Question: How to achieve a particular function argument wrapping style

[gavingt]

I'm wondering if I can set a rule such that function calls get formatted like this:

let output = myMethod(a: p0, b: p1, 
  c: p2, d: p3, e: p4, f: p5, g: p6,
  h: p7, i: p8, j: p9)

Note how the second and third lines are indented one level (rather than the more common Swift style of indenting them to the first argument).

[calda]

I don't believe this is currently supported. The closest for that indentation is --wrap-arguments before-first, but that would wrap the a: param onto the following line.

[gavingt]

@calda Thanks for the reply! How difficult would it be for me to make a custom rule to accomplish this?

[calda]

It would be an additional option in the indent rule. Could be something like --after-first-indent single-level with the current default being --after-first-indent aligned.

+@nicklockwood for thoughts

In terms of difficulty, the indent rule is pretty complicated, but this change may not be too bad.

This is the relevant line of code in the indent rule:

SwiftFormat/Sources/Rules/Indent.swift

Line 189 in fe49575

indent = formatter.spaceEquivalentToTokens(from: start, upTo: nextIndex)

That creates the variable-width indentation. If you hard-code it to a single-level indentation with " ", you get the behavior you're looking for in that specific sample code. It would just have to be tweaked to use the correct indentation level based on the surrounding scope.