Get THEN working for non-recursive implementation.

Fix various bugs in the other verbs exposed by new tests.

include/boost/regex/v4/basic_regex_parser.hpp

@@ -2815,6 +2815,31 @@ bool basic_regex_parser<charT, traits>::parse_perl_verb()
          return true;
       }
       break;
+   case 'T':
+      if(++m_position == m_end)
+      {
+         // Rewind to start of (* sequence:
+         --m_position;
+         while(this->m_traits.syntax_type(*m_position) != regex_constants::syntax_open_mark) --m_position;
+         fail(regex_constants::error_perl_extension, m_position - m_base);
+         return false;
+      }
+      if(match_verb("HEN"))
+      {
+         if((m_position == m_end) || (this->m_traits.syntax_type(*m_position) != regex_constants::syntax_close_mark))
+         {
+            // Rewind to start of (* sequence:
+            --m_position;
+            while(this->m_traits.syntax_type(*m_position) != regex_constants::syntax_open_mark) --m_position;
+            fail(regex_constants::error_perl_extension, m_position - m_base);
+            return false;
+         }
+         ++m_position;
+         this->append_state(syntax_element_then);
+         this->m_pdata->m_disable_match_any = true;
+         return true;
+      }
+      break;
    }
    return false;
 }

include/boost/regex/v4/perl_matcher.hpp

@@ -446,6 +446,7 @@ private:
    bool match_fail();
    bool match_accept();
    bool match_commit();
+   bool match_then();
    bool skip_until_paren(int index, bool match = true);
 
    // find procs stored in s_find_vtable:
@@ -534,6 +535,7 @@ private:
    bool unwind_recursion(bool);
    bool unwind_recursion_pop(bool);
    bool unwind_commit(bool);
+   bool unwind_then(bool);
    void destroy_single_repeat();
    void push_matched_paren(int index, const sub_match<BidiIterator>& sub);
    void push_recursion_stopper();
@@ -549,13 +551,17 @@ private:
    saved_state* m_stack_base;
    // pointer to current stack position:
    saved_state* m_backup_state;
+   // how many memory blocks have we used up?:
+   unsigned used_block_count;
    // determines what value to return when unwinding from recursion,
    // allows for mixed recursive/non-recursive algorithm:
    bool m_recursive_result;
-   // how many memory blocks have we used up?:
-   unsigned used_block_count;
    // We have unwound to a lookahead/lookbehind, used by COMMIT/PRUNE/SKIP:
    bool m_unwound_lookahead;
+   // We have unwound to an alternative, used by THEN:
+   bool m_unwound_alt;
+   // We are unwinding a commit - used by independent subs to determine whether to stop there or carry on unwinding:
+   //bool m_unwind_commit;
 #endif
 
    // these operations aren't allowed, so are declared private,

include/boost/regex/v4/perl_matcher_non_recursive.hpp

@@ -141,7 +141,7 @@ struct saved_recursion : public saved_state
 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,
@@ -180,6 +180,7 @@ 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,
    };
 
