-
9831385b
by Vladislav Zavialov at 2026-03-27T17:22:30-04:00
Infix holes in types (#11107)
This patch introduces several improvements that follow naturally from
refactoring HsOpTy to represent the operator as an HsType, aligning it
with the approach taken by OpApp and HsExpr.
User-facing changes:
1. Infix holes (t1 `_` t2) are now permitted in types, following the
precedent set by term-level expressions.
Test case: T11107
2. Error messages for illegal promotion ticks are now reported at more
precise source locations.
Test case: T17865
Internal changes:
* The definition of HsOpTy now mirrors that of OpApp:
| HsOpTy (XOpTy p) (LHsType p) (LHsType p) (LHsType p)
| OpApp (XOpApp p) (LHsExpr p) (LHsExpr p) (LHsExpr p)
This moves us one step closer to unifying HsType and HsExpr.
* Ignoring locations,
the old pattern match (HsOpTy x prom lhs op rhs)
is now written as (HsOpTy x lhs (HsTyVar x' prom op) rhs)
but we also handle (HsOpTy x lhs (HsWildCardTy x') rhs)
Constructors other than HsTyVar and HsWildCardTy never appear
in the operator position.
* The various definitions across the compiler have been updated to work
with the new representation, drawing inspiration from the term-level
pipeline where appropriate. For example,
ppr_infix_ty <=> ppr_infix_expr
get_tyop <=> get_op
lookupTypeFixityRn <=> lookupExprFixityRn
(the latter is factored out from rnExpr)
Test cases: T11107 T17865
-
5b6757d7
by mangoiv at 2026-03-27T17:23:19-04:00
ci: build i386 non-validate for deb12
This is a small fix that will unlock ghcup metadata to run, i386 debian
12 was missing as a job.
-
196cc1fa
by Simon Peyton Jones at 2026-03-30T12:45:45+01:00
Add Invariant (NoTypeShadowing) to Core
This commit addresses #26868, by adding
a new invariant (NoTypeShadowing) to Core.
See Note [No type-shadowing in Core] in GHC.Core
-
56ab30db
by Simon Peyton Jones at 2026-03-30T12:51:31+01:00
Major refactor of free-variable functions
For some time we have had two free-variable mechanims for types:
* The "FV" mechanism, embodied in GHC.Utils.FV, which worked OK, but
was fragile where eta-expansion was concerned.
* The TyCoFolder mechanism, using a one-shot EndoOS accumulator
I finally got tired of this and refactored the whole thing, thereby
addressing #27080. Now we have
* `GHC.Types.Var.FV`, which has a composable free-variable result type,
very much in the spirit of the old `FV`, but much more robust.
(It uses the "one shot trick".)
* GHC.Core.TyCo.FVs now has just one technology for free variables.
All this led to a lot of renaming.
There are couple of error-message changes. The change in T18451
makes an already-poor error message even more mysterious. But
it really needs a separate look.