96522213/hw4

code/AST_Main.py

@@ -0,0 +1,40 @@
+from antlr4 import *
+import argparse
+from .Ast import ASTListener
+from .gen.MiniJavaLexer import MiniJavaLexer
+from .gen.MiniJavaParser import MiniJavaParser
+
+
+def main(args):
+    # Step 1: Load input source into stream
+    stream = FileStream(args.file, encoding='utf8')
+    print('Input code:\n{0}'.format(stream))
+    print('Result:')
+
+    # Step 2: Create an instance of AssignmentStLexer
+    lexer = MiniJavaLexer(stream)
+
+    # Step 3: Convert the input source into a list of tokens
+    token_stream = CommonTokenStream(lexer)
+
+    # Step 4: Create an instance of the AssignmentStParser
+    parser = MiniJavaParser(token_stream)
+
+    # Step 5: Create parse tree
+    parse_tree = parser.start()
+
+    # Step 6: Create an instance of AssignmentStListener
+    # code_generator_listener = ThreeAddressCodeGeneratorListener()
+    code_generator_listener = ASTListener()
+
+    # Step 7(a): Walk parse tree with a customized listener (Automatically)
+    walker = ParseTreeWalker()
+    walker.walk(t=parse_tree, listener=code_generator_listener)
+
+if __name__ == '__main__':
+    argparser = argparse.ArgumentParser()
+    argparser.add_argument(
+        '-n', '--file',
+        help='Input source', default=r'input.txt')
+    args = argparser.parse_args()
+    main(args)