Cryptol.TypeCheck.Monad

Documentation

data InferInput

Information needed for type inference.

Constructors

InferInput

Fields

inpRange :: Range

Location of program source

inpVars :: Map QName Schema

Variables that are in scope

inpTSyns :: Map QName TySyn

Type synonyms that are in scope

inpNewtypes :: Map QName Newtype

Newtypes in scope

inpNameSeeds :: NameSeeds

Private state of type-checker

inpMonoBinds :: Bool

Should local bindings without signatures be monomorphized?

Instances

Show InferInput

data NameSeeds

This is used for generating various names.

Constructors

NameSeeds

Fields

seedTVar :: !Int

seedGoal :: !Int

Instances

Show NameSeeds

nameSeeds :: NameSeeds

The initial seeds, used when checking a fresh program.

data InferOutput a

The results of type inference.

Constructors

InferFailed [(Range, Warning)] [(Range, Error)]

We found some errors

InferOK [(Range, Warning)] NameSeeds a

Type inference was successful.

Instances

Show a => Show (InferOutput a)

runInferM :: TVars a => InferInput -> InferM a -> IO (InferOutput a)

newtype InferM a

Constructors

IM

Fields

unIM :: ReaderT RO (StateT RW IO) a

Instances

Monad InferM

Functor InferM

MonadFix InferM

Applicative InferM

data DefLoc

Constructors

IsLocal

IsExternal

data RO

Read-only component of the monad.

Constructors

RO

Fields

iRange :: Range

Source code being analysed

iVars :: Map QName VarType

Type of variable that are in scope

iTVars :: [TParam]

Type variable that are in scope

iTSyns :: Map QName (DefLoc, TySyn)

Type synonyms that are in scope

iNewtypes :: Map QName (DefLoc, Newtype)

Newtype declarations in scope

NOTE: type synonyms take precedence over newtype. The reason is that we can define local type synonyms, but not local newtypes. So, either a type-synonym shadows a newtype, or it was declared at the top-level, but then there can't be a newtype with the same name (this should be caught by the renamer).

iSolvedHasLazy :: Map Int (Expr -> Expr)

NOTE: This field is lazy in an important way! It is the final version of iSolvedHas in RW, and the two are tied together through recursion. The field is here so that we can look thing up before they are defined, which is OK because we don't need to know the results until everything is done.

iMonoBinds :: Bool

When this flag is set to true, bindings that lack signatures in where-blocks will never be generalized. Bindings with type signatures, and all bindings at top level are unaffected.

data RW

Read-write component of the monad.

Constructors

RW

Fields

iErrors :: ![(Range, Error)]

Collected errors

iWarnings :: ![(Range, Warning)]

Collected warnings

iSubst :: !Subst

Accumulated substitution

iExistTVars :: [Map QName Type]

These keeps track of what existential type variables are available. When we start checking a function, we push a new scope for its arguments, and we pop it when we are done checking the function body. The front element of the list is the current scope, which is the only thing that will be modified, as follows. When we encounter a existential type variable: 1. we look in all scopes to see if it is already defined. 2. if it was not defined, we create a fresh type variable, and we add it to the current scope. 3. it is an error if we encounter an existential variable but we have no current scope.

iSolvedHas :: Map Int (Expr -> Expr)

Selector constraints that have been solved (ref. iSolvedSelectorsLazy)

iNameSeeds :: !NameSeeds

iCts :: !Goals

Ordinary constraints

iHasCts :: ![HasGoal]

Tuple/record projection constraints. The Int is the "name" of the constraint, used so that we can name it solution properly.

io :: IO a -> InferM a

inRange :: Range -> InferM a -> InferM a

The monadic computation is about the given range of source code. This is useful for error reporting.

inRangeMb :: Maybe Range -> InferM a -> InferM a

curRange :: InferM Range

This is the current range that we are working on.

recordError :: Error -> InferM ()

Report an error.

recordWarning :: Warning -> InferM ()

newGoal :: ConstraintSource -> Prop -> InferM Goal

newGoals :: ConstraintSource -> [Prop] -> InferM ()

Record some constraints that need to be solved. The string explains where the constraints came from.

getGoals :: InferM [Goal]

The constraints are removed, and returned to the caller. The substitution IS applied to them.

addGoals :: [Goal] -> InferM ()

Add a bunch of goals that need solving.

collectGoals :: InferM a -> InferM (a, [Goal])

Collect the goals emitted by the given sub-computation. Does not emit any new goals.

newHasGoal :: Selector -> Type -> Type -> InferM (Expr -> Expr)

Record a constraint that when we select from the first type, we should get a value of the second type. The returned function should be used to wrap the expression from which we are selecting (i.e., the record or tuple). Plese note that the resulting expression should not be forced before the constraint is solved.

addHasGoal :: HasGoal -> InferM ()

Add a previously generate has constrained

getHasGoals :: InferM [HasGoal]

Get the Has constraints. Each of this should either be solved, or added back using addHasGoal.

solveHasGoal :: Int -> (Expr -> Expr) -> InferM ()

Specify the solution (`Expr -> Expr`) for the given constraint (Int).

newName :: (NameSeeds -> (a, NameSeeds)) -> InferM a

newGoalName :: InferM Int

Generate a new name for a goal.

newTVar :: Doc -> Kind -> InferM TVar

Generate a new free type variable.

newTVar' :: Doc -> Set TVar -> Kind -> InferM TVar

Generate a new free type variable that depends on these additional type parameters.

