Latest fantomas breaks Falanx indentation

[7sharp9]

Description

The latest 2.9.1 has incorrect indentation

Repro code

See jet/falanx#84

[nojaf]

Hi @7sharp9, could you give us some more pointers how to solve this.
The F# code in jet/falanx#84 is coming from where?
Would it be possible to have a smaller reproduction in the online tool?

[jindraivanek]

I think main culprit here is let ... in ... support (

fantomas/src/Fantomas/CodePrinter.fs

Line 665 in c5597b7

atCurrentColumn (genLetOrUseList astContext bs +> ifElse isInSameLine (!- " in ") sepNln +> genExpr astContext e)

).

• It doesn't work correctly for multiline expr after in - it tries to output it like this

let x = 1 in ()
             x

which is not valid

• in shoudln't be used at all when generating from AST (I guess it is used because all nodes have same zero range).

I will try to fix it by disabling let ... in for multiline and when generating from AST.