parser-combinators: added <!?>

diff --git a/libs/parser-combinators/parser-combinators.factor b/libs/parser-combinators/parser-combinators.factor
index 39ba92807cd8c33180bb63a4e1c6334497773ff0..82af77c9c4d9e7bdd0130a0ace1a47a4325663a3 100644 (file)
--- a/libs/parser-combinators/parser-combinators.factor
+++ b/libs/parser-combinators/parser-combinators.factor
@@ -221,3 +221,11 @@ LAZY: <!+> ( parser -- parser )
   #! usually the effect you want and cuts down on backtracking
   #! required.
   <+> only-first ;
+
+LAZY: <!?> ( parser -- parser )
+  #! Like <?> but only return one possible result
+  #! containing all matching parses. Does not return
+  #! partial matches. Useful for efficiency since that's
+  #! usually the effect you want and cuts down on backtracking
+  #! required.
+  <?> only-first ;