parameterized-utils-2.1.0: Classes and data structures for working with data-kind indexed types

Copyright(c) Galois Inc 2014-2019
MaintainerJoe Hendrix <jhendrix@galois.com>
Safe HaskellTrustworthy
LanguageHaskell2010

Data.Parameterized.SymbolRepr

Contents

Description

Description : a type family for representing a type-level string (AKA symbol) at runtime

This defines a type family SymbolRepr for representing a type-level string (AKA symbol) at runtime. This can be used to branch on a type-level value.

The TestEquality and OrdF instances for SymbolRepr are implemented using unsafeCoerce. This should be typesafe because we maintain the invariant that the string value contained in a SymbolRepr value matches its static type.

At the type level, symbols have very few operations, so SymbolRepr correspondingly has very few functions that manipulate them.

Synopsis

SymbolRepr

data SymbolRepr (nm :: Symbol) Source #

A runtime representation of a GHC type-level symbol.

Instances
TestEquality SymbolRepr Source # 
Instance details

Defined in Data.Parameterized.SymbolRepr

Methods

testEquality :: SymbolRepr a -> SymbolRepr b -> Maybe (a :~: b) #

HashableF SymbolRepr Source # 
Instance details

Defined in Data.Parameterized.SymbolRepr

ShowF SymbolRepr Source # 
Instance details

Defined in Data.Parameterized.SymbolRepr

Methods

withShow :: p SymbolRepr -> q tp -> (Show (SymbolRepr tp) -> a) -> a Source #

showF :: SymbolRepr tp -> String Source #

showsPrecF :: Int -> SymbolRepr tp -> String -> String Source #

OrdF SymbolRepr Source # 
Instance details

Defined in Data.Parameterized.SymbolRepr

IsRepr SymbolRepr Source # 
Instance details

Defined in Data.Parameterized.WithRepr

Methods

withRepr :: SymbolRepr a -> (KnownRepr SymbolRepr a -> r) -> r Source #

KnownSymbol s => KnownRepr SymbolRepr (s :: Symbol) Source # 
Instance details

Defined in Data.Parameterized.SymbolRepr

Eq (SymbolRepr x) Source # 
Instance details

Defined in Data.Parameterized.SymbolRepr

Methods

(==) :: SymbolRepr x -> SymbolRepr x -> Bool #

(/=) :: SymbolRepr x -> SymbolRepr x -> Bool #

Ord (SymbolRepr x) Source # 
Instance details

Defined in Data.Parameterized.SymbolRepr

Show (SymbolRepr nm) Source # 
Instance details

Defined in Data.Parameterized.SymbolRepr

Methods

showsPrec :: Int -> SymbolRepr nm -> ShowS #

show :: SymbolRepr nm -> String #

showList :: [SymbolRepr nm] -> ShowS #

Hashable (SymbolRepr nm) Source # 
Instance details

Defined in Data.Parameterized.SymbolRepr

Methods

hashWithSalt :: Int -> SymbolRepr nm -> Int #

hash :: SymbolRepr nm -> Int #

symbolRepr :: SymbolRepr nm -> Text Source #

The underlying text representation of the symbol

knownSymbol :: KnownSymbol s => SymbolRepr s Source #

Generate a value representative for the type level symbol.

someSymbol :: Text -> Some SymbolRepr Source #

Generate a symbol representative at runtime. The type-level symbol will be abstract, as it is hidden by the Some constructor.

Re-exports

data Symbol #

(Kind) This is the kind of type-level symbols. Declared here because class IP needs it

Instances
SingKind Symbol

Since: base-4.9.0.0

Instance details

Defined in GHC.Generics

Associated Types

type DemoteRep Symbol :: Type

Methods

fromSing :: Sing a -> DemoteRep Symbol

KnownSymbol a => SingI (a :: Symbol)

Since: base-4.9.0.0

Instance details

Defined in GHC.Generics

Methods

sing :: Sing a

TestEquality SymbolRepr Source # 
Instance details

Defined in Data.Parameterized.SymbolRepr

Methods

testEquality :: SymbolRepr a -> SymbolRepr b -> Maybe (a :~: b) #

HashableF SymbolRepr Source # 
Instance details

Defined in Data.Parameterized.SymbolRepr

ShowF SymbolRepr Source # 
Instance details

Defined in Data.Parameterized.SymbolRepr

Methods

withShow :: p SymbolRepr -> q tp -> (Show (SymbolRepr tp) -> a) -> a Source #

showF :: SymbolRepr tp -> String Source #

showsPrecF :: Int -> SymbolRepr tp -> String -> String Source #

OrdF SymbolRepr Source # 
Instance details

Defined in Data.Parameterized.SymbolRepr

IsRepr SymbolRepr Source # 
Instance details

Defined in Data.Parameterized.WithRepr

Methods

withRepr :: SymbolRepr a -> (KnownRepr SymbolRepr a -> r) -> r Source #

KnownSymbol n => Reifies (n :: Symbol) String 
Instance details

Defined in Data.Reflection

Methods

reflect :: proxy n -> String #

KnownSymbol s => KnownRepr SymbolRepr (s :: Symbol) Source # 
Instance details

Defined in Data.Parameterized.SymbolRepr

data Sing (s :: Symbol) 
Instance details

Defined in GHC.Generics

data Sing (s :: Symbol) where
type DemoteRep Symbol 
Instance details

Defined in GHC.Generics

type DemoteRep Symbol = String

class KnownSymbol (n :: Symbol) #

This class gives the string associated with a type-level symbol. There are instances of the class for every concrete literal: "hello", etc.

Since: base-4.7.0.0

Minimal complete definition

symbolSing