Class Head<A>

java.lang.Object

com.jnape.palatable.lambda.functions.builtin.fn1.Head<A>

Type Parameters:

A - the Iterable element type

All Implemented Interfaces:

Fn1<Iterable<A>, Maybe<A>>, Applicative<Maybe<A>, Fn1<Iterable<A>, ?>>, Cartesian<Iterable<A>, Maybe<A>, Fn1<?,?>>, Cocartesian<Iterable<A>, Maybe<A>, Fn1<?,?>>, Contravariant<Iterable<A>, Profunctor<?,Maybe<A>,Fn1<?,?>>>, Functor<Maybe<A>, Fn1<Iterable<A>, ?>>, Profunctor<Iterable<A>, Maybe<A>, Fn1<?,?>>, Monad<Maybe<A>, Fn1<Iterable<A>, ?>>, MonadReader<Iterable<A>, Maybe<A>, Fn1<Iterable<A>, ?>>, MonadRec<Maybe<A>, Fn1<Iterable<A>, ?>>, MonadWriter<Iterable<A>, Maybe<A>, Fn1<Iterable<A>, ?>>

public final class Head<A>
extends Object
implements Fn1<Iterable<A>, Maybe<A>>

Retrieve the head element of an Iterable, wrapped in an Maybe. If the Iterable is empty, the result is Maybe.nothing().

Field Summary

Fields

Modifier and Type	Field	Description
private static final Head<?>	INSTANCE

Constructor Summary

Constructors

Modifier	Constructor	Description
private	Head()

Method Summary

Modifier and Type	Method	Description
Maybe<A>	checkedApply(Iterable<A> as)	Invoke this function with the given argument, potentially throwing any Throwable.
static <A> Head<A>	head()
static <A> Maybe<A>	head(Iterable<A> as)

Methods inherited from class Object

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

Methods inherited from interface Fn1

andThen, apply, carry, cartesian, censor, choose, cocartesian, compose, contraMap, diMap, diMapL, diMapR, discardL, discardR, flatMap, fmap, lazyZip, listens, local, pure, self, thunk, toFunction, trampolineM, widen, zip, zip

Methods inherited from interface Functor

coerce

Field Details

INSTANCE

private static final Head<?> INSTANCE

Constructor Details

Head

private Head()

Method Details

checkedApply

public Maybe<A> checkedApply(Iterable<A> as)

Description copied from interface: Fn1

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

Specified by:

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

Parameters:

as - the argument

Returns:

the result of the function application

head

public static <A> Head<A> head()

head

public static <A> Maybe<A> head(Iterable<A> as)