Generics.EMGM.Functions.Meta

Summary: Functions for extracting meta-information about the representation.

Embedding-Projection Pair

class HasEP a b | a -> b where

A class to reveal the embedding-projection pair for a given datatype and its isomorphic representation type.

Methods

epOf :: a -> EP a b

The parameter is never evaluated, so undefined is acceptable.

Instances

HasEP Bool BoolS

HasEP () Tuple0S

HasEP [a] (ListS a)

Integral a => HasEP (Ratio a) (RatioS a)

HasEP (Maybe a) (MaybeS a)

HasEP (Either a b) (EitherS a b)

HasEP (a, b) (Tuple2S a b)

HasEP (a, b, c) (Tuple3S a b c)

HasEP (a, b, c, d) (Tuple4S a b c d)

HasEP (a, b, c, d, e) (Tuple5S a b c d e)

HasEP (a, b, c, d, e, f) (Tuple6S a b c d e f)

HasEP (a, b, c, d, e, f, h) (Tuple7S a b c d e f h)

Constructor Description

newtype Con a

The type of a generic function that takes one value and returns an optional constructor description.

Constructors

Con

Fields

selConstructor :: a -> Maybe ConDescr

Instances

Generic Con

conDescr :: Rep Con a => a -> Maybe ConDescr

Returns a constructor description if the value is not a primitive. The argument is not evaluated and may be undefined.

Label Descriptions

newtype Lbls a

The type of a generic function that takes a boolean to limit recursion and a value and returns a list of label descriptions for that constructor.

Constructors

Lbls

Fields

selLabels :: Bool -> a -> [LblDescr]

Instances

Generic Lbls

lblDescrs :: Rep Lbls a => a -> [LblDescr]

Returns a list of descriptions for all labels in the head constructor. Does not recurse into the children. The argument is not evaluated and may be undefined.