Perl__swash_inversion_hash(pTHX_ SV* const swash)
{
- /* Subject to change or removal. For use only in one place in regexec.c
+ /* Subject to change or removal. For use only in one place in regcomp.c.
+ * Can't be used on a property that is subject to user override, as it
+ * relies on the value of SPECIALS in the swash which would be set by
+ * utf8_heavy.pl to the hash in the non-overriden file, and hence is not set
+ * for overridden properties
*
* Returns a hash which is the inversion and closure of a swash mapping.
* For example, consider the input lines:
* Essentially, for any code point, it gives all the code points that map to
* it, or the list of 'froms' for that point.
*
- * Currently it only looks at the main body of the swash, and ignores any
- * additions or deletions from other swashes */
+ * Currently it ignores any additions or deletions from other swashes,
+ * looking at just the main body of the swash, and if there are SPECIALS
+ * in the swash, at that hash
+ *
+ * The specials hash can be extra code points, and most likely consists of
+ * maps from single code points to multiple ones (each expressed as a string
+ * of utf8 characters). This function currently returns only 1-1 mappings.
+ * However consider this possible input in the specials hash:
+ * "\xEF\xAC\x85" => "\x{0073}\x{0074}", # U+FB05 => 0073 0074
+ * "\xEF\xAC\x86" => "\x{0073}\x{0074}", # U+FB06 => 0073 0074
+ *
+ * Both FB05 and FB06 map to the same multi-char sequence, which we don't
+ * currently handle. But it also means that FB05 and FB06 are equivalent in
+ * a 1-1 mapping which we should handle, and this relationship may not be in
+ * the main table. Therefore this function examines all the multi-char
+ * sequences and adds the 1-1 mappings that come out of that. */
U8 *l, *lend;
STRLEN lcur;
const STRLEN bits = SvUV(*bitssvp);
const STRLEN octets = bits >> 3; /* if bits == 1, then octets == 0 */
const UV none = SvUV(*nonesvp);
+ SV **specials_p = hv_fetchs(hv, "SPECIALS", 0);
HV* ret = newHV();
(UV)bits);
}
+ if (specials_p) { /* It might be "special" (sometimes, but not always, a
+ mapping to more than one character */
+
+ /* Construct an inverse mapping hash for the specials */
+ HV * const specials_hv = MUTABLE_HV(SvRV(*specials_p));
+ HV * specials_inverse = newHV();
+ char *char_from; /* the lhs of the map */
+ I32 from_len; /* its byte length */
+ char *char_to; /* the rhs of the map */
+ I32 to_len; /* its byte length */
+ SV *sv_to; /* and in a sv */
+ AV* from_list; /* list of things that map to each 'to' */
+
+ hv_iterinit(specials_hv);
+
+ /* The keys are the characters (in utf8) that map to the corresponding
+ * utf8 string value. Iterate through the list creating the inverse
+ * list. */
+ while ((sv_to = hv_iternextsv(specials_hv, &char_from, &from_len))) {
+ SV** listp;
+ if (! SvPOK(sv_to)) {
+ Perl_croak(aTHX_ "panic: value returned from hv_iternextsv() unexpectedly is not a string");
+ }
+ /*DEBUG_U(PerlIO_printf(Perl_debug_log, "Found mapping from %"UVXf", First char of to is %"UVXf"\n", utf8_to_uvchr((U8*) char_from, 0), utf8_to_uvchr((U8*) SvPVX(sv_to), 0)));*/
+
+ /* Each key in the inverse list is a mapped-to value, and the key's
+ * hash value is a list of the strings (each in utf8) that map to
+ * it. Those strings are all one character long */
+ if ((listp = hv_fetch(specials_inverse,
+ SvPVX(sv_to),
+ SvCUR(sv_to), 0)))
+ {
+ from_list = (AV*) *listp;
+ }
+ else { /* No entry yet for it: create one */
+ from_list = newAV();
+ if (! hv_store(specials_inverse,
+ SvPVX(sv_to),
+ SvCUR(sv_to),
+ (SV*) from_list, 0))
+ {
+ Perl_croak(aTHX_ "panic: hv_store() unexpectedly failed");
+ }
+ }
+
+ /* Here have the list associated with this 'to' (perhaps newly
+ * created and empty). Just add to it. Note that we ASSUME that
+ * the input is guaranteed to not have duplications, so we don't
+ * check for that. Duplications just slow down execution time. */
+ av_push(from_list, newSVpvn_utf8(char_from, from_len, TRUE));
+ }
+
+ /* Here, 'specials_inverse' contains the inverse mapping. Go through
+ * it looking for cases like the FB05/FB06 examples above. There would
+ * be an entry in the hash like
+ * 'st' => [ FB05, FB06 ]
+ * In this example we will create two lists that get stored in the
+ * returned hash, 'ret':
+ * FB05 => [ FB05, FB06 ]
+ * FB06 => [ FB05, FB06 ]
+ *
+ * Note that there is nothing to do if the array only has one element.
