JuliaLang/julia

"@inferred requires a call expression" for do notation

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#59,114 opened on Jul 28, 2025

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good first issue

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Description

Lambda functions work fine, while the same do-block throws an error:

julia> using Test

julia> @inferred map(x->x, [1,2])
2-element Vector{Int64}:
 1
 2

julia> @inferred map([1,2]) do x
       x
       end
ERROR: LoadError: @inferred requires a call expression

Contributor guide

Research direction
Inspect the @inferred macro implementation to understand why it rejects do block expressions, and modify it to accept them by handling the expanded call expression.
Tech stack
None
Domain
backend
Issue type
Bug
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
2
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
1-3 hours
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
Active
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
Clear
Prerequisites
Julia
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
75