leanprover / leanprover/lean4

Syntax match does not put info on variables under repetitions

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enhancement P-low
Dominant language
Lean
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Merged PRs (30d)
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Description

syntax "repro" (ident)? ident : command
example : Lean.Syntax → Option Lean.Syntax
  | `(repro $[$x:ident]? a) => x
             --^ textDocument/hover
  | `(repro $[$x:ident]? b) => x
             --^ textDocument/hover
                             --^ textDocument/definition
  | _ => none

Only the x in the first match arm is highlighted like a variable. Furthermore, both x occurrences in the bodies jump to the x from the first match arm, which suggests that the binder for the second x is being misplaced on the syntax for the first one.

Contributor guide

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First steps

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  3. Fork the repository and make your change on a branch.
  4. Open a pull request that references the issue number.

Research direction

Run the provided Lean syntax-match reproduction and inspect the textDocument/hover and textDocument/definition results for both match arms. Done means each arm's x has variable information and each x in a match body resolves to its own arm's binder.

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
35/100

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