diff options
Diffstat (limited to 'vendor/golang.org/x/text/encoding/traditionalchinese/maketables.go')
-rw-r--r-- | vendor/golang.org/x/text/encoding/traditionalchinese/maketables.go | 140 |
1 files changed, 140 insertions, 0 deletions
diff --git a/vendor/golang.org/x/text/encoding/traditionalchinese/maketables.go b/vendor/golang.org/x/text/encoding/traditionalchinese/maketables.go new file mode 100644 index 000000000..cf7fdb31a --- /dev/null +++ b/vendor/golang.org/x/text/encoding/traditionalchinese/maketables.go @@ -0,0 +1,140 @@ +// 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 + +package main + +// This program generates tables.go: +// go run maketables.go | gofmt > tables.go + +import ( + "bufio" + "fmt" + "log" + "net/http" + "sort" + "strings" +) + +func main() { + fmt.Printf("// generated by go run maketables.go; DO NOT EDIT\n\n") + fmt.Printf("// Package traditionalchinese provides Traditional Chinese encodings such as Big5.\n") + fmt.Printf(`package traditionalchinese // import "golang.org/x/text/encoding/traditionalchinese"` + "\n\n") + + res, err := http.Get("http://encoding.spec.whatwg.org/index-big5.txt") + if err != nil { + log.Fatalf("Get: %v", err) + } + defer res.Body.Close() + + mapping := [65536]uint32{} + reverse := [65536 * 4]uint16{} + + scanner := bufio.NewScanner(res.Body) + for scanner.Scan() { + s := strings.TrimSpace(scanner.Text()) + if s == "" || s[0] == '#' { + continue + } + x, y := uint16(0), uint32(0) + if _, err := fmt.Sscanf(s, "%d 0x%x", &x, &y); err != nil { + log.Fatalf("could not parse %q", s) + } + if x < 0 || 126*157 <= x { + log.Fatalf("Big5 code %d is out of range", x) + } + mapping[x] = y + + // The WHATWG spec http://encoding.spec.whatwg.org/#indexes says that + // "The index pointer for code point in index is the first pointer + // corresponding to code point in index", which would normally mean + // that the code below should be guarded by "if reverse[y] == 0", but + // last instead of first seems to match the behavior of + // "iconv -f UTF-8 -t BIG5". For example, U+8005 者 occurs twice in + // http://encoding.spec.whatwg.org/index-big5.txt, as index 2148 + // (encoded as "\x8e\xcd") and index 6543 (encoded as "\xaa\xcc") + // and "echo 者 | iconv -f UTF-8 -t BIG5 | xxd" gives "\xaa\xcc". + c0, c1 := x/157, x%157 + if c1 < 0x3f { + c1 += 0x40 + } else { + c1 += 0x62 + } + reverse[y] = (0x81+c0)<<8 | c1 + } + if err := scanner.Err(); err != nil { + log.Fatalf("scanner error: %v", err) + } + + fmt.Printf("// decode is the decoding table from Big5 code to Unicode.\n") + fmt.Printf("// It is defined at http://encoding.spec.whatwg.org/index-big5.txt\n") + fmt.Printf("var decode = [...]uint32{\n") + for i, v := range mapping { + if v != 0 { + fmt.Printf("\t%d: 0x%08X,\n", i, v) + } + } + fmt.Printf("}\n\n") + + // Any run of at least separation continuous zero entries in the reverse map will + // be a separate encode table. + const separation = 1024 + + intervals := []interval(nil) + low, high := -1, -1 + for i, v := range reverse { + if v == 0 { + continue + } + if low < 0 { + low = i + } else if i-high >= separation { + if high >= 0 { + intervals = append(intervals, interval{low, high}) + } + low = i + } + high = i + 1 + } + if high >= 0 { + intervals = append(intervals, interval{low, high}) + } + sort.Sort(byDecreasingLength(intervals)) + + fmt.Printf("const numEncodeTables = %d\n\n", len(intervals)) + fmt.Printf("// encodeX are the encoding tables from Unicode to Big5 code,\n") + fmt.Printf("// sorted by decreasing length.\n") + for i, v := range intervals { + fmt.Printf("// encode%d: %5d entries for runes in [%6d, %6d).\n", i, v.len(), v.low, v.high) + } + fmt.Printf("\n") + + for i, v := range intervals { + fmt.Printf("const encode%dLow, encode%dHigh = %d, %d\n\n", i, i, v.low, v.high) + fmt.Printf("var encode%d = [...]uint16{\n", i) + for j := v.low; j < v.high; j++ { + x := reverse[j] + if x == 0 { + continue + } + fmt.Printf("\t%d-%d: 0x%04X,\n", j, v.low, x) + } + fmt.Printf("}\n\n") + } +} + +// interval is a half-open interval [low, high). +type interval struct { + low, high int +} + +func (i interval) len() int { return i.high - i.low } + +// byDecreasingLength sorts intervals by decreasing length. +type byDecreasingLength []interval + +func (b byDecreasingLength) Len() int { return len(b) } +func (b byDecreasingLength) Less(i, j int) bool { return b[i].len() > b[j].len() } +func (b byDecreasingLength) Swap(i, j int) { b[i], b[j] = b[j], b[i] } |