newTParam :: Maybe QName -> Kind -> InferM TParam

Generate a new free type variable.

newType :: Doc -> Kind -> InferM Type

Generate an unknown type. The doc is a note about what is this type about.

unify :: Type -> Type -> InferM [Prop]

Record that the two types should be syntactically equal.

applySubst :: TVars t => t -> InferM t

Apply the accumulated substitution to something with free type variables.

getSubst :: InferM Subst

Get the substitution that we have accumulated so far.

extendSubst :: Subst -> InferM ()

Add to the accumulated substitution.

varsWithAsmps :: InferM (Set TVar)

Variables that are either mentioned in the environment or in a selector constraint.

lookupVar :: QName -> InferM VarType

Lookup the type of a variable.

lookupTVar :: QName -> InferM (Maybe Type)

Lookup a type variable. Return Nothing if there is no such variable in scope, in which case we must be dealing with a type constant.

lookupTSyn :: QName -> InferM (Maybe TySyn)

Lookup the definition of a type synonym.

lookupNewtype :: QName -> InferM (Maybe Newtype)

Lookup the definition of a newtype

existVar :: QName -> Kind -> InferM Type

Check if we already have a name for this existential type variable and, if so, return the definition. If not, try to create a new definition, if this is allowed. If not, returns nothing.

getTSyns :: InferM (Map QName (DefLoc, TySyn))

Returns the type synonyms that are currently in scope.

getNewtypes :: InferM (Map QName (DefLoc, Newtype))

Returns the newtype declarations that are in scope.

getTVars :: InferM (Set QName)

Get the set of bound type variables that are in scope.

getBoundInScope :: InferM (Set TVar)

Return the keys of the bound variables that are in scope.

getMonoBinds :: InferM Bool

Retrieve the value of the `mono-binds` option.

checkTShadowing :: String -> QName -> InferM ()

We disallow shadowing between type synonyms and type variables because it is confusing. As a bonus, in the implementation we don't need to worry about where we lookup things (i.e., in the variable or type synonym environment.

withTParam :: TParam -> InferM a -> InferM a

The sub-computation is performed with the given type parameter in scope.

withTParams :: [TParam] -> InferM a -> InferM a

withTySyn :: TySyn -> InferM a -> InferM a

The sub-computation is performed with the given type-synonym in scope.

withNewtype :: Newtype -> InferM a -> InferM a

withVarType :: QName -> VarType -> InferM a -> InferM a

The sub-computation is performed with the given variable in scope.

withVarTypes :: [(QName, VarType)] -> InferM a -> InferM a

withVar :: QName -> Schema -> InferM a -> InferM a

withMonoType :: (QName, Located Type) -> InferM a -> InferM a

The sub-computation is performed with the given variables in scope.

withMonoTypes :: Map QName (Located Type) -> InferM a -> InferM a

The sub-computation is performed with the given variables in scope.

withDecls :: ([TySyn], Map QName Schema) -> InferM a -> InferM a

The sub-computation is performed with the given type synonyms and variables in scope.

inNewScope :: InferM a -> InferM a

Perform the given computation in a new scope (i.e., the subcomputation may use existential type variables).

newtype KindM a

Constructors

KM

Fields

unKM :: ReaderT KRO (StateT KRW InferM) a

Instances

Monad KindM

Functor KindM

Applicative KindM

data KRO

Constructors

KRO

Fields

lazyTVars :: Map QName Type

lazy map, with tyvars.

allowWild :: Bool

are type-wild cards allowed?

data KRW

Constructors

KRW

Fields

typeParams :: Map QName Kind

kinds of (known) vars.

runKindM

Arguments

:: Bool

-> [(QName, Maybe Kind, Type)]

See comment

-> KindM a

-> InferM (a, Map QName Kind)

The arguments to this function are as follows:

(type param. name, kind signature (opt.), a type representing the param)

The type representing the parameter is just a thunk that we should not force. The reason is that the type depnds on the kind of parameter, that we are in the process of computing.

As a result we return the value of the sub-computation and the computed kinds of the type parameters.

data LkpTyVar

This is what's returned when we lookup variables during kind checking.

Constructors

TLocalVar Type (Maybe Kind)

Locally bound variable.

TOuterVar Type

An outer binding.

kLookupTyVar :: QName -> KindM (Maybe LkpTyVar)

Check if a name refers to a type variable.

kWildOK :: KindM Bool

Are type wild-cards OK in this context?

kRecordError :: Error -> KindM ()

Reports an error.

kRecordWarning :: Warning -> KindM ()

kNewType :: Doc -> Kind -> KindM Type

Generate a fresh unification variable of the given kind.

kLookupTSyn :: QName -> KindM (Maybe TySyn)

Lookup the definition of a type synonym.

kLookupNewtype :: QName -> KindM (Maybe Newtype)

Lookup the definition of a newtype.

kExistTVar :: QName -> Kind -> KindM Type

kInstantiateT :: Type -> [(TParam, Type)] -> KindM Type

Replace the given bound variables with concrete types.

kSetKind :: QName -> Kind -> KindM ()

Record the kind for a local type variable. This assumes that we already checked that there was no other valid kind for the variable (if there was one, it gets over-written).

kInRange :: Range -> KindM a -> KindM a

The sub-computation is about the given range of the source code.

kNewGoals :: ConstraintSource -> [Prop] -> KindM ()

kInInferM :: InferM a -> KindM a

module Cryptol.TypeCheck.InferTypes