Moduleghc-10.0.0.20260917GHC2024

GHC.Stg.Subst

Synopsis

data Subst
type IdSubstEnv
value emptySubst
value mkEmptySubst
value substBndr
value substBndrs
value lookupIdSubst
value noWarnLookupIdSubst
value extendInScope
value extendSubst

Packageghc-10.0.0.20260917
Exports10
LanguageGHC2024
LicenceBSD-3-Clause
SourceSubst.hs

datadata Subst

A renaming substitution from Ids to Ids. Like RnEnv2, but not maintaining pairs of substitutions. Like GHC.Core.Subst.Subst, but with the domain being Ids instead of entire CoreExpr.

Constructors

Subst InScopeSet IdSubstEnv

typetype IdSubstEnv = IdEnv Id

valueemptySubst :: Subst

Source#

emptySubst = mkEmptySubst emptyInScopeSet

valuemkEmptySubst :: InScopeSet -> Subst

Source#

Constructs a new Subst assuming the variables in the given InScopeSet are in scope.

valuesubstBndr :: Id -> Subst -> (Id, Subst)

Source#

Substitutes an Id for another one according to the Subst given in a way that avoids shadowing the InScopeSet, returning the result and an updated Subst that should be used by subsequent substitutions.

valuesubstBndrs :: Traversable f => f Id -> Subst -> (f Id, Subst)

Source#

substBndrs = runState . traverse (state . substBndr)

valuelookupIdSubst :: HasDebugCallStack => Id -> Subst -> Id

Source#

Substitutes an occurrence of an identifier for its counterpart recorded in the Subst.

valuenoWarnLookupIdSubst :: HasDebugCallStack => Id -> Subst -> Id

Source#

Substitutes an occurrence of an identifier for its counterpart recorded in the Subst. Does not generate a debug warning if the identifier to to substitute wasn't in scope.

valueextendInScope :: Id -> Subst -> Subst

Source#

Add the Id to the in-scope set and remove any existing substitutions for it.

valueextendSubst :: Id -> Id -> Subst -> Subst

Source#

Add a substitution for an Id to the Subst: you must ensure that the in-scope set is such that TyCoSubst Note [The substitution invariant] holds after extending the substitution like this.