RExC_parse++;
defchar: {
+ typedef enum {
+ char_s = 1,
+ upsilon_1,
+ upsilon_2,
+ iota_1,
+ iota_2,
+ } char_state;
+ char_state latest_char_state = 0;
register STRLEN len;
register UV ender;
register char *p;
* putting it in a special node keeps regexec from having to
* deal with a non-utf8 multi-char fold */
if (FOLD
- && (ender > 255 || (! MORE_ASCII_RESTRICTED && ! LOC))
- && is_TRICKYFOLD_cp(ender))
+ && (ender > 255 || (! MORE_ASCII_RESTRICTED && ! LOC)))
{
- /* If is in middle of outputting characters into an
- * EXACTish node, go output what we have so far, and
- * position the parse so that this will be called again
- * immediately */
- if (len) {
- p = oldp;
- goto loopdone;
- }
- else {
+ /* We look for either side of the fold. For example \xDF
+ * folds to 'ss'. We look for both the single character
+ * \xDF and the sequence 'ss'. When we find something that
+ * could be one of those, we stop and flush whatever we
+ * have output so far into the EXACTish node that was being
+ * built. Then restore the input pointer to what it was.
+ * regatom will return that EXACT node, and will be called
+ * again, positioned so the first character is the one in
+ * question, which we return in a different node type.
+ * The multi-char folds are a sequence, so the occurrence
+ * of the first character in that sequence doesn't
+ * necessarily mean that what follows is the rest of the
+ * sequence. We keep track of that with a state machine,
+ * with the state being set to the latest character
+ * processed before the current one. Most characters will
+ * set the state to 0, but if one occurs that is part of a
+ * potential tricky fold sequence, the state is set to that
+ * character, and the next loop iteration sees if the state
+ * should progress towards the final folded-from character,
+ * or if it was a false alarm. If it turns out to be a
+ * false alarm, the character(s) will be output in a new
+ * EXACTish node, and join_exact() will later combine them.
+ * In the case of the 'ss' sequence, which is more common
+ * and more easily checked, some look-ahead is done to
+ * save time by ruling-out some false alarms */
+ switch (ender) {
+ default:
+ latest_char_state = 0;
+ break;
+ case 's':
+ case 'S':
+ if (AT_LEAST_UNI_SEMANTICS) {
+ if (latest_char_state == char_s) { /* 'ss' */
+ ender = LATIN_SMALL_LETTER_SHARP_S;
+ goto do_tricky;
+ }
+ else if (p < RExC_end) {
+
+ /* Look-ahead at the next character. If it
+ * is also an s, we handle as a sharp s
+ * tricky regnode. */
+ if (*p == 's' || *p == 'S') {
+
+ /* But first flush anything in the
+ * EXACTish buffer */
+ if (len != 0) {
+ p = oldp;
+ goto loopdone;
+ }
+ p++; /* Account for swallowing this
+ 's' up */
+ ender = LATIN_SMALL_LETTER_SHARP_S;
+ goto do_tricky;
+ }
+ /* Here, the next character is not a
+ * literal 's', but still could
+ * evaluate to one if part of a \o{},
+ * \x or \OCTAL-DIGIT. The minimum
+ * length required for that is 4, eg
+ * \x53 or \123 */
+ else if (*p == '\\'
+ && p < RExC_end - 4
+ && (isDIGIT(*(p + 1))
+ || *(p + 1) == 'x'
+ || *(p + 1) == 'o' ))
+ {
+
+ /* Here, it could be an 's', too much
+ * bother to figure it out here. Flush
+ * the buffer if any; when come back
+ * here, set the state so know that the
+ * previous char was an 's' */
+ if (len != 0) {
+ latest_char_state = 0;
+ p = oldp;
+ goto loopdone;
+ }
+ latest_char_state = char_s;
+ break;
+ }
+ }
+ }
- /* Here we are ready to output our tricky fold
- * character. What's done is to pretend it's in a
- * [bracketed] class, and let the code that deals with
- * those handle it, as that code has all the
- * intelligence necessary. First save the current
