mruby-regexp: rename has_nongreedy to needs_backtrack

The flag is set not only for non-greedy quantifiers but also for
lookahead, lookbehind, and backreferences. The new name accurately
reflects its purpose: indicating that the backtracking engine is
required instead of the Pike VM.

Co-authored-by: Claude <noreply@anthropic.com>

mrbgems/mruby-regexp/include/re_internal.h

@@ -69,7 +69,7 @@ typedef struct mrb_regexp_pattern {
   re_named_capture *named_captures;
   uint16_t num_named;
   mrb_bool has_backref;    /* true if pattern uses \1-\9 */
-  mrb_bool has_nongreedy;  /* true if pattern uses *?, +?, ?? */
+  mrb_bool needs_backtrack; /* true if pattern needs backtracking engine */
 } mrb_regexp_pattern;
 
 /* Regexp flags */

mrbgems/mruby-regexp/src/re_compile.c

@@ -28,7 +28,7 @@ typedef struct {
   re_named_capture *named_captures;
   uint16_t num_named;
   mrb_bool has_backref;
-  mrb_bool has_nongreedy;
+  mrb_bool needs_backtrack;
   char *stripped;           /* allocated buffer for x-mode preprocessing */
 } re_compiler;
 
@@ -365,7 +365,7 @@ compile_atom(re_compiler *c)
           c->code[la_pos].offset = (uint16_t)c->code_len;  /* patch: skip past sub-pattern */
           if (peek(c) != ')') compile_error(c, "unmatched '('");
           next_char(c);
-          c->has_nongreedy = TRUE;  /* needs backtracking engine */
+          c->needs_backtrack = TRUE;  /* needs backtracking engine */
           break;  /* done with this atom */
         }
         else if (c->p[1] == '<' && c->p + 2 < c->src_end && (c->p[2] == '=' || c->p[2] == '!')) {
@@ -390,7 +390,7 @@ compile_atom(re_compiler *c)
 
           if (peek(c) != ')') compile_error(c, "unmatched '('");
           next_char(c);
-          c->has_nongreedy = TRUE;  /* needs backtracking engine */
+          c->needs_backtrack = TRUE;  /* needs backtracking engine */
           break;
         }
         else if (c->p[1] == '<' && c->p + 2 < c->src_end && c->p[2] != '=' && c->p[2] != '!') {
@@ -548,7 +548,7 @@ compile_quantified(re_compiler *c)
     mrb_bool nongreedy = (peek(c) == '?');
     if (nongreedy) {
       next_char(c);
-      c->has_nongreedy = TRUE;
+      c->needs_backtrack = TRUE;
     }
 
 
@@ -582,7 +582,7 @@ compile_quantified(re_compiler *c)
     mrb_bool nongreedy = (peek(c) == '?');
     if (nongreedy) {
       next_char(c);
-      c->has_nongreedy = TRUE;
+      c->needs_backtrack = TRUE;
     }
 
     /* For {n,m}: repeat atom min times, then optional (max-min) times */
@@ -774,7 +774,7 @@ re_compile(mrb_state *mrb, const char *pattern, mrb_int len, uint32_t flags)
   pat->named_captures = c.named_captures;
   pat->num_named = c.num_named;
   pat->has_backref = c.has_backref;
-  pat->has_nongreedy = c.has_nongreedy;
+  pat->needs_backtrack = c.needs_backtrack;
 
   if (c.stripped) mrb_free(mrb, c.stripped);
   return pat;

mrbgems/mruby-regexp/src/re_exec.c

@@ -515,7 +515,7 @@ re_exec(mrb_state *mrb, const mrb_regexp_pattern *pat,
         const char *str, mrb_int len, mrb_int start,
         int *captures, int captures_size)
 {
-  if (pat->has_backref || pat->has_nongreedy) {
+  if (pat->has_backref || pat->needs_backtrack) {
     return backtrack_exec(mrb, pat, str, len, start, captures, captures_size);
   }
   return pike_vm(mrb, pat, str, len, start, captures, captures_size);