1// run
2
3// Copyright 2009 The Go Authors. All rights reserved.
4// Use of this source code is governed by a BSD-style
5// license that can be found in the LICENSE file.
6
7// Test UTF-8 in strings and character constants.
8
9package main
10
11import "unicode/utf8"
12
13func main() {
14	var chars [6]rune
15	chars[0] = 'a'
16	chars[1] = 'b'
17	chars[2] = 'c'
18	chars[3] = '\u65e5'
19	chars[4] = '\u672c'
20	chars[5] = '\u8a9e'
21	s := ""
22	for i := 0; i < 6; i++ {
23		s += string(chars[i])
24	}
25	var l = len(s)
26	for w, i, j := 0, 0, 0; i < l; i += w {
27		var r rune
28		r, w = utf8.DecodeRuneInString(s[i:len(s)])
29		if w == 0 {
30			panic("zero width in string")
31		}
32		if r != chars[j] {
33			panic("wrong value from string")
34		}
35		j++
36	}
37	// encoded as bytes:  'a' 'b' 'c' e6 97 a5 e6 9c ac e8 aa 9e
38	const L = 12
39	if L != l {
40		panic("wrong length constructing array")
41	}
42	a := make([]byte, L)
43	a[0] = 'a'
44	a[1] = 'b'
45	a[2] = 'c'
46	a[3] = 0xe6
47	a[4] = 0x97
48	a[5] = 0xa5
49	a[6] = 0xe6
50	a[7] = 0x9c
51	a[8] = 0xac
52	a[9] = 0xe8
53	a[10] = 0xaa
54	a[11] = 0x9e
55	for w, i, j := 0, 0, 0; i < L; i += w {
56		var r rune
57		r, w = utf8.DecodeRune(a[i:L])
58		if w == 0 {
59			panic("zero width in bytes")
60		}
61		if r != chars[j] {
62			panic("wrong value from bytes")
63		}
64		j++
65	}
66}
67