def close_scope(self,
node,
prefix_attr='prefix',
suffix_attr='suffix',
trailing_comma=False,
single_paren=False):
"""Close a parenthesized scope on the given node, if one is open."""
# Ensures the prefix + suffix are not None
if fmt.get(node, prefix_attr) is None:
fmt.set(node, prefix_attr, '')
if fmt.get(node, suffix_attr) is None:
fmt.set(node, suffix_attr, '')
if not self._parens or node not in self._scope_stack[-1]:
return
symbols = {')'}
if trailing_comma:
symbols.add(',')
parsed_to_i = self._i
parsed_to_loc = prev_loc = self._loc
encountered_paren = False
result = ''
for tok in self.takewhile(
lambda t: t.type in FORMATTING_TOKENS or t.src in symbols):
# Consume all space up to this token
result += self._space_between(prev_loc, tok)
if tok.src == ')' and single_paren and encountered_paren:
self.rewind()
parsed_to_i = self._i
parsed_to_loc = tok.start
fmt.append(node, suffix_attr, result)
break
# Consume the token itself
result += tok.src
if tok.src == ')':
# Close out the open scope
encountered_paren = True
self._scope_stack.pop()
fmt.prepend(node, prefix_attr, self._parens.pop())
fmt.append(node, suffix_attr, result)
result = ''
parsed_to_i = self._i
parsed_to_loc = tok.end
if not self._parens or node not in self._scope_stack[-1]:
break
prev_loc = tok.end
# Reset back to the last place where we parsed anything
self._i = parsed_to_i
self._loc = parsed_to_loc
def optional_token(self, node, attr_name, token_val,
allow_whitespace_prefix=False, default=False):
"""Try to parse a token and attach it to the node."""
del default
fmt.append(node, attr_name, '')
token = (self.tokens.peek_non_whitespace()
if allow_whitespace_prefix else self.tokens.peek())
if token and token.src == token_val:
parsed = ''
if allow_whitespace_prefix:
parsed += self.ws()
fmt.append(node, attr_name,
parsed + self.tokens.next().src + self.ws())
