Safe Haskell	None

Prelude.Type.Match

Synopsis

Documentation

class Match a b p | a b -> pSource

Match

Used by Case to match patterns.

Match +a ?b -c Given a type a, match it with a pattern b, unifying the type variables. If it matches, c is True, otherwise c is False.

>>> value (T :: Match (Just True) (Just x) p => T '(x, p)) :: (Bool, Bool)
(True, True)

Match is in a seperate module because I use IncoherentInstances to match type variables.

Instances

Match Bool False True False
(~ Bool false False, ~ Bool match True) => Match Bool False false match
Match Bool True False False
(~ Bool true True, ~ Bool match True) => Match Bool True true match
Match Ordering LT EQ False
Match Ordering LT GT False
(~ Ordering lt LT, ~ Bool match True) => Match Ordering LT lt match
Match Ordering EQ LT False
Match Ordering EQ GT False
(~ Ordering eq EQ, ~ Bool match True) => Match Ordering EQ eq match
Match Ordering GT LT False
Match Ordering GT EQ False
(~ Ordering gt GT, ~ Bool match True) => Match Ordering GT gt match
~ () a b => Match () a b True
(~ k a b, ~ Bool p True) => Match k a b p
(~ Integer zeros Zeros, ~ Bool true True) => Match Integer Zeros zeros true
Match Integer Zeros Ones False
(~ Integer ones Ones, ~ Bool true True) => Match Integer Ones ones true
Match Integer Ones Zeros False
Match Integer Zeros (Zero j) False
Match Integer Zeros (One j) False
Match Integer Ones (Zero j) False
Match Integer Ones (One j) False
(~ Integer zero_j (Zero j), Match Integer i j p) => Match Integer (Zero i) zero_j p
Match Integer (Zero i) Zeros False
Match Integer (Zero i) Ones False
(~ Integer one_j (One j), Match Integer i j p) => Match Integer (One i) one_j p
Match Integer (One i) Zeros False
Match Integer (One i) Ones False
Match Integer (Zero i) (One i) False
Match Integer (One i) (Zero j) False
(~ [k] nil ([] k), ~ Bool true True) => Match [k] ([] k) nil true
(~ (Maybe k) nothing (Nothing k), ~ Bool true true) => Match (Maybe k) (Nothing k) nothing true
Match (Maybe k) (Nothing k) (Just k a) False
Match [k] ([] k) (: k x xs) False
(~ (Maybe k) just_b (Just k b), Match k a b p) => Match (Maybe k) (Just k a) just_b p
~ Bool false False => Match (Maybe k) (Just k a) (Nothing k) false
(~ [k] cons (: k y ys), Match k x y m, If Constraint m (Match [k] xs ys p) (~ Bool p False)) => Match [k] (: k x xs) cons p
Match [k] (: k x xs) ([] k) False
(~ (Either k k1) right_b (Right k k1 b), Match k1 a b p) => Match (Either k k1) (Right k k1 a) right_b p
(~ (Either k k1) left_b (Left k k1 b), Match k a b p) => Match (Either k k1) (Left k k1 a) left_b p
Match (Either k k1) (Right k k1 a) (Left k k1 b) False
Match (Either k k1) (Left k k1 a) (Right k k1 b) False
(~ ((,) k k1) e_f ((,) k k1 e f), Match k a e p, Match k1 b f q, ~ Bool r (&& p q)) => Match ((,) k k1) ((,) k k1 a b) e_f r
(~ ((,,) k k1 k2) e_f_g ((,,) k k1 k2 e f g), Match k a e p, Match k1 b f q, Match k2 c g r, ~ Bool (&& p q) s, ~ Bool (&& r s) t) => Match ((,,) k k1 k2) ((,,) k k1 k2 a b c) e_f_g t
(~ ((,,,) k k1 k2 k3) e_f_g_h ((,,,) k k1 k2 k3 e f g h), Match k a e p, Match k1 b f q, Match k2 c g r, Match k3 d h s, ~ Bool (&& p q) t, ~ Bool (&& r s) u, ~ Bool (&& t u) v) => Match ((,,,) k k1 k2 k3) ((,,,) k k1 k2 k3 a b c d) e_f_g_h v