github.com/yanyiwu/go@v0.0.0-20150106053140-03d6637dbb7f/test/stringrange.go (about)

     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 range over strings.
     8  
     9  package main
    10  
    11  import (
    12  	"fmt"
    13  	"os"
    14  	"unicode/utf8"
    15  )
    16  
    17  func main() {
    18  	s := "\000\123\x00\xca\xFE\u0123\ubabe\U0000babe\U0010FFFFx"
    19  	expect := []rune{0, 0123, 0, 0xFFFD, 0xFFFD, 0x123, 0xbabe, 0xbabe, 0x10FFFF, 'x'}
    20  	offset := 0
    21  	var i int
    22  	var c rune
    23  	ok := true
    24  	cnum := 0
    25  	for i, c = range s {
    26  		r, size := utf8.DecodeRuneInString(s[i:len(s)]) // check it another way
    27  		if i != offset {
    28  			fmt.Printf("unexpected offset %d not %d\n", i, offset)
    29  			ok = false
    30  		}
    31  		if r != expect[cnum] {
    32  			fmt.Printf("unexpected rune %d from DecodeRuneInString: %x not %x\n", i, r, expect[cnum])
    33  			ok = false
    34  		}
    35  		if c != expect[cnum] {
    36  			fmt.Printf("unexpected rune %d from range: %x not %x\n", i, r, expect[cnum])
    37  			ok = false
    38  		}
    39  		offset += size
    40  		cnum++
    41  	}
    42  	if i != len(s)-1 {
    43  		fmt.Println("after loop i is", i, "not", len(s)-1)
    44  		ok = false
    45  	}
    46  
    47  	i = 12345
    48  	c = 23456
    49  	for i, c = range "" {
    50  	}
    51  	if i != 12345 {
    52  		fmt.Println("range empty string assigned to index:", i)
    53  		ok = false
    54  	}
    55  	if c != 23456 {
    56  		fmt.Println("range empty string assigned to value:", c)
    57  		ok = false
    58  	}
    59  
    60  	for _, c := range "a\xed\xa0\x80a" {
    61  		if c != 'a' && c != utf8.RuneError {
    62  			fmt.Printf("surrogate UTF-8 does not error: %U\n", c)
    63  			ok = false
    64  		}
    65  	}
    66  
    67  	if !ok {
    68  		fmt.Println("BUG: stringrange")
    69  		os.Exit(1)
    70  	}
    71  }