Package com.jnape.palatable.lambda.monoid.builtin

Class Present<A>

java.lang.Object

com.jnape.palatable.lambda.monoid.builtin.Present<A>

Type Parameters:

A - the Maybe value parameter type

All Implemented Interfaces:

Fn1<Semigroup<A>,Fn1<Maybe<A>,Fn1<Maybe<A>,Maybe<A>>>>, Fn2<Semigroup<A>,Maybe<A>,Fn1<Maybe<A>,Maybe<A>>>, Fn3<Semigroup<A>,Maybe<A>,Maybe<A>,Maybe<A>>, MonoidFactory<Semigroup<A>,Maybe<A>>, SemigroupFactory<Semigroup<A>,Maybe<A>>, Applicative<Fn1<Maybe<A>,Fn1<Maybe<A>,Maybe<A>>>,Fn1<Semigroup<A>,?>>, Cartesian<Semigroup<A>,Fn1<Maybe<A>,Fn1<Maybe<A>,Maybe<A>>>,Fn1<?,?>>, Cocartesian<Semigroup<A>,Fn1<Maybe<A>,Fn1<Maybe<A>,Maybe<A>>>,Fn1<?,?>>, Contravariant<Semigroup<A>,Profunctor<?,Fn1<Maybe<A>,Fn1<Maybe<A>,Maybe<A>>>,Fn1<?,?>>>, Functor<Fn1<Maybe<A>,Fn1<Maybe<A>,Maybe<A>>>,Fn1<Semigroup<A>,?>>, Profunctor<Semigroup<A>,Fn1<Maybe<A>,Fn1<Maybe<A>,Maybe<A>>>,Fn1<?,?>>, Monad<Fn1<Maybe<A>,Fn1<Maybe<A>,Maybe<A>>>,Fn1<Semigroup<A>,?>>, MonadReader<Semigroup<A>,Fn1<Maybe<A>,Fn1<Maybe<A>,Maybe<A>>>,Fn1<Semigroup<A>,?>>, MonadRec<Fn1<Maybe<A>,Fn1<Maybe<A>,Maybe<A>>>,Fn1<Semigroup<A>,?>>, MonadWriter<Semigroup<A>,Fn1<Maybe<A>,Fn1<Maybe<A>,Maybe<A>>>,Fn1<Semigroup<A>,?>>

public final class Present<A>
extends java.lang.Object
implements MonoidFactory<Semigroup<A>,Maybe<A>>

A Monoid instance formed by Maybe<A> and a semigroup over A. The application to two Maybe values is presence-biased, such that for a given Maybe x and y:

• if x is present and y is absent, the result is x
• if x is absent, the result is y
• if both x and y are present, the result is the application of the x and y values in terms of the provided semigroup, wrapped in Maybe.just(A)

See Also:

Monoid, Absent, Maybe

Field Summary

Fields

Modifier and Type	Field	Description
private static Present<?>	INSTANCE

Constructor Summary

Constructors

Modifier	Constructor	Description
private	Present()

Method Summary

Modifier and Type	Method	Description
Monoid<Maybe<A>>	checkedApply(Semigroup<A> aSemigroup)	Invoke this function with the given argument, potentially throwing any Throwable.
static <A> Present<A>	present()
static <A> Monoid<Maybe<A>>	present(Semigroup<A> semigroup)
static <A> Fn1<Maybe<A>,Maybe<A>>	present(Semigroup<A> aSemigroup, Maybe<A> x)
static <A> Maybe<A>	present(Semigroup<A> semigroup, Maybe<A> x, Maybe<A> y)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface com.jnape.palatable.lambda.functions.Fn1

andThen, carry, cartesian, censor, choose, cocartesian, diMap, diMapR, discardL, flatMap, fmap, lazyZip, listens, local, pure, self, thunk, toFunction, trampolineM, zip, zip

Methods inherited from interface com.jnape.palatable.lambda.functions.Fn2

toBiFunction

Methods inherited from interface com.jnape.palatable.lambda.functions.Fn3

apply, checkedApply, compose, contraMap, diMapL, discardR, flip, uncurry, widen

Methods inherited from interface com.jnape.palatable.lambda.functor.Functor

coerce

Methods inherited from interface com.jnape.palatable.lambda.functions.specialized.MonoidFactory

apply, apply

Methods inherited from interface com.jnape.palatable.lambda.functions.specialized.SemigroupFactory

checkedApply

Field Detail

INSTANCE

private static final Present<?> INSTANCE

Constructor Detail

Present

private Present()

Method Detail

checkedApply

public Monoid<Maybe<A>> checkedApply(Semigroup<A> aSemigroup)

Description copied from interface: Fn2

Invoke this function with the given argument, potentially throwing any Throwable.

Specified by:

checkedApply in interface Fn1<Semigroup<A>,Fn1<Maybe<A>,Fn1<Maybe<A>,Maybe<A>>>>

Specified by:

checkedApply in interface Fn2<Semigroup<A>,Maybe<A>,Fn1<Maybe<A>,Maybe<A>>>

Specified by:

checkedApply in interface MonoidFactory<Semigroup<A>,Maybe<A>>

Specified by:

checkedApply in interface SemigroupFactory<Semigroup<A>,Maybe<A>>

Parameters:

aSemigroup - the argument

Returns:

the result of the function application

present

public static <A> Present<A> present()

present

public static <A> Monoid<Maybe<A>> present(Semigroup<A> semigroup)

present

public static <A> Fn1<Maybe<A>,Maybe<A>> present(Semigroup<A> aSemigroup,
                                                       Maybe<A> x)

present

public static <A> Maybe<A> present(Semigroup<A> semigroup,
                                   Maybe<A> x,
                                   Maybe<A> y)