- * parse state, get rid of the already allocated EXACT
- * node that the ANYOFV node will replace, and point
- * the parse to a buffer which we fill with the
- * character we want the regclass code to think is
- * being parsed */
- char* const oldregxend = RExC_end;
- char tmpbuf[2];
- RExC_emit = orig_emit;
- RExC_parse = tmpbuf;
- if (UTF) {
- tmpbuf[0] = UTF8_TWO_BYTE_HI(ender);
- tmpbuf[1] = UTF8_TWO_BYTE_LO(ender);
- RExC_end = RExC_parse + 2;
- }
- else {
- tmpbuf[0] = (char) ender;
- RExC_end = RExC_parse + 1;
- }
+ /* Here, can't be an 'ss' sequence, or at least not
+ * one that could fold to/from the sharp ss */
+ latest_char_state = 0;
+ break;
+ case 0x03C5: /* First char in upsilon series */
+ if (p < RExC_end - 4) { /* Need >= 4 bytes left */
+ latest_char_state = upsilon_1;
+ if (len != 0) {
+ p = oldp;
+ goto loopdone;
+ }
+ }
+ else {
+ latest_char_state = 0;
+ }
+ break;
+ case 0x03B9: /* First char in iota series */
+ if (p < RExC_end - 4) {
+ latest_char_state = iota_1;
+ if (len != 0) {
+ p = oldp;
+ goto loopdone;
+ }
+ }
+ else {
+ latest_char_state = 0;
+ }
+ break;
+ case 0x0308:
+ if (latest_char_state == upsilon_1) {
+ latest_char_state = upsilon_2;
+ }
+ else if (latest_char_state == iota_1) {
+ latest_char_state = iota_2;
+ }
+ else {
+ latest_char_state = 0;
+ }
+ break;
+ case 0x301:
+ if (latest_char_state == upsilon_2) {
+ ender = GREEK_SMALL_LETTER_UPSILON_WITH_DIALYTIKA_AND_TONOS;
+ goto do_tricky;
+ }
+ else if (latest_char_state == iota_2) {
+ ender = GREEK_SMALL_LETTER_IOTA_WITH_DIALYTIKA_AND_TONOS;
+ goto do_tricky;
+ }
+ latest_char_state = 0;
+ break;
- ret = regclass(pRExC_state,depth+1);
+ /* These are the tricky fold characters. Flush any
+ * buffer first. */
+ case GREEK_SMALL_LETTER_UPSILON_WITH_DIALYTIKA_AND_TONOS:
+ case GREEK_SMALL_LETTER_IOTA_WITH_DIALYTIKA_AND_TONOS:
+ case LATIN_SMALL_LETTER_SHARP_S:
+ case LATIN_CAPITAL_LETTER_SHARP_S:
+ case 0x1FD3:
+ case 0x1FE3:
+ if (len != 0) {
+ p = oldp;
+ goto loopdone;
+ }
+ /* FALL THROUGH */
+ do_tricky: {
+ char* const oldregxend = RExC_end;
+ U8 tmpbuf[UTF8_MAXBYTES+1];
+
+ /* Here, we know we need to generate a special
+ * regnode, and 'ender' contains the tricky
+ * character. What's done is to pretend it's in a
+ * [bracketed] class, and let the code that deals
+ * with those handle it, as that code has all the
+ * intelligence necessary. First save the current
+ * parse state, get rid of the already allocated
+ * but empty EXACT node that the ANYOFV node will
+ * replace, and point the parse to a buffer which
+ * we fill with the character we want the regclass
+ * code to think is being parsed */
+ RExC_emit = orig_emit;
+ RExC_parse = (char *) tmpbuf;
+ if (UTF) {
+ U8 *d = uvchr_to_utf8(tmpbuf, ender);
+ *d = '\0';
+ RExC_end = (char *) d;
+ }
+ else {
+ tmpbuf[0] = ender;
+ tmpbuf[1] = '\0';
+ RExC_end = RExC_parse + 1;
+ }
- /* Here, have parsed the buffer. Reset the parse to
- * the actual input, and return */
- RExC_end = oldregxend;
- RExC_parse = p - 1;
+ ret = regclass(pRExC_state,depth+1);
- Set_Node_Offset(ret, RExC_parse);
- Set_Node_Cur_Length(ret);
- nextchar(pRExC_state);
- *flagp |= HASWIDTH|SIMPLE;
- return ret;
+ /* Here, have parsed the buffer. Reset the parse to
+ * the actual input, and return */
+ RExC_end = oldregxend;
+ RExC_parse = p - 1;
+
+ Set_Node_Offset(ret, RExC_parse);
+ Set_Node_Cur_Length(ret);
+ nextchar(pRExC_state);
+ *flagp |= HASWIDTH|SIMPLE;
+ return ret;
+ }
}
}
}
len--;
}
- else
+ else {
REGC((char)ender, s++);
+ }
}
loopdone: /* Jumped to when encounters something that shouldn't be in
the node */
projects / platform / upstream / perl.git / commitdiff