tighten up error checking in Regex.sub()

1 files changed, 17 insertions, 1 deletions

diff --git a/pyparsing.py b/pyparsing.py
index cdbf398..3ea7660 100644
--- a/pyparsing.py
+++ b/pyparsing.py
@@ -2846,7 +2846,23 @@ class Regex(Token):
         Return Regex with an attached parse action to transform the parsed

         result as if called using C{re.sub(expr, repl, string)}.

         """

-        return self.addParseAction(lambda s, l, t: self.re.sub(repl, t[0]))

+        if self.asGroupList:

+            warnings.warn("cannot use sub() with Regex(asGroupList=True)", 

+                           SyntaxWarning, stacklevel=2)

+            raise SyntaxError()

+

+        if self.asMatch and callable(repl):

+            warnings.warn("cannot use sub() with a callable with Regex(asMatch=True)", 

+                           SyntaxWarning, stacklevel=2)

+            raise SyntaxError()        

+

+        if self.asMatch:

+            def pa(tokens):

+                return tokens[0].expand(repl)

+        else:

+            def pa(tokens):

+                return self.re.sub(repl, tokens[0])

+        return self.addParseAction(pa)

 

 class QuotedString(Token):

     r"""