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// Copyright 2009 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.
#include "runtime.h"
static int32 empty = 0;
string emptystring = (string)∅
int32
findnull(int8 *s)
{
int32 l;
for(l=0; s[l]!=0; l++)
;
return l;
}
void
sys·catstring(string s1, string s2, string s3)
{
uint32 l;
if(s1 == nil || s1->len == 0) {
s3 = s2;
goto out;
}
if(s2 == nil || s2->len == 0) {
s3 = s1;
goto out;
}
l = s1->len + s2->len;
s3 = mal(sizeof(s3->len)+l);
s3->len = l;
mcpy(s3->str, s1->str, s1->len);
mcpy(s3->str+s1->len, s2->str, s2->len);
out:
FLUSH(&s3);
}
static void
prbounds(int8* s, int32 a, int32 b, int32 c)
{
int32 i;
prints(s);
prints(" ");
sys·printint(a);
prints("<");
sys·printint(b);
prints(">");
sys·printint(c);
prints("\n");
throw("bounds");
}
uint32
cmpstring(string s1, string s2)
{
uint32 i, l;
byte c1, c2;
if(s1 == nil)
s1 = emptystring;
if(s2 == nil)
s2 = emptystring;
l = s1->len;
if(s2->len < l)
l = s2->len;
for(i=0; i<l; i++) {
c1 = s1->str[i];
c2 = s2->str[i];
if(c1 < c2)
return -1;
if(c1 > c2)
return +1;
}
if(s1->len < s2->len)
return -1;
if(s1->len > s2->len)
return +1;
return 0;
}
void
sys·cmpstring(string s1, string s2, int32 v)
{
v = cmpstring(s1, s2);
FLUSH(&v);
}
int32
strcmp(byte *s1, byte *s2)
{
uint32 i;
byte c1, c2;
for(i=0;; i++) {
c1 = s1[i];
c2 = s2[i];
if(c1 < c2)
return -1;
if(c1 > c2)
return +1;
if(c1 == 0)
return 0;
}
}
void
sys·slicestring(string si, int32 lindex, int32 hindex, string so)
{
string s, str;
int32 l;
if(si == nil)
si = emptystring;
if(lindex < 0 || lindex > si->len ||
hindex < lindex || hindex > si->len) {
sys·printpc(&si);
prints(" ");
prbounds("slice", lindex, si->len, hindex);
}
l = hindex-lindex;
so = mal(sizeof(so->len)+l);
so->len = l;
mcpy(so->str, si->str+lindex, l);
FLUSH(&so);
}
void
sys·indexstring(string s, int32 i, byte b)
{
if(s == nil)
s = emptystring;
if(i < 0 || i >= s->len) {
sys·printpc(&s);
prints(" ");
prbounds("index", 0, i, s->len);
}
b = s->str[i];
FLUSH(&b);
}
/*
* this is the plan9 runetochar
* extended for 36 bits in 7 bytes
* note that it truncates to 32 bits
* through the argument passing.
*/
static int32
runetochar(byte *str, uint32 c)
{
int32 i, n;
uint32 mask, mark;
/*
* one character in 7 bits
*/
if(c <= 0x07FUL) {
str[0] = c;
return 1;
}
/*
* every new character picks up 5 bits
* one less in the first byte and
* six more in an extension byte
*/
mask = 0x7ffUL;
mark = 0xC0UL;
for(n=1;; n++) {
if(c <= mask)
break;
mask = (mask<<5) | 0x1fUL;
mark = (mark>>1) | 0x80UL;
}
/*
* lay down the bytes backwards
* n is the number of extension bytes
* mask is the max codepoint
* mark is the zeroth byte indicator
*/
for(i=n; i>0; i--) {
str[i] = 0x80UL | (c&0x3fUL);
c >>= 6;
}
str[0] = mark|c;
return n+1;
}
void
sys·intstring(int64 v, string s)
{
int32 l;
s = mal(sizeof(s->len)+8);
s->len = runetochar(s->str, v);
FLUSH(&s);
}
void
sys·byteastring(byte *a, int32 l, string s)
{
s = mal(sizeof(s->len)+l);
s->len = l;
mcpy(s->str, a, l);
FLUSH(&s);
}
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