Formatter: With / AsyncWith (includes WithItem)

[MichaReiser]

• With format StmtWith #5350
• AsyncWith
• Parentheses in WithItem

[MichaReiser]

With has been implemented by #5350

@davidszotten do you want to look into/plan to work on generalizing the logic by either defining an union enum or a trait for AsyncWith?

[davidszotten]

sure, will take a look

[MichaReiser]

I'm not sure how to handle this inside of the formatter but we're currently adding to many parentheses for

# Input
with (aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa + bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb) as c:
    ...

# Ruff Output
with (
	(
		aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa + bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb
	) as c,
):
	...

# Black
with (
    aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa + bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb
) as c:
    ...

Because both the binary expression and the with statement are adding parentheses. It may be necessary to explicitly enumerate all the expressions that support breaking the left side, similar to can_break_expr OR rethink how we group elements, potentially use best_fitting.

Other interesting patterns

with (aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa + bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb) as c, (aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa + bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb) as c:
    ...

with (aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa + bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb), (aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa + bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb):
    ...

with aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa + bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb as c, aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa + bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb as c:
    ...

We don't need to match black precisely but I do prefer black's formatting overall.

We can tackle this in a separate PR and I can also look into it

[davidszotten]

i was trying to follow the code to understand how if_group_breaks works (but failed). does the outer group also consider itself broken if the inner one does? or what is causing the outer group to expand?

[MichaReiser]

i was trying to follow the code to understand how if_group_breaks works (but failed). does the outer group also consider itself broken if the inner one does? or what is causing the outer group to expand?

That's correct. An outer group always expands if an inner group expands. I'm on my phone but there's a propagate_expands that implements this behavior.

A sequence of groups expands the groups from right to left

Best fitting allows you to provide multiple versions of the same content and the printer tries to pick the first one that fits (or falls back to an expanded version)

If group breaks accepts an optional with_group. It makes the content dependent on whatever the group with that given id expands rather than the enclosing group. However, the referred group must either be a parent or precede the content.

I think that summarizes most grouping IR elements.

In this case, it may be necessary that we enumerate all expressions for which we don't want parantheses.

[davidszotten]

ok. might leave this for you (separate pr seems ok)