Data.Tuple.Ops.Uncons

This module define uncons. Examples are given below:

>>> uncons (1::Int)
(1,())

>>> uncons (1::Int,'a')
(1,'a')

>>> uncons (True,'a', "S")
(True,('a',"S"))

Documentation

uncons :: Unconsable a b c => a -> (b, c)

uncons takes primitive, pair, tuple, and produces a pair of its first data and the rest elements.

type family Uncons a where ...

calculate the result type of uncons

Equations

Uncons (a, b) = (a, b)

Uncons (a, b, c) = (a, (b, c))

Uncons (a, b, c, d) = (a, (b, c, d))

Uncons (a, b, c, d, e) = (a, (b, c, d, e))

Uncons (a, b, c, d, e, f) = (a, (b, c, d, e, f))

Uncons (a, b, c, d, e, f, g) = (a, (b, c, d, e, f, g))

Uncons (a, b, c, d, e, f, g, h) = (a, (b, c, d, e, f, g, h))

Uncons (a, b, c, d, e, f, g, h, i) = (a, (b, c, d, e, f, g, h, i))

Uncons (a, b, c, d, e, f, g, h, i, j) = (a, (b, c, d, e, f, g, h, i, j))

Uncons (a, b, c, d, e, f, g, h, i, j, k) = (a, (b, c, d, e, f, g, h, i, j, k))

Uncons (a, b, c, d, e, f, g, h, i, j, k, l) = (a, (b, c, d, e, f, g, h, i, j, k, l))

Uncons (a, b, c, d, e, f, g, h, i, j, k, l, m) = (a, (b, c, d, e, f, g, h, i, j, k, l, m))

Uncons (a, b, c, d, e, f, g, h, i, j, k, l, m, n) = (a, (b, c, d, e, f, g, h, i, j, k, l, m, n))

Uncons (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o) = (a, (b, c, d, e, f, g, h, i, j, k, l, m, n, o))

Uncons (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p) = (a, (b, c, d, e, f, g, h, i, j, k, l, m, n, o, p))

Uncons a = (a, ())

type Unconsable a b c = (Generic a, Generic b, Generic c, Uncons a ~ (b, c), Rep a ~ D1 (MetaOfD1 (Rep a)) (UnD1 (Rep a)), Rep b ~ D1 (MetaOfD1 (Rep b)) (UnD1 (Rep b)), Rep c ~ D1 (MetaOfD1 (Rep c)) (UnD1 (Rep c)), UnconsableR (UnD1 (Rep a)), HeadR (UnD1 (Rep a)) ~ UnD1 (Rep b), TailR (UnD1 (Rep a)) ~ UnD1 (Rep c))

A constraint on any unconsable data type, where a is the input type, and (b,c) is the output type