Skip to content

GitLab

  • Menu
Projects Groups Snippets
  • Help
    • Help
    • Support
    • Community forum
    • Submit feedback
  • Sign in / Register
  • GHC GHC
  • Project information
    • Project information
    • Activity
    • Labels
    • Members
  • Repository
    • Repository
    • Files
    • Commits
    • Branches
    • Tags
    • Contributors
    • Graph
    • Compare
    • Locked Files
  • Issues 4,869
    • Issues 4,869
    • List
    • Boards
    • Service Desk
    • Milestones
    • Iterations
  • Merge requests 456
    • Merge requests 456
  • CI/CD
    • CI/CD
    • Pipelines
    • Jobs
    • Schedules
    • Test Cases
  • Deployments
    • Deployments
    • Releases
  • Analytics
    • Analytics
    • Value stream
    • CI/CD
    • Code review
    • Insights
    • Issue
    • Repository
  • Wiki
    • Wiki
  • Snippets
    • Snippets
  • Activity
  • Graph
  • Create a new issue
  • Jobs
  • Commits
  • Issue Boards
Collapse sidebar
  • Glasgow Haskell Compiler
  • GHCGHC
  • Issues
  • #3219
Closed
Open
Created May 12, 2009 by dmwit@trac-dmwit

functions on records with overloaded names can be given a too-specific type

Here's a reduced test-case showing a discrepancy between the symmetric functions foo and bar; the inferred type for foo is too specific.

data T a = A{ m1 :: a } | B{ m1, m2 :: a } | C{ m2 :: a }

-- bar :: (t -> a) -> T t -> T a
bar f x@(A m) = x{m1 = f m}

-- foo :: (a -> a) -> T a -> T a
foo f x@(C m) = x{m2 = f m}
Trac metadata
Trac field Value
Version 6.10.1
Type Bug
TypeOfFailure OtherFailure
Priority normal
Resolution Unresolved
Component Compiler (Type checker)
Test case
Differential revisions
BlockedBy
Related
Blocking
CC
Operating system
Architecture
To upload designs, you'll need to enable LFS and have an admin enable hashed storage. More information
Assignee
Assign to
Time tracking