Test.Lawful.Types

Type definitions (aliases) and basic utility functions used in the lawful-classes ecosystem.

Core types

type Laws m = [(String, Law m)]

Laws that hold for a specific Monad m.

They come with a name, and an action which may yield a Bool, denoting whether or not the law holds. It yield Nothing if the test should be discarded for the given input (when a generator is used).

type Law m = m (Maybe Bool)

A single law.

See Laws.

Utilities

discard :: Applicative m => Law m

Discard the current test-case.

assert :: Applicative m => Bool -> Law m

Assert a given Bool value is True.