ghc-8.6.4: The GHC API

VarSet

Synopsis

# Var, Id and TyVar set types

A non-deterministic Variable Set

A non-deterministic set of variables. See Note [Deterministic UniqFM] in UniqDFM for explanation why it's not deterministic and why it matters. Use DVarSet if the set eventually gets converted into a list or folded over in a way where the order changes the generated code, for example when abstracting variables.

Identifier Set

Type Variable Set

Coercion Variable Set

Type or Coercion Variable Set

## Manipulating these sets

mapUnionVarSet :: (a -> VarSet) -> [a] -> VarSet Source #

map the function over the list, and union the results

mapVarSet :: Uniquable b => (a -> b) -> UniqSet a -> UniqSet b Source #

Determines the pluralisation suffix appropriate for the length of a set in the same way that plural from Outputable does for lists.

Arguments

 :: VarSet The things to be pretty printed -> ([Var] -> SDoc) The pretty printing function to use on the elements -> SDoc SDoc where the things have been pretty printed

Pretty-print a non-deterministic set. The order of variables is non-deterministic and for pretty-printing that shouldn't be a problem. Having this function helps contain the non-determinism created with nonDetEltsUFM. Passing a list to the pretty-printing function allows the caller to decide on the order of Vars (eg. toposort them) without them having to use nonDetEltsUFM at the call site. This prevents from let-binding non-deterministically ordered lists and reusing them where determinism matters.

# Deterministic Var set types

Deterministic Variable Set

Deterministic Identifier Set

Deterministic Type Variable Set

Deterministic Type or Coercion Variable Set

## Manipulating these sets

Add a list of variables to DVarSet

mapUnionDVarSet :: (a -> DVarSet) -> [a] -> DVarSet Source #

Map the function over the list, and union the results

True if non-empty intersection

True if empty intersection

delDVarSetList :: DVarSet -> [Var] -> DVarSet Source #

Delete a list of variables from DVarSet

foldDVarSet :: (Var -> a -> a) -> a -> DVarSet -> a Source #

transCloVarSet for DVarSet

partitionDVarSet :: (Var -> Bool) -> DVarSet -> (DVarSet, DVarSet) Source #

Partition DVarSet according to the predicate given

Convert a DVarSet to a VarSet by forgeting the order of insertion