Data.Annotation

An Annotation is attached to a LocatedException. They're essentially a dynamically typed value with a convenient IsString instance. I'd recommend using something like Data.Aeson.Value or possibly something more strongly typed.

Documentation

newtype CallStackAnnotation

A wrapper type for putting a CallStack into an Annotation. We need this because CallStack does not have an Eq instance.

Since: 0.1.0.0

Constructors

CallStackAnnotation

Fields

• unCallStackAnnotation :: [(String, SrcLoc)]

Instances

Eq CallStackAnnotation

Defined in Data.Annotation

Methods

(==) :: CallStackAnnotation -> CallStackAnnotation -> Bool

(/=) :: CallStackAnnotation -> CallStackAnnotation -> Bool

Show CallStackAnnotation

Defined in Data.Annotation

Methods

showsPrec :: Int -> CallStackAnnotation -> ShowS

show :: CallStackAnnotation -> String

showList :: [CallStackAnnotation] -> ShowS

data Annotation where

An Annotation is a wrapper around a value that includes a Typeable constraint so we can later unpack it. It is essentially a 'Dynamic, but we also include Show and Eq so it's more useful.

Since: 0.1.0.0

Constructors

Annotation :: AnnC a => a -> Annotation

Instances

Eq Annotation

Since: 0.1.0.0

Defined in Data.Annotation

Methods

(==) :: Annotation -> Annotation -> Bool

(/=) :: Annotation -> Annotation -> Bool

Show Annotation

Since: 0.1.0.0

Defined in Data.Annotation

Methods

showsPrec :: Int -> Annotation -> ShowS

show :: Annotation -> String

showList :: [Annotation] -> ShowS

IsString Annotation

Since: 0.1.0.0

Defined in Data.Annotation

Methods

fromString :: String -> Annotation

type AnnC a = (Typeable a, Eq a, Show a)

The constraints that the value inside an Annotation must have.

We want Typeable so we can do cast and potentially get more useful information out of it.

Since: 0.1.0.0

toAnnotation :: AnnC a => a -> Annotation

Wrap a value in an Annotation.

Since: 0.1.0.0

castAnnotation :: forall a. Typeable a => Annotation -> Maybe a

Attempt to cast the underlying value out of an Annotation.

Since: 0.1.0.0

tryAnnotation :: forall a. Typeable a => Annotation -> Either a Annotation

Attempt to cast the underlying value out of an Annotation. Returns the original Annotation if the cast isn't right.

Since: 0.1.0.0

tryAnnotations :: forall a. Typeable a => [Annotation] -> ([a], [Annotation])

Attempt to cast list of Annotation into the given type. Any Annotation that is not in that form is left untouched.

Since: 0.1.0.0

annotationTypes :: [Annotation] -> Set TypeRep

Returns the Set of types that are in the given annotations.

Since: 0.1.0.0

mapAnnotation :: (AnnC a, AnnC b) => (a -> b) -> Annotation -> Maybe Annotation

Map a function over the given Annotation. If the types don't match up, then the whole thing returns Nothing.

Since: 0.1.0.0

mapMaybeAnnotation :: (AnnC a, AnnC b) => (a -> b) -> Annotation -> Annotation

Map a function over the Annotation, leaving it unchanged if the types don't match.

Since: 0.1.0.0

callStackAnnotation :: HasCallStack => Annotation

Grab an Annotation corresponding to the CallStack that is currently in scope.

Since: 0.1.0.0

callStackToAnnotation :: CallStack -> Annotation

Stuff a CallStack into an Annotation via the CallStackAnnotation newtype wrapper.

Since: 0.1.0.0

callStackFromAnnotation :: CallStackAnnotation -> CallStack

Attempt to convert an Annotation back into a CallStack.

Since: 0.1.0.0

callStackInAnnotations :: [Annotation] -> ([CallStack], [Annotation])

Extract the CallStacks from the [Annotation]. Any Annotation not corresponding to a CallStack will be in the second element of the tuple.

Since: 0.1.0.0

module Data.Proxy