Add regex input to regex_to_nfa.py and regex_to_regex.py

regex_to_nfa.py

@@ -1,5 +1,8 @@
-from regex import Literal, Concatenation, Alternation, Star, lit, concat, bar, star
+import sys
+
+from regex import Literal, Concatenation, Alternation, Star, lit
 from nfa import NFA, prettyprint
+from parse_regex import parse, ParseError
 
 def to_nfa(regex):
 	def new_state():
@@ -94,12 +97,16 @@ def to_nfa(regex):
 	return NFA(start_state, [end_state], transitions)
 
 def main():
-	regex = concat(lit('x'), star(bar(lit('a'), lit('b'))), lit('y'))
-	print(regex)
+	try:
+		regex = parse(input('regex> '))
 
-	nfa = to_nfa(regex)
+	except ParseError as err:
+		print('%s: Error: %s' % (sys.argv[0], str(err)), file=sys.stderr)
 
-	prettyprint(nfa)
+	else:
+		nfa = to_nfa(regex)
+
+		prettyprint(nfa)
 
 if __name__ == '__main__':
 	main()

regex_to_regex.py

@@ -1,15 +1,21 @@
-from regex import lit, concat, bar, star
+import sys
+
 from regex_to_nfa import to_nfa
 from nfa_to_regex import to_regex
+from parse_regex import parse, ParseError
 
 def main():
-	regex = concat(bar(lit('foo'), lit('bar')), bar(lit('baz'), lit('qux')))
-	print(regex)
+	try:
+		regex = parse(input('regex> '))
 
-	nfa = to_nfa(regex)
-	regex_prime = to_regex(nfa)
+	except ParseError as err:
+		print('%s: Error: %s' % (sys.argv[0], str(err)), file=sys.stderr)
 
-	print(regex_prime)
+	else:
+		nfa = to_nfa(regex)
+		regex_prime = to_regex(nfa)
+
+		print(regex_prime)
 
 if __name__ == '__main__':
 	main()