Add new dev tool for the scope plugin (#193)

* Can show the result of scope analysis

* Better format

dev_tool/show_scope.py

@@ -0,0 +1,42 @@
+#!/usr/bin/env python
+
+import sys
+from argparse import ArgumentParser
+from pathlib import Path
+from pprint import pprint
+
+vint_root = Path(__file__).resolve().parent.parent
+sys.path.append(str(vint_root))
+
+from vint.ast.node_type import NodeType
+from vint.ast.traversing import traverse
+from vint.ast.parsing import Parser
+from vint.ast.plugin.scope_plugin import ScopePlugin
+
+
+def prettify_node_type(node):
+    node['type'] = NodeType(node['type'])
+
+
+if __name__ == '__main__':
+    arg_parser = ArgumentParser(prog='show_ast', description='Show AST')
+    arg_parser.add_argument('--enable-neovim', action='store_true', help='Enable Neovim syntax')
+    arg_parser.add_argument('files', nargs='*', help='File to parse')
+    namespace = vars(arg_parser.parse_args(sys.argv[1:]))
+
+    filepaths = map(Path, namespace['files'])
+    enable_neovim = namespace['enable_neovim']
+
+    scope_plugin = ScopePlugin()
+    parser = Parser(plugins={'scope': scope_plugin}, enable_neovim=enable_neovim)
+
+    for filepath in filepaths:
+        ast = parser.parse_file(filepath)
+        traverse(ast, on_enter=prettify_node_type)
+
+        print("////////// AST //////////\n")
+        pprint(ast)
+        print("\n\n")
+
+        print("////////// SCOPE TREE //////////\n")
+        pprint(scope_plugin._ref_tester._scope_tree)