racket / racket/typed-racket

Function types with 2+ arguments and simple proposition fail to parse

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Dominant language
Racket
Stars
575
Forks
106
Avg merge
2h 1m
Merged PRs (30d)
2

Description

What version of Racket are you using?

6.8.0.1

What program did you run?
#lang typed/racket
(define-type T1 (→ Any Number Boolean : String))                    ;; Fails
(define-type T2 (→ Any Number Boolean : #:+ String #:- (! String))) ;; Works
What should have happened?

The first syntax should be accepted

My actual use case is for the following type:

(∀ (A D) (→ Any
            (→ Any Boolean : A)
            (→ Any Boolean : D)
            Boolean : (Pairof A D)))
If you got an error message, please include it here.
→: expected the identifier `:' or expected one of these literals: #:+, #:-, or #:object
  parsing context: 
   while parsing different things... in: String

Contributor guide

No contributing guide indexed for this repository

First steps

  1. Read the whole issue, then the project's contributing guide.
  2. Comment on the issue to say you are picking it up — it saves two people doing the same work.
  3. Fork the repository and make your change on a branch.
  4. Open a pull request that references the issue number.

Research direction

Reproduce the failure in Racket 6.8.0.1 with the T1 and T2 type definitions, then inspect the parser for → function types with multiple arguments and a simple proposition. Done means the T1 syntax and the shown quantified type are accepted without the reported parsing error, with regression coverage for the failing form.

Written by the indexing model from the issue text.

Assessment

Domain
compilers
Issue type
Bug
Difficulty
4/5
Estimated time
3-5 days
Activity status
Stale
Clarity
Mostly clear
Newbie friendliness
42/100

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