HERMIT.Context

HERMIT Contexts

Path Synonyms

type AbsolutePathH = AbsolutePath Crumb

type LocalPathH = LocalPath Crumb

The Standard Context

data HermitC

The HERMIT context, containing all bindings in scope and the current location in the AST. The bindings here are lazy by choice, so that we can avoid the cost of building the context if we never use it.

Instances

HasGlobalRdrEnv HermitC

HasCoreRules HermitC

ReadBindings HermitC

BoundVars HermitC

AddBindings HermitC

ExtendPath HermitC Crumb

Extend the AbsolutePath stored in the HERMIT context.

ReadPath HermitC Crumb

Retrieve the AbsolutePath to the current node, from the HERMIT context.

Extern [RewriteH Core]

Extern (BiRewriteH Core)

Extern (RewriteH CoreTC)

Extern (RewriteH Core)

Extern (TranslateH CoreTC String)

Extern (TranslateH CoreTC ())

Extern (TranslateH CoreTC LocalPathH)

Extern (TranslateH Core String)

Extern (TranslateH Core ())

Extern (TranslateH Core LocalPathH)

initHermitC :: ModGuts -> HermitC

Create the initial HERMIT HermitC by providing a ModGuts.

Bindings

data HermitBindingSite

HERMIT's representation of variable bindings. Bound expressions cannot be inlined without checking for shadowing issues (using the depth information).

Constructors

LAM

A lambda-bound variable.

NONREC CoreExpr

A non-recursive binding of an expression.

REC CoreExpr

A recursive binding that does not depend on the current expression (i.e. we're not in the binding group of that binding).

SELFREC

A recursive binding of a superexpression of the current node (i.e. we're in the RHS of that binding).

MUTUALREC CoreExpr

A recursive binding that is mutually recursive with the binding under consideration (i.e. we're in another definition in the same recursive binding group.).

CASEALT

A variable bound in a case alternative.

CASEWILD CoreExpr (AltCon, [Var])

A case wildcard binder. We store both the scrutinised expression, and the case alternative AltCon and variables.

FORALL

A universally quantified type variable.

type BindingDepth = Int

The depth of a binding. Used, for example, to detect shadowing when inlining.

data HermitBinding

hbDepth :: HermitBinding -> BindingDepth

hbSite :: HermitBinding -> HermitBindingSite

hbPath :: HermitBinding -> AbsolutePathH

hermitBindingSiteExpr :: HermitBindingSite -> KureM CoreExpr

Retrieve the expression in a HermitBindingSite, if there is one.

hermitBindingSummary :: HermitBinding -> String

hermitBindingExpr :: HermitBinding -> KureM CoreExpr

Retrieve the expression in a HermitBinding, if there is one.

Adding bindings to contexts

class AddBindings c where

A class of contexts that can have HERMIT bindings added to them.

Methods

addHermitBindings :: [(Var, HermitBindingSite, AbsolutePathH)] -> c -> c

Add a complete set of parrallel bindings to the context. (Parallel bindings occur in recursive let bindings and case alternatives.) This can also be used for solitary bindings (e.g. lambdas). Bindings are added in parallel sets to help with shadowing issues.

Instances

AddBindings HermitC

AddBindings PrettyC

AddBindings (SnocPath crumb)

The bindings are just discarded.

(AddBindings c, AddBindings e) => AddBindings (ExtendContext c e)

The bindings are added to the base context and the extra context.

addBindingGroup :: (AddBindings c, ReadPath c Crumb) => CoreBind -> c -> c

Add all bindings in a binding group to a context.

addDefBinding :: (AddBindings c, ReadPath c Crumb) => Id -> c -> c

Add the binding for a recursive definition currently under examination. Note that because the expression may later be modified, the context only records the identifier, not the expression.

addDefBindingsExcept :: (AddBindings c, ReadPath c Crumb) => Int -> [(Id, CoreExpr)] -> c -> c

Add a list of recursive bindings to the context, except the nth binding in the list. The idea is to exclude the definition being descended into.

addLambdaBinding :: (AddBindings c, ReadPath c Crumb) => Var -> c -> c

Add a lambda bound variable to a context. All that is known is the variable, which may shadow something. If so, we don't worry about that here, it is instead checked during inlining.

addAltBindings :: (AddBindings c, ReadPath c Crumb) => [Var] -> c -> c

Add the variables bound by a DataCon in a case. They are all bound at the same depth.

addCaseWildBinding :: (AddBindings c, ReadPath c Crumb) => (Id, CoreExpr, CoreAlt) -> c -> c

Add a wildcard binding for a specific case alternative.

addForallBinding :: (AddBindings c, ReadPath c Crumb) => TyVar -> c -> c

Add a universally quantified type variable to a context.

Reading bindings from the context

class BoundVars c where

A class of contexts that stores the set of variables in scope that have been bound during the traversal.

Methods

boundVars :: c -> VarSet

Instances

BoundVars VarSet

BoundVars HermitC

BoundVars PrettyC

boundIn :: ReadBindings c => Var -> c -> Bool

Determine if a variable is bound in a context.

findBoundVars :: BoundVars c => Name -> c -> VarSet

List all variables bound in the context that match the given name.

class BoundVars c => ReadBindings c where

A class of contexts from which HERMIT bindings can be retrieved.

Methods

hermitDepth :: c -> BindingDepth

hermitBindings :: c -> Map Var HermitBinding

Instances

ReadBindings HermitC

lookupHermitBinding :: (ReadBindings c, Monad m) => Var -> c -> m HermitBinding

Lookup the binding for a variable in a context.

lookupHermitBindingDepth :: (ReadBindings c, Monad m) => Var -> c -> m BindingDepth

Lookup the depth of a variable's binding in a context.

lookupHermitBindingSite :: (ReadBindings c, Monad m) => Var -> BindingDepth -> c -> m HermitBindingSite

Lookup the binding for a variable in a context, ensuring it was bound at the specified depth.

Accessing the Global Reader Environment from the context

class HasGlobalRdrEnv c where

A class of contexts that store the Global Reader Environment.

Methods

hermitGlobalRdrEnv :: c -> GlobalRdrEnv

Instances

HasGlobalRdrEnv GlobalRdrEnv

HasGlobalRdrEnv HermitC

Accessing GHC rewrite rules from the context

class HasCoreRules c where

A class of contexts that store GHC rewrite rules.

Methods

hermitCoreRules :: c -> [CoreRule]

Instances

HasCoreRules HermitC

HasCoreRules [CoreRule]