Member with indexer that has a getter and setter doesn't use and correctly

[baronfel]

Issue created from fantomas-online

Code

type TaskDefinition =
    abstract Item: name: string -> obj option with get, set

{ new TaskDefinition with
    member this.Item
        with get (name: string): obj option = None

    member this.Item
        with set (name: string) (v: obj option): unit =
            () }

Result

type TaskDefinition =
    abstract Item: name: string -> obj option with get, set

{ new TaskDefinition with
    member this.Item
        with set (name: string) (v: obj option): unit = ()
        with get (name: string): obj option = None }

Problem description

The problem here is that the with on the second property member (either getter or setter) needs to be an and if both getter and setter are provided.

type TaskDefinition =
    abstract Item: name: string -> obj option with get, set

{ new TaskDefinition with
    member this.Item
        with set (name: string) (v: obj option): unit = ()
        and get (name: string): obj option = None }

Note that if the source code isn't written in the separate-property-member syntax (see below) the format works.

{ new TaskDefinition with
    member this.Item
        with get (name: string): obj option = data.TryGet name

        and set (name: string) (v: obj option): unit =
            match v with
            | None -> data.Remove(name) |> ignore
            | Some v -> data.[name] <- v

    override this.``type``: string = "fakerun" }

Extra information

• The formatted result breaks by code.
• The formatted result gives compiler warnings.
• I or my company would be willing to help fix this.

Options

Fantomas master branch at 2022-03-05T20:07:44Z - d7fb5cb

Default Fantomas configuration

_{Did you know that you can ignore files when formatting from fantomas-tool or the FAKE targets by using a .fantomasignore file?}

[nojaf]

Hi, this rings a bell. SynPat.LongIdent can have an propertyKeyword which tells you if get or set was used.

We combine both members into:

fantomas/src/Fantomas/SourceTransformer.fs

Lines 119 to 125 in d7fb5cb

	let (|PropertyWithGetSetMemberDefn|_|) =
	function
	| MDMember x1 :: MDMember x2 :: xs ->
	match [ x1; x2 ] with
	| PropertyWithGetSet ((x1, x2), []) -> Some((x1, x2), xs)
	| _ -> None
	| _ -> None

and then we probably don't do the right thing in

fantomas/src/Fantomas/CodePrinter.fs

Lines 700 to 733 in d7fb5cb

	and genPropertyWithGetSet astContext (b1, b2) =
	match b1, b2 with
	| PropertyBinding (ats, px, ao, isInline, mf1, PatLongIdent (ao1, s1, pk1, ps1, _), eqR1, e1, _),
	PropertyBinding (_, _, _, _, _, PatLongIdent (ao2, _, pk2, ps2, _), eqR2, e2, _) ->
	let prefix =
	genPreXmlDoc px
	+> genAttributes astContext ats
	+> genMemberFlags mf1
	+> ifElse isInline (!- "inline ") sepNone
	+> opt sepSpace ao genAccess
	assert (ps1 |> Seq.map fst |> Seq.forall Option.isNone)
	assert (ps2 |> Seq.map fst |> Seq.forall Option.isNone)
	let ps1 = List.map snd ps1
	let ps2 = List.map snd ps2
	let genGet =
	genProperty astContext (genPropertyKeyword pk1) ao1 "get " ps1 SynBinding_Equals eqR1 e1
	let genSet =
	genProperty astContext (genPropertyKeyword pk2) ao2 "set " ps2 SynBinding_Equals eqR2 e2
	let genGetSet =
	match pk2 with
	| Some (PropertyKeyword.With _) -> genSet +> sepNln +> genGet
	| _ -> genGet +> sepNln +> genSet
	prefix
	+> !-s1
	+> indent
	+> sepNln
	+> genGetSet
	+> unindent
	| _ -> sepNone

anymore.

Are you interested in submitting a PR for this one?

[baronfel]

Of course! I'll probably take a look this weekend.