Clarify constructors

[Smaug123]

Sadly our "preferred" formatting is a syntax error due to offside indentation. That would be:

let thing = new Foobar(
    thing1,
    thing2
)

I've bitten the bullet and introduced another newline.

Aside: we are rather unclear on whether we want a space after the word Foobar here. I think sometimes it's a syntax error to insert a space.

[nojaf]

At first glance, the other newline would be more consistent with anything I've seen so far.
To clarify I don't think there is any multiline construct that does still start right after the =.
For example:

let person = {
    Name = "barry"
}

So from an implementation point of view, I welcome the extra newline.

Does the example look the same when it is in an inner let binding?

let myFunction () =
    let thing =
        new FooBar (
             thing1,
             thing2
        )

    ()

[Smaug123]

I think that looks right, except that I'm starting to think maybe it should be new FooBar( without the additional space before the bracket. I don't think we have enough of this kind of code for my opinions to be strong here; I'll ask the team.

[Smaug123]

Looks like the rest of the team agrees that your suggestion is correct except for the space after the constructor (since I'm quite sure I remember there being times where new required there to be no space).

[nojaf]

Is it by the way always a multiline construct or does that depend on the arguments of the constructor?

let thing = new Foobar(a, b)

let otherThing =
    new Foobar(
         thing1,
         thing2
    )

let m = new Meh(a) // what with only one argument?

[Smaug123]

If the arguments fit on one line, we put them on one line:

let thing = new Foobar(a, b)
let otherThing =
    new Foobar(
        longname1,
        longname2
    )
let m = new Meh(a)

[nojaf]

What if there is only one long argument?
Something like:

let myItem = new Foobar(someInitialStateThatHasQuietTheLongNameAndSeemsToGoOnAndOnAndOn)

Would it be

let myItem = 
    new Foobar(someInitialStateThatHasQuietTheLongNameAndSeemsToGoOnAndOnAndOn)

or

let myItem = 
    new Foobar(
        someInitialStateThatHasQuietTheLongNameAndSeemsToGoOnAndOnAndOn
    )

[Smaug123]

I think we have no strong preference here; I'll pick arbitrarily.

let myItem = new Foobar(someInitialStateThatHasQuietTheLongNameAndSeemsToGoOnAndOnAndOn)

[knocte]

I'll pick arbitrarily.

But that choice makes it more likely to surpass the possible horizontal limit of the dev to avoid horizontal scrolling.

[Smaug123]

This is predicated on the assumption that we can't fit it all on one line.

[nojaf]

Slightly related does this rule also apply for member calls, static members?
Things like:

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

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

[Smaug123]

I'd say it applies for those as well, yes.

[nojaf]

@Smaug123 dotnet/docs#21578 got merged, perhaps the same text can be added here as well.
See https://docs.microsoft.com/en-us/dotnet/fsharp/style-guide/formatting#formatting-constructors-static-members-and-member-invocations