ch.epfl.cs108

Interface Sq<T>

Type Parameters:

T - the type of the sequence elements

public interface Sq<T>

A lazy, immutable and possibly infinite sequence of elements.

Method Summary

Modifier and Type	Method and Description
Sq<T>	concat(Sq<T> that) Return a sequence consisting of all the elements of this sequence, followed by all the elements of the given sequence that.
static <T> Sq<T>	constant(T v) Return an infinite sequence consisting of a single element repeated infintely.
Sq<T>	dropWhile(Predicate<T> p) Return a sequence consisting of the elements of this sequence except all the leading ones satisfying predicate p.
static <T> Sq<T>	empty() Return an empty sequence.
default T	findFirst(Predicate<T> p) Return the first element of this sequence satisfying predicate p.
T	head() Return the head (first element) of this sequence.
boolean	isEmpty() Return true if this sequence contains no elements.
static <T> Sq<T>	iterate(T start, UnaryOperator<T> next) Returns an infinite sequence produced by iterative application of a function next to an initial element start, producing a sequence consisting of start, next(start), next(next(start)), etc.
Sq<T>	limit(int n) Return a sequence consisting of the elements of this sequence, truncated to be no longer than n in length.
static <T> Sq<T>	repeat(int n, T v) Return a finite sequence consisting of n copies of the given element v.
Sq<T>	tail() Return the tail of this sequence.
Sq<T>	takeWhile(Predicate<T> p) Return a sequence consisting of the longest prefix of this sequence composed of elements satisfying the predicate p.

Method Detail

empty

static <T> Sq<T> empty()

Return an empty sequence.

Type Parameters:

T - the type of the sequence's elements

Returns:

a finite, empty sequence

constant

static <T> Sq<T> constant(T v)

Return an infinite sequence consisting of a single element repeated infintely.

Type Parameters:

T - the type of the sequence's elements

Parameters:

v - the element to be repeated in the sequence

Returns:

an infinite sequence of the given element

repeat

static <T> Sq<T> repeat(int n,
                        T v)

Return a finite sequence consisting of n copies of the given element v.

Type Parameters:

T - the type of the sequence's elements

Parameters:

n - the length of the resulting sequence

v - the element to be repeated in the sequence

Returns:

a finite sequence

Throws:

IllegalArgumentException - if n is negative

iterate

static <T> Sq<T> iterate(T start,
                         UnaryOperator<T> next)

Returns an infinite sequence produced by iterative application of a function next to an initial element start, producing a sequence consisting of start, next(start), next(next(start)), etc. The first element in the sequence will be the provided start. For n > 0, the element at position n, will be the result of applying the function next to the element at position n - 1.

Type Parameters:

T - the type of the sequence's elements

Parameters:

start - the initial element

next - a function to be applied to the previous element to produce the next element

Returns:

an infinite sequence

isEmpty

boolean isEmpty()

Return true if this sequence contains no elements.

Returns:

true if this sequence contains no elements

head

T head()

Return the head (first element) of this sequence.

Returns:

the head of this sequence

Throws:

NoSuchElementException - if this sequence is empty

tail

Sq<T> tail()

Return the tail of this sequence.

Returns:

the tail of this sequence

Throws:

NoSuchElementException - if this sequence is empty

limit

Sq<T> limit(int n)

Return a sequence consisting of the elements of this sequence, truncated to be no longer than n in length.

Parameters:

n - the number of elements the sequence should be limited to

Returns:

the new sequence

Throws:

IllegalArgumentException - if n is negative

concat

Sq<T> concat(Sq<T> that)

Return a sequence consisting of all the elements of this sequence, followed by all the elements of the given sequence that.

Parameters:

that - the sequence to concatenate at the end of this one

Returns:

the concatenation of this and that sequence

takeWhile

Sq<T> takeWhile(Predicate<T> p)

Return a sequence consisting of the longest prefix of this sequence composed of elements satisfying the predicate p.

Parameters:

p - the predicate

Returns:

a prefix of this sequence

dropWhile

Sq<T> dropWhile(Predicate<T> p)

Return a sequence consisting of the elements of this sequence except all the leading ones satisfying predicate p.

Parameters:

p - the predicate used to filter the prefix

Returns:

a suffix of this sequence

findFirst

default T findFirst(Predicate<T> p)

Return the first element of this sequence satisfying predicate p.

Parameters:

p - the predicate that the returned element must satisfy

Returns:

the first element satisfying the predicate

Throws:

NoSuchElementException - if no element of this sequence satisfies the predicate