--- /dev/null
+// 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"
+ "bytes"
+ "errors"
+ "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 []byte
+ field [][]byte
+ // parsedRange is needed in case Range(0) is called more than once for one
+ // field. In some cases this requires scanning ahead.
+ parsedRange bool
+ rangeStart, rangeEnd rune
+
+ partHandler func(p *Parser)
+ commentHandler func(s string)
+}
+
+func (p *Parser) setError(err error) {
+ if p.err == nil {
+ p.err = err
+ }
+}
+
+func (p *Parser) getField(i int) []byte {
+ if i >= len(p.field) {
+ return nil
+ }
+ 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 = nil
+ p.field = p.field[:0]
+ p.parsedRange = false
+
+ for p.scanner.Scan() {
+ b := p.scanner.Bytes()
+ if len(b) == 0 {
+ continue
+ }
+ if b[0] == '#' {
+ if p.commentHandler != nil {
+ p.commentHandler(strings.TrimSpace(string(b[1:])))
+ }
+ continue
+ }
+
+ // Parse line
+ if i := bytes.IndexByte(b, '#'); i != -1 {
+ p.comment = bytes.TrimSpace(b[i+1:])
+ b = b[:i]
+ }
+ if b[0] == '@' {
+ if p.partHandler != nil {
+ p.field = append(p.field, bytes.TrimSpace(b[1:]))
+ p.partHandler(p)
+ p.field = p.field[:0]
+ }
+ p.comment = nil
+ continue
+ }
+ for {
+ i := bytes.IndexByte(b, ';')
+ if i == -1 {
+ p.field = append(p.field, bytes.TrimSpace(b))
+ break
+ }
+ p.field = append(p.field, bytes.TrimSpace(b[:i]))
+ b = b[i+1:]
+ }
+ if !p.keepRanges {
+ p.rangeStart, p.rangeEnd = p.getRange(0)
+ }
+ return true
+ }
+ p.setError(p.scanner.Err())
+ return false
+}
+
+func parseRune(b []byte) (rune, error) {
+ if len(b) > 2 && b[0] == 'U' && b[1] == '+' {
+ b = b[2:]
+ }
+ x, err := strconv.ParseUint(string(b), 16, 32)
+ return rune(x), err
+}
+
+func (p *Parser) parseRune(b []byte) rune {
+ x, err := parseRune(b)
+ p.setError(err)
+ 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(b []byte) {
+ if b = bytes.TrimSpace(b); len(b) > 0 {
+ runes = append(runes, p.parseRune(b))
+ }
+ }
+ for b := p.getField(i); ; {
+ i := bytes.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 := bytes.Index(b, []byte("..")); 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 && bytes.HasSuffix(p.field[1], []byte("First>")) {
+ if p.parsedRange {
+ return p.rangeStart, p.rangeEnd
+ }
+ mf := reRange.FindStringSubmatch(p.scanner.Text())
+ 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.Bytes()[: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 {
+ b := p.getField(i)
+ for s, v := range bools {
+ if bstrEq(b, s) {
+ return v
+ }
+ }
+ p.setError(strconv.ErrSyntax)
+ 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)
+ 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)
+ 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)
+ 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 {
+ b := p.getField(i)
+ for _, s := range enum {
+ if bstrEq(b, s) {
+ return s
+ }
+ }
+ p.setError(errUndefinedEnum)
+ return ""
+}
+
+func bstrEq(b []byte, s string) bool {
+ if len(b) != len(s) {
+ return false
+ }
+ for i, c := range b {
+ if c != s[i] {
+ return false
+ }
+ }
+ return true
+}
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