| // 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:build ignore |
| // +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] } |