libgo/runtime/string.goc

   1 // Copyright 2009, 2010 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 package runtime
   6 #include "runtime.h"
   7 #include "arch.h"
   8 #include "malloc.h"
   9
  10 #define charntorune(pv, str, len) __go_get_rune(str, len, pv)
  11
  12 int32
  13 runtime_findnull(const byte *s)
  14 {
  15         if(s == nil)
  16                 return 0;
  17         return __builtin_strlen((const char*) s);
  18 }
  19
  20 String
  21 runtime_gostringnocopy(const byte *str)
  22 {
  23         String s;
  24
  25         s.__data = (const unsigned char *) str;
  26         s.__length = runtime_findnull(str);
  27         return s;
  28 }
  29
  30 enum
  31 {
  32         Runeself        = 0x80,
  33 };
  34
  35 func stringiter(s String, k int) (retk int) {
  36         int32 l;
  37
  38         if(k >= s.__length) {
  39                 // retk=0 is end of iteration
  40                 retk = 0;
  41                 goto out;
  42         }
  43
  44         l = s.__data[k];
  45         if(l < Runeself) {
  46                 retk = k+1;
  47                 goto out;
  48         }
  49
  50         // multi-char rune
  51         retk = k + charntorune(&l, s.__data+k, s.__length-k);
  52
  53 out:
  54 }
  55
  56 func stringiter2(s String, k int) (retk int, retv int) {
  57         if(k >= s.__length) {
  58                 // retk=0 is end of iteration
  59                 retk = 0;
  60                 retv = 0;
  61                 goto out;
  62         }
  63
  64         retv = s.__data[k];
  65         if(retv < Runeself) {
  66                 retk = k+1;
  67                 goto out;
  68         }
  69
  70         // multi-char rune
  71         retk = k + charntorune(&retv, s.__data+k, s.__length-k);
  72
  73 out:
  74 }