src) && src[n] < utf8.RuneSelf; n++ {
+			}
+			continue
+		}
+		v, size := trie.lookup(src[n:])
+		if size == 0 { // incomplete UTF-8 encoding
+			if !atEOF {
+				err = transform.ErrShortSrc
+			} else {
+				n = len(src)
+			}
+			break
+		}
+		if elem(v)&tagNeedsFold != 0 {
+			err = transform.ErrEndOfSpan
+			break
+		}
+		n += size
+	}
+	return n, err
+}
+
+func (foldTransform) Transform(dst, src []byte, atEOF bool) (nDst, nSrc int, err error) {
+	for nSrc < len(src) {
+		if src[nSrc] < utf8.RuneSelf {
+			// ASCII fast path.
+			start, end := nSrc, len(src)
+			if d := len(dst) - nDst; d < end-start {
+				end = nSrc + d
+			}
+			for nSrc++; nSrc < end && src[nSrc] < utf8.RuneSelf; nSrc++ {
+			}
+			n := copy(dst[nDst:], src[start:nSrc])
+			if nDst += n; nDst == len(dst) {
+				nSrc = start + n
+				if nSrc == len(src) {
+					return nDst, nSrc, nil
+				}
+				if src[nSrc] < utf8.RuneSelf {
+					return nDst, nSrc, transform.ErrShortDst
+				}
+			}
+			continue
+		}
+		v, size := trie.lookup(src[nSrc:])
+		if size == 0 { // incomplete UTF-8 encoding
+			if !atEOF {
+				return nDst, nSrc, transform.ErrShortSrc
+			}
+			size = 1 // gobble 1 byte
+		}
+		if elem(v)&tagNeedsFold == 0 {
+			if size != copy(dst[nDst:], src[nSrc:nSrc+size]) {
+				return nDst, nSrc, transform.ErrShortDst
+			}
+			nDst += size
+		} else {
+			data := inverseData[byte(v)]
+			if len(dst)-nDst < int(data[0]) {
+				return nDst, nSrc, transform.ErrShortDst
+			}
+			i := 1
+			for end := int(data[0]); i < end; i++ {
+				dst[nDst] = data[i]
+				nDst++
+			}
+			dst[nDst] = data[i] ^ src[nSrc+size-1]
+			nDst++
+		}
+		nSrc += size
+	}
+	return nDst, nSrc, nil
+}
+
+type narrowTransform struct {
+	transform.NopResetter
+}
+
+func (narrowTransform) Span(src []byte, atEOF bool) (n int, err error) {
+	for n < len(src) {
+		if src[n] < utf8.RuneSelf {
+			// ASCII fast path.
+			for n++; n < len(src) && src[n] < utf8.RuneSelf; n++ {
+			}
+			continue
+		}
+		v, size := trie.lookup(src[n:])
+		if size == 0 { // incomplete UTF-8 encoding
+			if !atEOF {
+				err = transform.ErrShortSrc
+			} else {
+				n = len(src)
+			}
+			break
+		}
+		if k := elem(v).kind(); byte(v) == 0 || k != EastAsianFullwidth && k != EastAsianWide && k != EastAsianAmbiguous {
+		} else {
+			err = transform.ErrEndOfSpan
+			break
+		}
+		n += size
+	}
+	return n, err
+}
+
+func (narrowTransform) Transform(dst, src []byte, atEOF bool) (nDst, nSrc int, err error) {
+	for nSrc < len(src) {
+		if src[nSrc] < utf8.RuneSelf {
+			// ASCII fast path.
