squeeze!(*args)
public
Squeezes str in place, returning either str, or nil if no
changes were made.
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static VALUE
rb_str_squeeze_bang(int argc, VALUE *argv, VALUE str)
{
char squeez[256];
rb_encoding *enc = 0;
VALUE del = 0, nodel = 0;
char *s, *send, *t;
int i, modify = 0;
int ascompat, singlebyte = single_byte_optimizable(str);
unsigned int save;
if (argc == 0) {
enc = STR_ENC_GET(str);
}
else {
for (i=0; i<argc; i++) {
VALUE s = argv[i];
StringValue(s);
enc = rb_enc_check(str, s);
if (singlebyte && !single_byte_optimizable(s))
singlebyte = 0;
tr_setup_table(s, squeez, i==0, &del, &nodel, enc);
}
}
str_modify_keep_cr(str);
s = t = RSTRING_PTR(str);
if (!s || RSTRING_LEN(str) == 0) return Qnil;
send = RSTRING_END(str);
save = -1;
ascompat = rb_enc_asciicompat(enc);
if (singlebyte) {
while (s < send) {
unsigned int c = *(unsigned char*)s++;
if (c != save || (argc > 0 && !squeez[c])) {
*t++ = save = c;
}
}
} else {
while (s < send) {
unsigned int c;
int clen;
if (ascompat && (c = *(unsigned char*)s) < 0x80) {
if (c != save || (argc > 0 && !squeez[c])) {
*t++ = save = c;
}
s++;
}
else {
c = rb_enc_codepoint_len(s, send, &clen, enc);
if (c != save || (argc > 0 && !tr_find(c, squeez, del, nodel))) {
if (t != s) rb_enc_mbcput(c, t, enc);
save = c;
t += clen;
}
s += clen;
}
}
}
*t = '\0';
if (t - RSTRING_PTR(str) != RSTRING_LEN(str)) {
STR_SET_LEN(str, t - RSTRING_PTR(str));
modify = 1;
}
if (modify) return str;
return Qnil;
}