add empty parserules module, add parser.parse() method

parser/__init__.py

@@ -0,0 +1,11 @@
+
+import ply.lex as lex
+import ply.yacc as yacc
+import lexrules
+import parserules
+
+def parse(input):
+    lexer = lex.lex(module = lexrules)
+    parser = yacc.yacc(module = parserules)
+    result = parser.parse(input)
+    return result

parser/parserules.py

@@ -0,0 +1,2 @@
+
+from lexrules import tokens