Skip to content
Snippets Groups Projects
Commit 911e0c4e authored by Simon Peyton Jones's avatar Simon Peyton Jones
Browse files

Care with occCheckExpand in kind of occurrences 

Issue #18451 showed that we could get an infinite type, through
over-use of occCheckExpand in the kind of an /occurrence/ of a
type variable.

See Note [Occurrence checking: look inside kinds] in GHC.Core.Type

This patch fixes the problem by making occCheckExpand less eager
to expand synonyms in kinds.

It also improves pretty printing of kinds, by *not* suppressing
the kind on a tyvar-binder like
    (a :: Const Type b)
where type Const p q = p.  Even though the kind of 'a' is Type,
we don't want to suppress the kind ascription.  Example: the
error message for polykinds/T18451{a,b}. See GHC.Core.TyCo.Ppr
Note [Suppressing * kinds].
parent c0979cc5
No related branches found
No related tags found
No related merge requests found
Pipeline #22404 canceled
Stage: lint
    Stage: quick-build
      Stage: build
        Stage: full-build
          Stage: cleanup
            Stage: packaging
              Stage: testing
                Hide whitespace changes
                Inline Side-by-side
                Showing
                with 169 additions and 40 deletions
                0% or .
                You are about to add 0 people to the discussion. Proceed with caution.
                Finish editing this message first!
                Please register or to comment