+			start, end := nSrc, len(src)
+			if d := len(dst) - nDst; d < end-start {
+				end = nSrc + d
+			}
+			for nSrc++; nSrc < end && src[nSrc] < utf8.RuneSelf; nSrc++ {
+			}
+			n := copy(dst[nDst:], src[start:nSrc])
+			if nDst += n; nDst == len(dst) {
+				nSrc = start + n
+				if nSrc == len(src) {
+					return nDst, nSrc, nil
+				}
+				if src[nSrc] < utf8.RuneSelf {
+					return nDst, nSrc, transform.ErrShortDst
+				}
+			}
+			continue
+		}
+		v, size := trie.lookup(src[nSrc:])
+		if size == 0 { // incomplete UTF-8 encoding
+			if !atEOF {
+				return nDst, nSrc, transform.ErrShortSrc
+			}
+			size = 1 // gobble 1 byte
+		}
+		if k := elem(v).kind(); byte(v) == 0 || k != EastAsianFullwidth && k != EastAsianWide && k != EastAsianAmbiguous {
+			if size != copy(dst[nDst:], src[nSrc:nSrc+size]) {
+				return nDst, nSrc, transform.ErrShortDst
+			}
+			nDst += size
+		} else {
+			data := inverseData[byte(v)]
+			if len(dst)-nDst < int(data[0]) {
+				return nDst, nSrc, transform.ErrShortDst
+			}
+			i := 1
+			for end := int(data[0]); i < end; i++ {
+				dst[nDst] = data[i]
+				nDst++
+			}
+			dst[nDst] = data[i] ^ src[nSrc+size-1]
+			nDst++
+		}
+		nSrc += size
+	}
+	return nDst, nSrc, nil
+}
+
+type wideTransform struct {
+	transform.NopResetter
+}
+
+func (wideTransform) Span(src []byte, atEOF bool) (n int, err error) {
+	for n < len(src) {
+		// TODO: Consider ASCII fast path. Special-casing ASCII handling can
+		// reduce the ns/op of BenchmarkWideASCII by about 30%. This is probably
+		// not enough to warrant the extra code and complexity.
+		v, size := trie.lookup(src[n:])
+		if size == 0 { // incomplete UTF-8 encoding
+			if !atEOF {
+				err = transform.ErrShortSrc
+			} else {
+				n = len(src)
+			}
+			break
+		}
+		if k := elem(v).kind(); byte(v) == 0 || k != EastAsianHalfwidth && k != EastAsianNarrow {
+		} else {
+			err = transform.ErrEndOfSpan
+			break
+		}
+		n += size
+	}
+	return n, err
+}
+
+func (wideTransform) Transform(dst, src []byte, atEOF bool) (nDst, nSrc int, err error) {
+	for nSrc < len(src) {
+		// TODO: Consider ASCII fast path. Special-casing ASCII handling can
+		// reduce the ns/op of BenchmarkWideASCII by about 30%. This is probably
+		// not enough to warrant the extra code and complexity.
+		v, size := trie.lookup(src[nSrc:])
+		if size == 0 { // incomplete UTF-8 encoding
+			if !atEOF {
+				return nDst, nSrc, transform.ErrShortSrc
+			}
+			size = 1 // gobble 1 byte
+		}
+		if k := elem(v).kind(); byte(v) == 0 || k != EastAsianHalfwidth && k != EastAsianNarrow {
+			if size != copy(dst[nDst:], src[nSrc:nSrc+size]) {
+				return nDst, nSrc, transform.ErrShortDst
+			}
+			nDst += size
+		} else {
+			data := inverseData[byte(v)]
+			if len(dst)-nDst < int(data[0]) {
+				return nDst, nSrc, transform.ErrShortDst
+			}
+			i := 1
+			for end := int(data[0]); i < end; i++ {
+				dst[nDst] = data[i]
+				nDst++
+			}
+			dst[nDst] = data[i] ^ src[nSrc+size-1]
+			nDst++
+		}
+		nSrc += size
+	}
+	return nDst, nSrc, nil
+}

vendor/golang.org/x/text/width/trieval.go

@@ -0,0 +1,30 @@
+// Code generated by running "go generate" in golang.org/x/text. DO NOT EDIT.
+
+package width
+
+// elem is an entry of the width trie. The high byte is used to encode the type
+// of the rune. The low byte is used to store the index to a mapping entry in
+// the inverseData array.
