[FS-1030] - Anonymous records

[dsyme]

This adds anonymous records to the F# compiler per RFC FS-1030.

Please discuss on the RFC or below - if the discussion gets long we will move to the RFC discussion thread.

The implementation is not yet complete but I believe it to be stable and usable - there are just some corner cases to finish off and considerably more testing to add, specifically

Design:

• Resolve issues around field ordering (currently field ordering is significant)

Implementation:

• Equality, hash and comparison on {| X = 1; Y = 2 |} Kind B types
• ToString on {| X = 1; Y = 2 |} Kind B types
• sprintf "%A" on {| X = 1; Y = 2 |} Kind B types
• Quick info
• Auto complete
• Highlight symbols
• F# Interactive multiple fragments
• Field ordering
• Find all references
• Go-to-definition

Testing:

• Unit testing for language service features
• LINQ queries
• Test suitability of {| X = 1; Y = 2 |} types for working with known common libraries accepting C# anonymous types
• Add tests for negative case error messages

If anyone wants to give a hand with the testing that would be great. I think it's really important that someone else besides myself do serious testing on this feature. I'd love someone to try this out and give early feedback on usability and "fit and polish".

Note: F# Interactive currently doesn't work properly:

> {|  X = 1 |};;
val it : {|X : int|} = {X = 1;}

> {|  X = 1 |};;

error FS0193: internal error: Duplicate type name within an assembly.

[et1975]

I didn't see an example of decomposition, will this be possible?

let {| x = x |} = anonymousRecord

What would the Kind B syntax be like for this?
How could one distinguish between Kind A and Kind B types of same shape?

[dsyme]

@et1975 I'm not certain we need to allow decomposition for these (I'm not a big fan of pattern matching on records). But if we did, it would be

let {| x = x |} = anonymousRecordKindA

let (new {| x = x |}) = anonymousRecordKindB

[vasily-kirichenko]

It's fantastic. I didn't even know it's coming or even RFCed.

1. Proper tooltip on value as a whole

2. No completion:

3. No tooltip/find usages/etc. on fields neither on definition nor on usage site (I guess there's no FSharpSymbol?)

4. %A formatting is same as for tuples. Maybe it's better to adopt the one used for records?

let x = {| IntF = 1; StringF = "foo" |}
printfn "x = %A" x

> x = (1, "foo")

5. Structs!

[vasily-kirichenko]

About symbol absence, I think we just should notify the sink about fields, currently there is no ones:

[dsyme]

@yawaramin actually please ask that one on the RFC thread

[yawaramin]

@dsyme sorry, I deleted my question after I thought about it some more--I think I understand the difference, but I will repost on the RFC thread (i.e. fsharp/fslang-design#170 ) in case the discussion brings value.

[dsyme]

I've updated the PR to include code for equality, comparison, ToString and record-reflection

[dsyme]

Closed as targeted dev15.6 for some reason