+ * (In the normal 1-1 case handled below, we don't have to worry about
+ * two lists, as everything gets tied to the single list that is
+ * generated for the single character 'to'. But here, we are omitting
+ * that list, ('st' in the example), so must have multiple lists.) */
+ while ((from_list = (AV *) hv_iternextsv(specials_inverse,
+ &char_to, &to_len)))
+ {
+ if (av_len(from_list) > 0) {
+ int i;
+
+ /* We iterate over all combinations of i,j to place each code
+ * point on each list */
+ for (i = 0; i <= av_len(from_list); i++) {
+ int j;
+ AV* i_list = newAV();
+ SV** entryp = av_fetch(from_list, i, FALSE);
+ if (entryp == NULL) {
+ Perl_croak(aTHX_ "panic: av_fetch() unexpectedly failed");
+ }
+ if (hv_fetch(ret, SvPVX(*entryp), SvCUR(*entryp), FALSE)) {
+ Perl_croak(aTHX_ "panic: unexpected entry for %s", SvPVX(*entryp));
+ }
+ if (! hv_store(ret, SvPVX(*entryp), SvCUR(*entryp),
+ (SV*) i_list, FALSE))
+ {
+ Perl_croak(aTHX_ "panic: hv_store() unexpectedly failed");
+ }
+
+ /* For debugging: UV u = utf8_to_uvchr((U8*) SvPVX(*entryp), 0);*/
+ for (j = 0; j <= av_len(from_list); j++) {
+ entryp = av_fetch(from_list, j, FALSE);
+ if (entryp == NULL) {
+ Perl_croak(aTHX_ "panic: av_fetch() unexpectedly failed");
+ }
+
+ /* When i==j this adds itself to the list */
+ av_push(i_list, newSVuv(utf8_to_uvchr(
+ (U8*) SvPVX(*entryp), 0)));
+ /*DEBUG_U(PerlIO_printf(Perl_debug_log, "Adding %"UVXf" to list for %"UVXf"\n", utf8_to_uvchr((U8*) SvPVX(*entryp), 0), u));*/
+ }
+ }
+ }
+ }
+ SvREFCNT_dec(specials_inverse); /* done with it */
+ } /* End of specials */
+
/* read $swash->{LIST} */
l = (U8*)SvPV(*listsvp, lcur);
lend = l + lcur;
SV** listp;
IV i;
bool found_key = FALSE;
+ bool found_inverse = FALSE;
/* The key is the inverse mapping */
char key[UTF8_MAXBYTES+1];
}
}
+ /* Look through list to see if this inverse mapping already is
+ * listed, or if there is a mapping to itself already */
for (i = 0; i <= av_len(list); i++) {
SV** entryp = av_fetch(list, i, FALSE);
SV* entry;
Perl_croak(aTHX_ "panic: av_fetch() unexpectedly failed");
}
entry = *entryp;
+ /*DEBUG_U(PerlIO_printf(Perl_debug_log, "list for %"UVXf" contains %"UVXf"\n", val, SvUV(entry)));*/
if (SvUV(entry) == val) {
found_key = TRUE;
+ }
+ if (SvUV(entry) == inverse) {
+ found_inverse = TRUE;
+ }
+
+ /* No need to continue searching if found everything we are
+ * looking for */
+ if (found_key && found_inverse) {
break;
}
}
/* Make sure there is a mapping to itself on the list */
if (! found_key) {
av_push(list, newSVuv(val));
+ /*DEBUG_U(PerlIO_printf(Perl_debug_log, "Adding %"UVXf" to list for %"UVXf"\n", val, val));*/
}
/* Simply add the value to the list */
- av_push(list, newSVuv(inverse));
+ if (! found_inverse) {
+ av_push(list, newSVuv(inverse));
+ /*DEBUG_U(PerlIO_printf(Perl_debug_log, "Adding %"UVXf" to list for %"UVXf"\n", inverse, val));*/
+ }
/* swash_get() increments the value of val for each element in the
* range. That makes more compact tables possible. You can
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