Allow typed bindings(and!) in CE without parentheses #18682
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edgarfgp
changed the title
and! typed bindings…sharp into allow-and-bang-typed-bindings
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@edgarfgp Thanks for this! Could you also cover error cases in the grammar, please? If unified with the let parsing, we could probably get a lot of recovery for free as well.
| @@ -4107,6 +4107,22 @@ moreBinders: | |||
| let trivia = { AndBangKeyword = rhs parseState 1; EqualsRange = mEquals; InKeyword = Some mIn } | |||
| SynExprAndBang(spBind, $1, true, $2, $4, m, trivia) :: $6 } | |||
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| | AND_BANG headBindingPattern opt_topReturnTypeWithTypeConstraints EQUALS typedSequentialExprBlock IN moreBinders %prec expr_let | |||
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At this point we should probably try to unify let and let! parsing rules and check whether it's a ! version or not in the type checker. As the first step it should be at least parse it in a unified manner and then create different tree nodes conditionally. But ideally it should be something like isComputed: bool flag that the type checker would inspect.
@edgarfgp Do you think it's feasible to unify the rules as part of this PR?
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Do you think it's feasible to unify the rules as part of this PR?
Agreed. I think as part of this PR I can try and I can try and unify the parsing rules for let, let! and and!.
Could you also cover error cases in the grammar, please?
Yeah I can add syntax tree test that show the parsing errors.
cc @T-Gro any objections ?
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Description
Allow computation expression (CE) bindings (
let!,use!,and!) to accept type annotations without requiring parentheses.Continuation of #18508
Implements RFC FS-1329: fsharp/fslang-design#802
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