Current Path : /lib64/python2.7/compiler/ |
Current File : //lib64/python2.7/compiler/future.py |
"""Parser for future statements """ from compiler import ast, walk def is_future(stmt): """Return true if statement is a well-formed future statement""" if not isinstance(stmt, ast.From): return 0 if stmt.modname == "__future__": return 1 else: return 0 class FutureParser: features = ("nested_scopes", "generators", "division", "absolute_import", "with_statement", "print_function", "unicode_literals") def __init__(self): self.found = {} # set def visitModule(self, node): stmt = node.node for s in stmt.nodes: if not self.check_stmt(s): break def check_stmt(self, stmt): if is_future(stmt): for name, asname in stmt.names: if name in self.features: self.found[name] = 1 else: raise SyntaxError, \ "future feature %s is not defined" % name stmt.valid_future = 1 return 1 return 0 def get_features(self): """Return list of features enabled by future statements""" return self.found.keys() class BadFutureParser: """Check for invalid future statements""" def visitFrom(self, node): if hasattr(node, 'valid_future'): return if node.modname != "__future__": return raise SyntaxError, "invalid future statement " + repr(node) def find_futures(node): p1 = FutureParser() p2 = BadFutureParser() walk(node, p1) walk(node, p2) return p1.get_features() if __name__ == "__main__": import sys from compiler import parseFile, walk for file in sys.argv[1:]: print file tree = parseFile(file) v = FutureParser() walk(tree, v) print v.found print