Allow containers to wrap gracefully

And do not force breaks on commas in the middle of for comprehensions

yapf/yapflib/format_decision_state.py

@@ -203,7 +203,9 @@ def MustSplit(self):
  # Allow the fallthrough code to handle the closing bracket.
  if current != opening.matching_bracket:
  # If the container doesn't fit in the current line, must split
- return not self._ContainerFitsOnStartLine(opening)
+ if (subtypes.COMP_FOR not in current.subtypes and
+ not self._ContainerFitsOnStartLine(opening)):
+ return True
 
  if (self.stack[-1].split_before_closing_bracket and
  (current.value in '}]' and style.Get('SPLIT_BEFORE_CLOSING_BRACKET') or
@@ -546,9 +548,14 @@ def SurroundedByParens(token):
  return True
  else:
  # Split after the opening of a container if it doesn't fit on the
- # current line.
+ # current line, including checking for wrapping.
  if not self._FitsOnLine(previous, previous.matching_bracket):
- return True
+ arg_lengths = _CalculateArgLengths(previous)
+ start_col = self.column + len(current.value) + len(previous.value)
+ for length in arg_lengths:
+ length += start_col
+ if length > self.column_limit:
+ return True
 
  ###########################################################################
  # Original Formatting Splitting
@@ -1106,10 +1113,8 @@ def _ContainerFitsOnStartLine(self, opening):
  self.stack[-1].indent) <= self.column_limit
 
 
-_COMPOUND_STMTS = frozenset({
- 'for', 'while', 'if', 'elif', 'with', 'except', 'def', 'class', 'match',
- 'case'
-})
+_COMPOUND_STMTS = frozenset({'for', 'while', 'if', 'elif', 'with', 'except',
+ 'def', 'class', 'match', 'case'})
 
 
 def _IsCompoundStatement(token):