lib-python.2.5.compiler.future.py Maven / Gradle / Ivy
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Jython is an implementation of the high-level, dynamic, object-oriented
language Python written in 100% Pure Java, and seamlessly integrated with
the Java platform. It thus allows you to run Python on any Java platform.
"""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")
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