ndmitchell/hlint

Incorrect redundant bracket warning with OverloadedRecordDot

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#1,458 opened on Feb 13, 2023

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buggood first issue

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Description

given

newtype T = T { f :: B }

g :: A -> T
a :: A

The code

(g a).f

uses the record dot operator. HLint recognizes this as the compose operator and incorrectly warns of a redundant bracket. Removing the bracket breaks the code, of course.

Contributor guide

Research direction
Find the rule that triggers the redundant bracket warning and modify it to exclude cases where the inner expression is a field selector (e.g., (g a).f). Ensure to handle the OverloadedRecordDot extension.
Tech stack
None
Domain
tooling
Issue type
Bug
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
3
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
Half day
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
Haskell
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
60