+type elem uint16
+
+const (
+	tagNeutral elem = iota << typeShift
+	tagAmbiguous
+	tagWide
+	tagNarrow
+	tagFullwidth
+	tagHalfwidth
+)
+
+const (
+	numTypeBits = 3
+	typeShift   = 16 - numTypeBits
+
+	// tagNeedsFold is true for all fullwidth and halfwidth runes except for
+	// the Won sign U+20A9.
+	tagNeedsFold = 0x1000
+
+	// The Korean Won sign is halfwidth, but SHOULD NOT be mapped to a wide
+	// variant.
+	wonSign rune = 0x20A9
+)

vendor/golang.org/x/text/width/width.go

@@ -0,0 +1,206 @@
+// Copyright 2015 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:generate stringer -type=Kind
+//go:generate go run gen.go gen_common.go gen_trieval.go
+
+// Package width provides functionality for handling different widths in text.
+//
+// Wide characters behave like ideographs; they tend to allow line breaks after
+// each character and remain upright in vertical text layout. Narrow characters
+// are kept together in words or runs that are rotated sideways in vertical text
+// layout.
+//
+// For more information, see http://unicode.org/reports/tr11/.
+package width // import "golang.org/x/text/width"
+
+import (
+	"unicode/utf8"
+
+	"golang.org/x/text/transform"
+)
+
+// TODO
+// 1) Reduce table size by compressing blocks.
+// 2) API proposition for computing display length
+//    (approximation, fixed pitch only).
+// 3) Implement display length.
+
+// Kind indicates the type of width property as defined in http://unicode.org/reports/tr11/.
+type Kind int
+
+const (
+	// Neutral characters do not occur in legacy East Asian character sets.
+	Neutral Kind = iota
+
+	// EastAsianAmbiguous characters that can be sometimes wide and sometimes
+	// narrow and require additional information not contained in the character
+	// code to further resolve their width.
+	EastAsianAmbiguous
+
+	// EastAsianWide characters are wide in its usual form. They occur only in
+	// the context of East Asian typography. These runes may have explicit
+	// halfwidth counterparts.
+	EastAsianWide
+
+	// EastAsianNarrow characters are narrow in its usual form. They often have
+	// fullwidth counterparts.
+	EastAsianNarrow
+
+	// Note: there exist Narrow runes that do not have fullwidth or wide
+	// counterparts, despite what the definition says (e.g. U+27E6).
+
+	// EastAsianFullwidth characters have a compatibility decompositions of type
+	// wide that map to a narrow counterpart.
+	EastAsianFullwidth
+
+	// EastAsianHalfwidth characters have a compatibility decomposition of type
+	// narrow that map to a wide or ambiguous counterpart, plus U+20A9 ₩ WON
+	// SIGN.
+	EastAsianHalfwidth
+
+	// Note: there exist runes that have a halfwidth counterparts but that are
+	// classified as Ambiguous, rather than wide (e.g. U+2190).
+)
+
+// TODO: the generated tries need to return size 1 for invalid runes for the
+// width to be computed correctly (each byte should render width 1)
+
+var trie = newWidthTrie(0)
+
+// Lookup reports the Properties of the first rune in b and the number of bytes
+// of its UTF-8 encoding.
+func Lookup(b []byte) (p Properties, size int) {
+	v, sz := trie.lookup(b)
+	return Properties{elem(v), b[sz-1]}, sz
+}
+
+// LookupString reports the Properties of the first rune in s and the number of
+// bytes of its UTF-8 encoding.
+func LookupString(s string) (p Properties, size int) {
+	v, sz := trie.lookupString(s)
+	return Properties{elem(v), s[sz-1]}, sz
+}
+
+// LookupRune reports the Properties of rune r.
+func LookupRune(r rune) Properties {
+	var buf [4]byte
+	n := utf8.EncodeRune(buf[:], r)
+	v, _ := trie.lookup(buf[:n])
+	last := byte(r)
+	if r >= utf8.RuneSelf {
+		last = 0x80 + byte(r&0x3f)
+	}
+	return Properties{elem(v), last}
+}
+
+// Properties provides access to width properties of a rune.
