edu.rice.cs.plt.collect
Class ConsVisitor<T,Ret>

java.lang.Object
  edu.rice.cs.plt.collect.ConsVisitor<T,Ret>

All Implemented Interfaces:

Lambda<ConsList<? extends T>,Ret>

public abstract class ConsVisitor<T,Ret>
extends java.lang.Object
implements Lambda<ConsList<? extends T>,Ret>

A visitor for ConsLists. Implementations handle the two list variants: ConsList.Empty and ConsList.Nonempty. For convenience, visitors may also be treated as Lambdas -- the value method is implemented to apply the visitor. A number of standard list visitors are also provided, either as static fields or static methods.

Constructor Summary

ConsVisitor()

Method Summary

static <T> ConsVisitor<T,ConsList<? extends T>>	append(ConsList<? extends T> rest) Appends the given list to the end of another list
static <T> ConsVisitor<T,ConsList<T>>	filter(Predicate<? super T> pred) Filters a list to contain only those elements accepted by the given predicate
static <T> ConsVisitor<T,T>	first() Attempt to access the first of the given list (throws an exception in the empty case).
abstract Ret	forEmpty() Handle an empty list
abstract Ret	forNonempty(T first, ConsList<? extends T> rest) Handle a nonempty list
static <S,T> ConsVisitor<S,ConsList<T>>	map(Lambda<? super S,? extends T> lambda) Produces a new list by applying the given lambda to each of a list's elements
static <T> ConsVisitor<T,ConsList<? extends T>>	rest() Attempt to access the rest of the given list (throws an exception in the empty case).
static <T> ConsVisitor<T,ConsList<? extends T>>	reverse() Reverses the order of the elements in a list
Ret	value(ConsList<? extends T> list) Invoke list.apply(this)

Methods inherited from class java.lang.Object

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

Constructor Detail

ConsVisitor

public ConsVisitor()

Method Detail

forEmpty

public abstract Ret forEmpty()

Handle an empty list

forNonempty

public abstract Ret forNonempty(T first,
                                ConsList<? extends T> rest)

Handle a nonempty list

value

public Ret value(ConsList<? extends T> list)

Invoke list.apply(this)

Specified by:

value in interface Lambda<ConsList<? extends T>,Ret>

first

public static final <T> ConsVisitor<T,T> first()

Attempt to access the first of the given list (throws an exception in the empty case).

rest

public static final <T> ConsVisitor<T,ConsList<? extends T>> rest()

Attempt to access the rest of the given list (throws an exception in the empty case).

reverse

public static <T> ConsVisitor<T,ConsList<? extends T>> reverse()

Reverses the order of the elements in a list

append

public static <T> ConsVisitor<T,ConsList<? extends T>> append(ConsList<? extends T> rest)

Appends the given list to the end of another list

filter

public static <T> ConsVisitor<T,ConsList<T>> filter(Predicate<? super T> pred)

Filters a list to contain only those elements accepted by the given predicate

map

public static <S,T> ConsVisitor<S,ConsList<T>> map(Lambda<? super S,? extends T> lambda)

Produces a new list by applying the given lambda to each of a list's elements