| 123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104 |
- """
- Based on fix_next.py by Collin Winter.
- Replaces it.next() -> next(it), per PEP 3114.
- Unlike fix_next.py, this fixer doesn't replace the name of a next method with __next__,
- which would break Python 2 compatibility without further help from fixers in
- stage 2.
- """
- # Local imports
- from lib2to3.pgen2 import token
- from lib2to3.pygram import python_symbols as syms
- from lib2to3 import fixer_base
- from lib2to3.fixer_util import Name, Call, find_binding
- bind_warning = "Calls to builtin next() possibly shadowed by global binding"
- class FixNextCall(fixer_base.BaseFix):
- BM_compatible = True
- PATTERN = """
- power< base=any+ trailer< '.' attr='next' > trailer< '(' ')' > >
- |
- power< head=any+ trailer< '.' attr='next' > not trailer< '(' ')' > >
- |
- global=global_stmt< 'global' any* 'next' any* >
- """
- order = "pre" # Pre-order tree traversal
- def start_tree(self, tree, filename):
- super(FixNextCall, self).start_tree(tree, filename)
- n = find_binding('next', tree)
- if n:
- self.warning(n, bind_warning)
- self.shadowed_next = True
- else:
- self.shadowed_next = False
- def transform(self, node, results):
- assert results
- base = results.get("base")
- attr = results.get("attr")
- name = results.get("name")
- if base:
- if self.shadowed_next:
- # Omit this:
- # attr.replace(Name("__next__", prefix=attr.prefix))
- pass
- else:
- base = [n.clone() for n in base]
- base[0].prefix = ""
- node.replace(Call(Name("next", prefix=node.prefix), base))
- elif name:
- # Omit this:
- # n = Name("__next__", prefix=name.prefix)
- # name.replace(n)
- pass
- elif attr:
- # We don't do this transformation if we're assigning to "x.next".
- # Unfortunately, it doesn't seem possible to do this in PATTERN,
- # so it's being done here.
- if is_assign_target(node):
- head = results["head"]
- if "".join([str(n) for n in head]).strip() == '__builtin__':
- self.warning(node, bind_warning)
- return
- # Omit this:
- # attr.replace(Name("__next__"))
- elif "global" in results:
- self.warning(node, bind_warning)
- self.shadowed_next = True
- ### The following functions help test if node is part of an assignment
- ### target.
- def is_assign_target(node):
- assign = find_assign(node)
- if assign is None:
- return False
- for child in assign.children:
- if child.type == token.EQUAL:
- return False
- elif is_subtree(child, node):
- return True
- return False
- def find_assign(node):
- if node.type == syms.expr_stmt:
- return node
- if node.type == syms.simple_stmt or node.parent is None:
- return None
- return find_assign(node.parent)
- def is_subtree(root, node):
- if root == node:
- return True
- return any(is_subtree(c, node) for c in root.children)
|
