1// Copyright 2015 The Go Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style
3// license that can be found in the LICENSE file.
4
5// +build ignore
6
7package main
8
9// This code is shared between the main code generator and the test code.
10
11import (
12	"flag"
13	"log"
14	"strconv"
15	"strings"
16
17	"golang.org/x/text/internal/gen"
18	"golang.org/x/text/internal/ucd"
19)
20
21var (
22	outputFile = flag.String("out", "tables.go", "output file")
23)
24
25var typeMap = map[string]elem{
26	"A":  tagAmbiguous,
27	"N":  tagNeutral,
28	"Na": tagNarrow,
29	"W":  tagWide,
30	"F":  tagFullwidth,
31	"H":  tagHalfwidth,
32}
33
34// getWidthData calls f for every entry for which it is defined.
35//
36// f may be called multiple times for the same rune. The last call to f is the
37// correct value. f is not called for all runes. The default tag type is
38// Neutral.
39func getWidthData(f func(r rune, tag elem, alt rune)) {
40	// Set the default values for Unified Ideographs. In line with Annex 11,
41	// we encode full ranges instead of the defined runes in Unified_Ideograph.
42	for _, b := range []struct{ lo, hi rune }{
43		{0x4E00, 0x9FFF},   // the CJK Unified Ideographs block,
44		{0x3400, 0x4DBF},   // the CJK Unified Ideographs Externsion A block,
45		{0xF900, 0xFAFF},   // the CJK Compatibility Ideographs block,
46		{0x20000, 0x2FFFF}, // the Supplementary Ideographic Plane,
47		{0x30000, 0x3FFFF}, // the Tertiary Ideographic Plane,
48	} {
49		for r := b.lo; r <= b.hi; r++ {
50			f(r, tagWide, 0)
51		}
52	}
53
54	inverse := map[rune]rune{}
55	maps := map[string]bool{
56		"<wide>":   true,
57		"<narrow>": true,
58	}
59
60	// We cannot reuse package norm's decomposition, as we need an unexpanded
61	// decomposition. We make use of the opportunity to verify that the
62	// decomposition type is as expected.
63	ucd.Parse(gen.OpenUCDFile("UnicodeData.txt"), func(p *ucd.Parser) {
64		r := p.Rune(0)
65		s := strings.SplitN(p.String(ucd.DecompMapping), " ", 2)
66		if !maps[s[0]] {
67			return
68		}
69		x, err := strconv.ParseUint(s[1], 16, 32)
70		if err != nil {
71			log.Fatalf("Error parsing rune %q", s[1])
72		}
73		if inverse[r] != 0 || inverse[rune(x)] != 0 {
74			log.Fatalf("Circular dependency in mapping between %U and %U", r, x)
75		}
76		inverse[r] = rune(x)
77		inverse[rune(x)] = r
78	})
79
80	// <rune range>;<type>
81	ucd.Parse(gen.OpenUCDFile("EastAsianWidth.txt"), func(p *ucd.Parser) {
82		tag, ok := typeMap[p.String(1)]
83		if !ok {
84			log.Fatalf("Unknown width type %q", p.String(1))
85		}
86		r := p.Rune(0)
87		alt, ok := inverse[r]
88		if tag == tagFullwidth || tag == tagHalfwidth && r != wonSign {
89			tag |= tagNeedsFold
90			if !ok {
91				log.Fatalf("Narrow or wide rune %U has no decomposition", r)
92			}
93		}
94		f(r, tag, alt)
95	})
96}
97