Initial MATCH_WHOLE_STRING Implementation

This new search option aims to ensure that the pattern matches the whole
input string. To bse used to imepement an `is_match` check.

doc/API

@@ -407,7 +407,7 @@ Oniguruma API  Version 6.9.7  2021/03/03
     ONIG_OPTION_NOT_END_STRING      Do not regard the (end) as a string endpoint  (* fail \z, \Z)
     ONIG_OPTION_NOT_BEGIN_POSITION  Do not regard the (start) as start position of search  (* fail \G)
     ONIG_OPTION_CALLBACK_EACH_MATCH Call back for all successful matches.
-
+    ONIG_OPTION_MATCH_WHOLE_STRING  Try to match the whole of (str), rather than returning after the first match is found.
 
 # int onig_match_with_param(regex_t* reg, const UChar* str, const UChar* end,
                             const UChar* at, OnigRegion* region,

src/oniguruma.h

@@ -401,8 +401,9 @@ typedef unsigned int        OnigOptionType;
 #define ONIG_OPTION_NOT_END_STRING       (ONIG_OPTION_NOT_BEGIN_STRING << 1)
 #define ONIG_OPTION_NOT_BEGIN_POSITION   (ONIG_OPTION_NOT_END_STRING << 1)
 #define ONIG_OPTION_CALLBACK_EACH_MATCH  (ONIG_OPTION_NOT_BEGIN_POSITION << 1)
+#define ONIG_OPTION_MATCH_WHOLE_STRING   (ONIG_OPTION_CALLBACK_EACH_MATCH << 1)
 
-#define ONIG_OPTION_MAXBIT               ONIG_OPTION_CALLBACK_EACH_MATCH
+#define ONIG_OPTION_MAXBIT               ONIG_OPTION_MATCH_WHOLE_STRING
 
 #define ONIG_OPTION_ON(options,regopt)      ((options) |= (regopt))
 #define ONIG_OPTION_OFF(options,regopt)     ((options) &= ~(regopt))

src/regexec.c

@@ -3155,6 +3155,14 @@ match_at(regex_t* reg, const UChar* str, const UChar* end,
         goto fail;
       }
 
+      // FIXME: This doesn't solve the issue. Properly implement backtracking
+      //        to find longest match in whole string. Do we need to introduce
+      //        a phony acnhor at the end of the string?
+      if (OPTON_MATCH_WHOLE_STRING(options)) {
+        best_len = ONIG_MISMATCH;
+        goto fail;
+      }
+
       /* default behavior: return first-matching result. */
       goto match_at_end;
 
@@ -5459,7 +5467,6 @@ search_in_range(regex_t* reg, const UChar* str, const UChar* end,
     else goto finish; /* error */ \
   }
 
-
   /* anchor optimize: resume search range */
   if (reg->anchor != 0 && str < end) {
     UChar *min_semi_end, *max_semi_end;

src/regint.h

@@ -408,6 +408,7 @@ typedef unsigned int  MemStatusType;
 #define OPTON_NOT_BEGIN_STRING(option)    ((option) & ONIG_OPTION_NOT_BEGIN_STRING)
 #define OPTON_NOT_END_STRING(option)      ((option) & ONIG_OPTION_NOT_END_STRING)
 #define OPTON_NOT_BEGIN_POSITION(option)  ((option) & ONIG_OPTION_NOT_BEGIN_POSITION)
+#define OPTON_MATCH_WHOLE_STRING(option)  ((option) & ONIG_OPTION_MATCH_WHOLE_STRING)
 
 
 #define INFINITE_REPEAT         -1

test/test_options.c

@@ -197,6 +197,10 @@ extern int main(int argc, char* argv[])
   n(ONIG_OPTION_NOT_END_STRING, "ab\\Z", "ab");
   n(ONIG_OPTION_NOT_END_STRING, "ab\\Z", "ab\n");
 
+  x2(ONIG_OPTION_NONE, "a|abc", "abc", 0, 1);
+  x2(ONIG_OPTION_NONE, "(a|abc)\\Z", "abc", 0, 3);
+  x2(ONIG_OPTION_MATCH_WHOLE_STRING, "a|abc", "abc", 0, 3);
+
   x2(ONIG_OPTION_WORD_IS_ASCII, "\\w", "@g", 1, 2);
   n(ONIG_OPTION_WORD_IS_ASCII, "\\w", "あ");
   x2(ONIG_OPTION_NONE, "\\d", "１", 0, 3);
@@ -219,6 +223,5 @@ extern int main(int argc, char* argv[])
 
   onig_region_free(region, 1);
   onig_end();
-
   return ((nfail == 0 && nerror == 0) ? 0 : -1);
 }