Clarify constructors

[nojaf]

Hello @cartermp,

I'm wondering what the style guide says about constructors and long ones in particular.

For example:

let thing = new Foobar(a, b)

let otherThing =
    new Foobar(
        longname1,
        longname2
    )

let m = new Meh(a)

let otherThing =
    new Foobar(
        longname1,
        longname2,
        longname3,
        longname4,
        longname5,
        longname6,
        longname7
    )

When to use multiple lines? Where to align in the indentation?

Fantomas today would format this as:

let thing = new Foobar(a, b)

let otherThing =
    new Foobar(longname1, longname2)

let m = new Meh(a)

let otherThing =
    new Foobar(longname1,
               longname2,
               longname3,
               longname4,
               longname5,
               longname6,
               longname7)

I'm asking this question in order to see if the Microsoft style guide will deviate from what the G-Research guide has in mind.

---

Document Details

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• ID: 8c09996f-24ac-cf39-ef43-d7909cbc2b89
• Version Independent ID: 1efdd523-8552-6421-e149-74f76826ef8f
• Content: F# code formatting guidelines
• Content Source: docs/fsharp/style-guide/formatting.md
• Product: dotnet-fsharp
• GitHub Login: @cartermp
• Microsoft Alias: phcart

[cartermp]

Hmm, I suppose this one feels the best to me:

let otherThing =
    new Foobar(
        longname1,
        longname2,
        longname3,
        longname4,
        longname5,
        longname6,
        longname7
    )

Happy to adjust it to be more along those lines. I've found that I'll do similar formatting in the F# codebase for some or our longer calls.

[cartermp]

Same goes for method calls / static members. Thoughts?

[nojaf]

Do you mean things like

let myValue =
    Regex.Match(
        "my longer input string with some interesting content in it",
        "myRegexPattern"
    )

let untypedRes = 
    checker.ParseFile(
        fileName, 
        sourceText,
        parsingOptionsWithDefines
    )

That could work.

[cartermp]

Yep!

[nojaf]

Great, this feels very consistent with the second sample of https://docs.microsoft.com/en-us/dotnet/fsharp/style-guide/formatting#formatting-discriminated-unions.

Would you accept a PR here?

[cartermp]

Yep!