[SR-6116] [SourceKit] Introduce "source.lang.swift.expr.closure" in structure

[marcelofabri]

Previous ID	SR-6116
Radar	None
Original Reporter	@marcelofabri
Type	New Feature
Status	Resolved
Resolution	Done

Additional Detail from JIRA

Votes	0
Component/s	Source Tooling
Labels	New Feature
Assignee	@marcelofabri
Priority	Medium

md5: 328c664880b57a88af33aa16267d132f

Issue Description:

It'd be useful for tools like SwiftLint to get information about closure expressions in source code.

Several rules currently need this information and obtain it using heuristics. It'd be way more reliable if this was available via SourceKit.

Some rules that could use it:

• Closure End Indentation

• Closure Parameter Position

• Closure Spacing

• Empty Parentheses with Trailing Closure

• Implicit Return

• Multiple Closures with Trailing Closure

• Trailing Closure

• Unneeded Parentheses in Closure Argument

• Unused Closure Parameter

• Vertical Parameter Alignment On Call

It'd be also useful to know whether a closure is a trailing closure inside a function call, but I'm not sure if it's semantically correct to add this information on this structure, because it's something available in several declarations such as CallExpr and SubscriptExpr, not ClosureExpr.

[marcelofabri]

#13617