F# values display badly in default formatting, esp plaintext

Therer are lots of cases where default formatting for F# values is way off. I’ll document a few here and try and make progress on this.

1. Evaluate a method info, e…d

   match <@ display("") @> with Quotations.Patterns.Call(_,mi,_) -> mi
   

   Expect: something reasonable Actual: a big mess

2. Evaluate “<@ 1 @>” in a notebook.

   Expect: Some reasonable of the quotation.
   Actual, a big mess, see image at bottom

   Best would really be just the ToString() I think:

   Value (1)
   

   For reference FSI shows this, which is not great but not awful.

       val it : Quotations.Expr<int> =
     Value (1)
    {CustomAttributes = [NewTuple (Value ("DebugRange"),
          NewTuple (Value ("stdin"), Value (1), Value (3), Value (1), Value (4)))];
     Raw = ...;
     Type = System.Int32;}
   

Quotation image:

[dsyme]

FWIW I think the best approach here in the short term would be “revert to printing plain text of F# values unless we are sure the result is going to look nice”

And use https://github.com/dotnet/interactive/issues/646 to control printing in plain text.

Exactly what this means in detail I’m not sure

[jonsequitur]

My current thinking is that we can allow this decision to be different per subkernel by adding support for subkernels specifying their own formatting rules, so for example the FSharpKernel could prefer FSI-style printing. C# doesn’t have a comparable mechanism and perhaps because of that, the feedback has been that the tabular output is more useful than ToString for most types.

In the short term this should make the F# experience better and more familiar while decoupling from the timeline for finding a better set of defaults for C#.