    push_recursion_stopper();
@@ -373,6 +374,13 @@ bool perl_matcher<BidiIterator, Allocator, traits>::match_startmark()
          const re_syntax_base* next_pstate = static_cast<const re_jump*>(pstate->next.p)->alt.p->next.p;
          pstate = pstate->next.p->next.p;
          bool r = match_all_states();
+         if(!r && !m_independent)
+         {
+            // Must be unwinding from a COMMIT/SKIP/PRUNE and the independent 
+            // sub failed, need to unwind everything else:
+            while(unwind(false));
+            return false;
+         }
          pstate = next_pstate;
          m_independent = old_independent;
 #ifdef BOOST_REGEX_MATCH_EXTRA
@@ -1018,16 +1026,13 @@ bool perl_matcher<BidiIterator, Allocator, traits>::match_commit()
    switch(static_cast<const re_commit*>(pstate)->action)
    {
    case commit_commit:
-      if(base != last)
-      {
-         restart = last;
-         --restart;
-      }
+      restart = last;
       break;
    case commit_skip:
-      if(position != base)
+      if(base != position)
       {
          restart = position;
+         // Have to decrement restart since it will get incremented again later:
          --restart;
       }
       break;
@@ -1049,6 +1054,24 @@ 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()
+{
+   // Just leave a mark that we need to skip to next alternative:
+   saved_state* pmp = m_backup_state;
+   --pmp;
+   if(pmp < m_stack_base)
+   {
+      extend_stack();
+      pmp = m_backup_state;
+      --pmp;
+   }
+   (void) new (pmp)saved_state(17);
+   m_backup_state = pmp;
+   pstate = pstate->next.p;
+   return true;
+}
+
 template <class BidiIterator, class Allocator, class traits>
 bool perl_matcher<BidiIterator, Allocator, traits>::skip_until_paren(int index, bool match)
 {
@@ -1099,7 +1122,7 @@ unwinding does in the recursive implementation.
 template <class BidiIterator, class Allocator, class traits>
 bool perl_matcher<BidiIterator, Allocator, traits>::unwind(bool have_match)
 {
-   static unwind_proc_type const s_unwind_table[18] = 
+   static unwind_proc_type const s_unwind_table[19] = 
    {
       &perl_matcher<BidiIterator, Allocator, traits>::unwind_end,
       &perl_matcher<BidiIterator, Allocator, traits>::unwind_paren,
@@ -1118,10 +1141,12 @@ bool perl_matcher<BidiIterator, Allocator, traits>::unwind(bool have_match)
       &perl_matcher<BidiIterator, Allocator, traits>::unwind_recursion,
       &perl_matcher<BidiIterator, Allocator, traits>::unwind_recursion_pop,
       &perl_matcher<BidiIterator, Allocator, traits>::unwind_commit,
+      &perl_matcher<BidiIterator, Allocator, traits>::unwind_then,
    };
 
    m_recursive_result = have_match;
    m_unwound_lookahead = false;
+   m_unwound_alt = false;
    unwind_proc_type unwinder;
    bool cont;
    //
@@ -1201,6 +1226,7 @@ bool perl_matcher<BidiIterator, Allocator, traits>::unwind_alt(bool r)
    }
    boost::BOOST_REGEX_DETAIL_NS::inplace_destroy(pmp++);
    m_backup_state = pmp;
+   m_unwound_alt = !r;
    return r; 
 }
 
@@ -1692,6 +1718,22 @@ bool perl_matcher<BidiIterator, Allocator, traits>::unwind_commit(bool b)
       (void) new (pmp)saved_state(16);
       m_backup_state = pmp;
    }
+   // This prevents us from stopping when we exit from an independent sub-expression:
+   m_independent = false;
+   return false;
+}
+
+template <class BidiIterator, class Allocator, class traits>
+bool perl_matcher<BidiIterator, Allocator, traits>::unwind_then(bool b)
+{
+   // Unwind everything till we hit an alternative:
+   boost::BOOST_REGEX_DETAIL_NS::inplace_destroy(m_backup_state++);
+   bool result = false;
+   while((result = unwind(b)) && !m_unwound_alt){}
+   // We're now pointing at the next alternative, need one more backtrack 
+   // since *all* the other alternatives must fail once we've reached a THEN clause:
+   if(result && m_unwound_alt)
+      unwind(b);
    return false;
 }
 

include/boost/regex/v4/states.hpp

@@ -125,6 +125,7 @@ enum syntax_element_type
    syntax_element_fail = syntax_element_recurse + 1,
    syntax_element_accept = syntax_element_fail + 1,
    syntax_element_commit = syntax_element_accept + 1,
+   syntax_element_then = syntax_element_commit + 1,
 };
 
 #ifdef BOOST_REGEX_DEBUG