support +

1 files changed, 8 insertions, 1 deletions

diff --git a/parsers.py b/parsers.py
index 8427137..c851647 100644
--- a/parsers.py
+++ b/parsers.py
@@ -103,6 +103,13 @@ def _regex_to_ast(tokens):
         else:
             return ('CONCAT', _regex_to_ast(tokens[:-2]),
                     ('KLEENE', _regex_to_ast(tokens[-2:-1])))
+    if tokens[-1] == '+':
+        arg_ast = _regex_to_ast(tokens[:-1])
+        if len(tokens) == 2:
+            return ('CONCAT', arg_ast, ('KLEENE', arg_ast))
+        else:
+            return ('CONCAT', _regex_to_ast(tokens[:-2]),
+                    ('CONCAT', arg_ast, ('KLEENE', _regex_to_ast(tokens[-2:-1]))))
     return ('CONCAT', _regex_to_ast(tokens[:-1]), _regex_to_ast(tokens[-1:]))
 
 def match_parens(tokens):
@@ -124,7 +131,7 @@ def lex_regex(string):
     while string:
         if string[0].isspace():
             string = string[1:]
-        elif string[0] in ("(", ")", "|", "*") + ALPHABET:
+        elif string[0] in ("(", ")", "|", "*", "+") + ALPHABET:
             tokens.append(string[0])
             string = string[1:]
         elif string[0] == "E":