traverseda
/
cpython
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

Optimized single-character strings gotten from s[i].

This commit is contained in:
Guido van Rossum 1991-04-04 10:48:33 +00:00
parent e6c67a7263
commit daa8bb334d
1 changed files with 23 additions and 13 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

36
Objects/stringobject.c
View File

@ -241,28 +241,38 @@ stringslice(a, i, j)
return newsizedstringobject(a->ob_sval + i, (int) (j-i));
}
#ifdef __STDC__
#include <limits.h>
#else
#ifndef UCHAR_MAX
#define UCHAR_MAX 255
#endif
#endif
static object *characters[UCHAR_MAX + 1];
static object *
stringitem(a, i)
stringobject *a;
register int i;
{
/* This is optimized since this is a common operation! */
register stringobject *op;
int c;
object *v;
if (i < 0 || i >= a->ob_size) {
err_setstr(IndexError, "string index out of range");
return NULL;
}
op = (stringobject *)
malloc(sizeof(stringobject) + sizeof(char));
if (op == NULL)
return err_nomem();
NEWREF(op);
op->ob_type = &Stringtype;
op->ob_size = 1;
op->ob_sval[0] = a->ob_sval[i];
op->ob_sval[1] = '\0';
return (object *) op;
c = a->ob_sval[i] & UCHAR_MAX;
v = characters[c];
if (v == NULL) {
v = newsizedstringobject((char *)NULL, 1);
if (v == NULL)
return NULL;
characters[c] = v;
((stringobject *)v)->ob_sval[0] = c;
}
INCREF(v);
return v;
}
static int