GHC.Core.FVs

A module concerned with finding the free variables of an expression.

Free variables of expressions and binding groups

exprFreeVars :: CoreExpr -> VarSet

Find all locally-defined free Ids or type variables in an expression returning a non-deterministic set.

exprsFreeVars :: [CoreExpr] -> VarSet

Find all locally-defined free Ids or type variables in several expressions returning a non-deterministic set.

exprFreeVarsDSet :: CoreExpr -> DVarSet

Find all locally-defined free Ids or type variables in an expression returning a deterministic set.

exprFreeVarsList :: CoreExpr -> [Var]

Find all locally-defined free Ids or type variables in an expression returning a deterministically ordered list.

exprsFreeVarsList :: [CoreExpr] -> [Var]

Find all locally-defined free Ids or type variables in several expressions returning a deterministically ordered list.

exprFreeIds :: CoreExpr -> IdSet

Find all locally-defined free Ids in an expression

exprsFreeIds :: [CoreExpr] -> IdSet

exprFreeIdsDSet :: CoreExpr -> DIdSet

Find all locally-defined free Ids in an expression returning a deterministic set.

exprsFreeIdsDSet :: [CoreExpr] -> DIdSet

Find all locally-defined free Ids in several expressions returning a deterministic set.

exprFreeIdsList :: CoreExpr -> [Id]

Find all locally-defined free Ids in an expression returning a deterministically ordered list.

exprsFreeIdsList :: [CoreExpr] -> [Id]

Find all locally-defined free Ids in several expressions returning a deterministically ordered list.

bindFreeVars :: CoreBind -> VarSet

Find all locally defined free Ids in a binding group

Selective free variables of expressions

type InterestingVarFun = Var -> Bool

Predicate on possible free variables: returns True iff the variable is interesting

exprSomeFreeVars

Arguments

:: InterestingVarFun

Says which Exprs are interesting

-> CoreExpr

-> VarSet

Finds free variables in an expression selected by a predicate

exprsSomeFreeVars :: InterestingVarFun -> [CoreExpr] -> VarSet

Finds free variables in several expressions selected by a predicate

exprSomeFreeVarsList

Arguments

:: InterestingVarFun

Says which Exprs are interesting

-> CoreExpr

-> [Var]

Finds free variables in an expression selected by a predicate returning a deterministically ordered list.

exprsSomeFreeVarsList :: InterestingVarFun -> [CoreExpr] -> [Var]

Finds free variables in several expressions selected by a predicate returning a deterministically ordered list.

Free variables of Rules, Vars and Ids

varTypeTyCoVars :: Var -> TyCoVarSet

varTypeTyCoFVs :: Var -> FV

idUnfoldingVars :: Id -> VarSet

idFreeVars :: Id -> VarSet

dIdFreeVars :: Id -> DVarSet

bndrRuleAndUnfoldingVarsDSet :: Id -> DVarSet

bndrRuleAndUnfoldingIds :: Id -> IdSet

idFVs :: Id -> FV

idRuleVars :: Id -> VarSet

stableUnfoldingVars :: Unfolding -> Maybe VarSet

ruleFreeVars :: CoreRule -> VarSet

Those variables free in the both the left right hand sides of a rule returned as a non-deterministic set

rulesFreeVars :: [CoreRule] -> VarSet

Those variables free in both the left right hand sides of several rules

rulesFreeVarsDSet :: [CoreRule] -> DVarSet

Those variables free in the both the left right hand sides of rules returned as a deterministic set

mkRuleInfo :: [CoreRule] -> RuleInfo

Make a RuleInfo containing a number of CoreRules, suitable for putting into an IdInfo

ruleLhsFreeIds :: CoreRule -> VarSet

This finds all locally-defined free Ids on the left hand side of a rule and returns them as a non-deterministic set

ruleLhsFreeIdsList :: CoreRule -> [Var]

This finds all locally-defined free Ids on the left hand side of a rule and returns them as a deterministically ordered list

ruleRhsFreeVars :: CoreRule -> VarSet

Those variables free in the right hand side of a rule returned as a non-deterministic set

rulesRhsFreeIds :: [CoreRule] -> VarSet

Those locally-defined free Ids in the right hand side of several rules returned as a non-deterministic set

exprFVs :: CoreExpr -> FV

Find all locally-defined free Ids or type variables in an expression returning a composable FV computation. See Note [FV naming conventions] in GHC.Utils.FV for why export it.

Orphan names

orphNamesOfType :: Type -> NameSet

orphNamesOfTypes :: [Type] -> NameSet

orphNamesOfCo :: Coercion -> NameSet

orphNamesOfCoCon :: CoAxiom br -> NameSet

orphNamesOfAxiomLHS :: CoAxiom br -> NameSet

orphNamesOfAxiomLHS collects the names of the concrete types and type constructors that make up the LHS of a type family instance, including the family name itself.

For instance, given `type family Foo a b`: `type instance Foo (F (G (H a))) b = ...` would yield [Foo,F,G,H]

Used (via orphNamesOfFamInst) in the implementation of ":info" in GHCi. and when determining orphan-hood for a FamInst or module

exprsOrphNames :: [CoreExpr] -> NameSet

Finds the free external names of several expressions: see exprOrphNames for details

Core syntax tree annotation with free variables

type FVAnn = DVarSet

type CoreExprWithFVs = AnnExpr Id FVAnn

Every node in an expression annotated with its (non-global) free variables, both Ids and TyVars, and type. NB: see Note [The FVAnn invariant]

type CoreExprWithFVs' = AnnExpr' Id FVAnn

type CoreBindWithFVs = AnnBind Id FVAnn

Every node in a binding group annotated with its (non-global) free variables, both Ids and TyVars, and type.

type CoreAltWithFVs = AnnAlt Id FVAnn

Every node in an expression annotated with its (non-global) free variables, both Ids and TyVars, and type.

freeVars :: CoreExpr -> CoreExprWithFVs

Annotate a CoreExpr with its (non-global) free type and value variables at every tree node.

freeVarsBind :: CoreBind -> DVarSet -> (CoreBindWithFVs, DVarSet)

freeVarsOf :: CoreExprWithFVs -> DIdSet

Inverse function to freeVars

freeVarsOfAnn :: FVAnn -> DIdSet

Extract the vars reported in a FVAnn