+type Properties struct {
+	elem elem
+	last byte
+}
+
+func (e elem) kind() Kind {
+	return Kind(e >> typeShift)
+}
+
+// Kind returns the Kind of a rune as defined in Unicode TR #11.
+// See http://unicode.org/reports/tr11/ for more details.
+func (p Properties) Kind() Kind {
+	return p.elem.kind()
+}
+
+// Folded returns the folded variant of a rune or 0 if the rune is canonical.
+func (p Properties) Folded() rune {
+	if p.elem&tagNeedsFold != 0 {
+		buf := inverseData[byte(p.elem)]
+		buf[buf[0]] ^= p.last
+		r, _ := utf8.DecodeRune(buf[1 : 1+buf[0]])
+		return r
+	}
+	return 0
+}
+
+// Narrow returns the narrow variant of a rune or 0 if the rune is already
+// narrow or doesn't have a narrow variant.
+func (p Properties) Narrow() rune {
+	if k := p.elem.kind(); byte(p.elem) != 0 && (k == EastAsianFullwidth || k == EastAsianWide || k == EastAsianAmbiguous) {
+		buf := inverseData[byte(p.elem)]
+		buf[buf[0]] ^= p.last
+		r, _ := utf8.DecodeRune(buf[1 : 1+buf[0]])
+		return r
+	}
+	return 0
+}
+
+// Wide returns the wide variant of a rune or 0 if the rune is already
+// wide or doesn't have a wide variant.
+func (p Properties) Wide() rune {
+	if k := p.elem.kind(); byte(p.elem) != 0 && (k == EastAsianHalfwidth || k == EastAsianNarrow) {
+		buf := inverseData[byte(p.elem)]
+		buf[buf[0]] ^= p.last
+		r, _ := utf8.DecodeRune(buf[1 : 1+buf[0]])
+		return r
+	}
+	return 0
+}
+
+// TODO for Properties:
+// - Add Fullwidth/Halfwidth or Inverted methods for computing variants
+// mapping.
+// - Add width information (including information on non-spacing runes).
+
+// Transformer implements the transform.Transformer interface.
+type Transformer struct {
+	t transform.SpanningTransformer
+}
+
+// Reset implements the transform.Transformer interface.
+func (t Transformer) Reset() { t.t.Reset() }
+
+// Transform implements the transform.Transformer interface.
+func (t Transformer) Transform(dst, src []byte, atEOF bool) (nDst, nSrc int, err error) {
+	return t.t.Transform(dst, src, atEOF)
+}
+
+// Span implements the transform.SpanningTransformer interface.
+func (t Transformer) Span(src []byte, atEOF bool) (n int, err error) {
+	return t.t.Span(src, atEOF)
+}
+
+// Bytes returns a new byte slice with the result of applying t to b.
+func (t Transformer) Bytes(b []byte) []byte {
+	b, _, _ = transform.Bytes(t, b)
+	return b
+}
+
+// String returns a string with the result of applying t to s.
+func (t Transformer) String(s string) string {
+	s, _, _ = transform.String(t, s)
+	return s
+}
+
+var (
+	// Fold is a transform that maps all runes to their canonical width.
+	//
+	// Note that the NFKC and NFKD transforms in golang.org/x/text/unicode/norm
+	// provide a more generic folding mechanism.
+	Fold Transformer = Transformer{foldTransform{}}
+
+	// Widen is a transform that maps runes to their wide variant, if
+	// available.
+	Widen Transformer = Transformer{wideTransform{}}
+
+	// Narrow is a transform that maps runes to their narrow variant, if
+	// available.
+	Narrow Transformer = Transformer{narrowTransform{}}
+)
+
+// TODO: Consider the following options:
+// - Treat Ambiguous runes that have a halfwidth counterpart as wide, or some
+//   generalized variant of this.
+// - Consider a wide Won character to be the default width (or some generalized
+//   variant of this).
+// - Filter the set of characters that gets converted (the preferred approach is
+//   to allow applying filters to transforms).