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| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 | 45x 5x 5x 115x 115x | import {addLawSets, Law, lawTests} from '#law'
import {Contravariant as CN} from '@effect/typeclass'
import {flow, identity, pipe} from 'effect'
import type {TypeLambda} from 'effect/HKT'
import {invariantLaws} from './Invariant.js'
import type {BuildParameterized} from './given.js'
import {unfoldGiven} from './given.js'
/**
* Typeclass laws for `Contravariant` and its requirement: `Invariant`.
* @category typeclass laws
*/
export const contravariantLaws: BuildParameterized<ContravariantTypeLambda> = (
given,
suffix?,
) => {
const {F, equalsFa, fa, ba, cb, equalsFc} = unfoldGiven(given)
return pipe(
lawTests(
`Contravariant${suffix ?? ''}`,
Law(
'identity',
'contramap(id) = id',
fa,
)(fa => equalsFa(F.contramap(fa, identity), fa)),
Law(
'composition',
'fa ▹ contramap(ba) ▹ contramap(cb) = fa ▹ contramap(ba ∘ cb)',
fa,
ba,
cb,
)((fa, ba, cb) =>
equalsFc(
pipe(fa, F.contramap(ba), F.contramap(cb)),
pipe(fa, F.contramap(flow(cb, ba))),
),
),
),
pipe(given, invariantLaws, addLawSets),
)
}
/**
* Type lambda for the `Contravariant` typeclass.
* @category type lambda
*/
export interface ContravariantTypeLambda extends TypeLambda {
readonly type: CN.Contravariant<this['Target'] & TypeLambda>
}
declare module './given.js' {
interface ParameterizedLambdas {
Contravariant: ContravariantTypeLambda
}
}
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