Add recursive implementation of THEN.

include/boost/regex/v4/perl_matcher.hpp

@@ -509,6 +509,7 @@ private:
    // Set to false by a (*COMMIT):
    bool m_can_backtrack;
    bool m_have_accept;
+   bool m_have_then;
 #endif
 #ifdef BOOST_REGEX_NON_RECURSIVE
    //

include/boost/regex/v4/perl_matcher_recursive.hpp

@@ -60,7 +60,7 @@ public:
 template <class BidiIterator, class Allocator, class traits>
 bool perl_matcher<BidiIterator, Allocator, traits>::match_all_states()
 {
-   static matcher_proc_type const s_match_vtable[33] = 
+   static matcher_proc_type const s_match_vtable[34] = 
    {
       (&perl_matcher<BidiIterator, Allocator, traits>::match_startmark),
       &perl_matcher<BidiIterator, Allocator, traits>::match_endmark,
@@ -99,6 +99,7 @@ bool perl_matcher<BidiIterator, Allocator, traits>::match_all_states()
       &perl_matcher<BidiIterator, Allocator, traits>::match_fail,
       &perl_matcher<BidiIterator, Allocator, traits>::match_accept,
       &perl_matcher<BidiIterator, Allocator, traits>::match_commit,
+      &perl_matcher<BidiIterator, Allocator, traits>::match_then,
    };
 
    if(state_count > max_state_count)
@@ -155,6 +156,7 @@ bool perl_matcher<BidiIterator, Allocator, traits>::match_startmark()
          pstate = pstate->next.p->next.p;
          bool can_backtrack = m_can_backtrack;
          r = match_all_states();
+         if(r)
             m_can_backtrack = can_backtrack;
          pstate = next_pstate;
          m_independent = old_independent;
@@ -287,11 +289,19 @@ bool perl_matcher<BidiIterator, Allocator, traits>::match_alt()
          BidiIterator oldposition(position);
          const re_syntax_base* old_pstate = jmp->alt.p;
          pstate = pstate->next.p;
+         m_have_then = false;
          if(!match_all_states())
          {
             pstate = old_pstate;
             position = oldposition;
+            if(m_have_then)
+            {
+               m_can_backtrack = true;
+               m_have_then = false;
+               return false;
             }
+         }
+         m_have_then = false;
          return m_can_backtrack;
       }
       pstate = pstate->next.p;
@@ -1015,6 +1025,17 @@ bool perl_matcher<BidiIterator, Allocator, traits>::match_commit()
    return true;
 }
 
+template <class BidiIterator, class Allocator, class traits>
+bool perl_matcher<BidiIterator, Allocator, traits>::match_then()
+{
+   pstate = pstate->next.p;
+   if(match_all_states())
+      return true;
+   m_can_backtrack = false;
+   m_have_then = true;
+   return false;
+}
+
 template <class BidiIterator, class Allocator, class traits>
 bool perl_matcher<BidiIterator, Allocator, traits>::skip_until_paren(int index, bool match)
 {

test/regress/test_perl_ex.cpp

@@ -1000,63 +1000,4 @@ void test_verbs()
    TEST_REGEX_SEARCH("(?:a+(*THEN)\\w{6}|x\\w{3})", perl, "aaaxxxxx", match_default, make_array(3, 7, -2, -2));
    TEST_REGEX_SEARCH("(?>(*COMMIT)(?>yes|no)(*THEN)(*F))?", perl, "yes", match_default, make_array(-2, -2));
    TEST_REGEX_SEARCH("(?>(*COMMIT)(yes|no)(*THEN)(*F))?", perl, "yes", match_default, make_array(-2, -2));
-
-
-#if 0
-
-
-# Check the use of names for failure
-
-/^(A(*PRUNE:A)B|C(*PRUNE:B)D)/mark
-    ** Failers
-    AC
-    CB    
-    
-/(*MARK:A)(*SKIP:B)(C|X)/mark
-    C
-    D
-     
-/^(A(*THEN:A)B|C(*THEN:B)D)/mark
-    ** Failers
-    CB    
-
-/^(?:A(*THEN:A)B|C(*THEN:B)D)/mark
-    CB    
-    
-/^(?>A(*THEN:A)B|C(*THEN:B)D)/mark
-    CB    
-    
-# This should succeed, as the skip causes bump to offset 1 (the mark). Note
-# that we have to have something complicated such as (B|Z) at the end because,
-# for Perl, a simple character somehow causes an unwanted optimization to mess
-# with the handling of backtracking verbs.
-
-/A(*MARK:A)A+(*SKIP:A)(B|Z) | AC/x,mark
-    AAAC
-    
-# Test skipping over a non-matching mark.
-
-/A(*MARK:A)A+(*MARK:B)(*SKIP:A)(B|Z) | AC/x,mark
-    AAAC
-    
-# Check shorthand for MARK.
-
-/A(*:A)A+(*SKIP:A)(B|Z) | AC/x,mark
-    AAAC
-
-/(*:A)A+(*SKIP:A)(B|Z)/mark
-    AAAC
-
-# This should succeed, as a non-existent skip name disables the skip.
-
-/A(*MARK:A)A+(*SKIP:B)(B|Z) | AC/x,mark
-    AAAC
-
-/A(*MARK:A)A+(*SKIP:B)(B|Z) | AC(*:B)/x,mark
-    AAAC
-
-
-#endif
-
-
 }