Matcher

Documentation

data Matcher a b

A composable abstraction for checking or converting a context value.

Instances

Arrow Matcher

Profunctor Matcher

Category * Matcher

Monad (Matcher a)

Functor (Matcher a)

Applicative (Matcher a)

Alternative (Matcher a)

MonadPlus (Matcher a)

run :: Matcher a b -> a -> Either Text b

Converts the matcher into a conversion function, which results in either a successful result or a failure.

equals :: Eq a => a -> Matcher a ()

Tests the matched value on equality with the provided value.

satisfies :: (a -> Bool) -> Matcher a ()

Checks whether the matched value satisfies the provided predicate.

converts :: (a -> Either Text b) -> Matcher a b

Tries to convert the matched value to an output value, with Either encoding the success or failure of the conversion.

whatever :: Matcher a ()

The matcher, which is always satisfied.