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/*
* Copyright 2022 Igor Maznitsa
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.igormaznitsa.mistack;
import static com.igormaznitsa.mistack.MiStackPredicates.itemsAll;
import static java.util.Spliterator.ORDERED;
import static java.util.Spliterators.spliteratorUnknownSize;
import java.util.Collection;
import java.util.Iterator;
import java.util.List;
import java.util.Optional;
import java.util.function.Predicate;
import java.util.stream.Collectors;
import java.util.stream.Stream;
import java.util.stream.StreamSupport;
/**
* A multi-context stack. It provides way to make iterations through tag marked elements.
*
* @param value type for the stack
* @param container for values for the stack
* @param type of stack item tags
* @author Igor Maznitsa
* @since 2.0.0
*/
public interface MiStack, T extends MiStackTag>
extends Iterable, AutoCloseable {
/**
* Make predicate to check all tags presented for stack item.
*
* @param tags array of tags, must not contain null or be null
* @param type of stack items.
* @param type of stack item tag.
* @return predicate returns true only if all tags presented for stack item.
* @since 2.0.0
*/
@SafeVarargs
static , T extends MiStackTag> Predicate allTags(final T... tags) {
return allTags(List.of(tags));
}
/**
* Make predicate to check all tags presented for stack item.
*
* @param tags array of tag collections, must not contain null or be null
* @param type of stack items.
* @param type of stack item tag.
* @return predicate returns true only if all tags presented for stack item.
* @since 2.0.0
*/
@SafeVarargs
static , T extends MiStackTag> Predicate allTags(
final Collection... tags) {
var setOfAllTags = Stream.of(tags).flatMap(Collection::stream).collect(Collectors.toSet());
return e -> e.getTags().containsAll(setOfAllTags);
}
/**
* Make predicate to check any tag presented for stack item.
*
* @param tags array of tags, must not contain null or be null
* @param type of stack items.
* @return predicate returns true only if all tags presented for stack item.
* @since 2.0.0
*/
@SafeVarargs
static , T extends MiStackTag> Predicate anyTag(final T... tags) {
return anyTag(List.of(tags));
}
/**
* Make predicate to check any tag presented for stack item.
*
* @param tags array of tag collections, must not contain null or be null
* @param type of stack itemS.
* @return predicate returns true only if all tags presented for stack item.
* @since 2.0.0
*/
@SafeVarargs
static , T extends MiStackTag> Predicate anyTag(
final Collection... tags) {
var setOfTags = Stream.of(tags).flatMap(Collection::stream).collect(Collectors.toSet());
return e -> e.getTags().stream().anyMatch(setOfTags::contains);
}
/**
* Push multiple elements on the stack.
*
* @param items elements to be pushed on the stack, must not contain any null element.
* @return the stack instance
* @throws IllegalStateException thrown if stack already closed.
* @since 2.0.0
*/
@SuppressWarnings("unchecked")
default MiStack push(final I... items) {
for (final I item : items) {
this.push(item);
}
return this;
}
/**
* Push single element on the stack.
*
* @param item element to be pushed on the stack, must not be null.
* @return the stack instance
* @throws IllegalStateException thrown if stack already closed.
* @since 2.0.0
*/
MiStack push(I item);
/**
* Pop the first element from the stack which meet predicate condition.
* The element will be removed from the stack.
*
* @param predicate condition for element search, must not be null
* @return condition for element search, must not be null
* @throws IllegalStateException thrown if stack already closed.
* @since 2.0.0
*/
default Optional pop(final Predicate predicate) {
this.assertNotClosed();
I result = null;
var iterator = this.iterator(predicate, itemsAll());
if (iterator.hasNext()) {
result = iterator.next();
iterator.remove();
}
return Optional.ofNullable(result);
}
/**
* Assert that the stack is not closed.
*
* @throws IllegalStateException thrown if stack already closed.
* @since 2.0.0
*/
default void assertNotClosed() {
if (this.isClosed()) {
throw new IllegalStateException("Stack " + this.getName() + " is already closed");
}
}
/**
* Make iterator for stack elements which meet predicate with possibility to stop
* iteration by predicate.
*
* @param predicate condition for elements, must not be null.
* @param takeWhile condition predicate to take next element if true, if false then iteration
* stopped, must not be null.
* @return created iterator, must not be null.
* @throws IllegalStateException thrown if stack already closed.
* @since 2.0.0
*/
TruncableIterator iterator(Predicate predicate,
Predicate takeWhile);
/**
* Allows to get information that the stack is closed.
*
* @return true if the stack is closed, false otherwise.
* @since 2.0.0
*/
boolean isClosed();
/**
* Get stack name.
*
* @return the stack name, it can't be null
* @since 2.0.0
*/
String getName();
/**
* Peek element on the stack which meet predicate condition.
* The element won't be removed from stack.
*
* @param predicate condition for element search, must not be null
* @param depth how many elements must be skipped during search
* @return found element
* @throws IllegalStateException thrown if stack already closed.
* @since 2.0.0
*/
default Optional peek(final Predicate predicate, long depth) {
this.assertNotClosed();
I result = null;
final Iterator iterator = this.iterator(predicate, itemsAll());
while (iterator.hasNext() && result == null) {
result = iterator.next();
if (predicate.test(result)) {
if (depth > 0L) {
result = null;
depth--;
}
}
}
return Optional.ofNullable(result);
}
/**
* Find and remove element on the stack which meet predicate condition.
*
* @param predicate condition for element search, must not be null
* @param depth how many elements must be skipped during search
* @return removed element
* @throws IllegalStateException thrown if stack already closed.
* @since 2.0.0
*/
default Optional remove(final Predicate predicate, long depth) {
this.assertNotClosed();
I result = null;
final Iterator iterator = this.iterator(predicate, itemsAll());
while (iterator.hasNext() && result == null) {
result = iterator.next();
if (predicate.test(result)) {
if (depth > 0L) {
result = null;
depth--;
} else {
iterator.remove();
}
}
}
return Optional.ofNullable(result);
}
/**
* Remove all elements from the stack.
*
* @throws IllegalStateException thrown if stack already closed.
* @since 1.0.0
*/
void clear();
/**
* Remove all elements from the stack which meet predicate condition.
*
* @param predicate condition for elements, must not be null.
* @throws IllegalStateException thrown if stack already closed.
* @since 2.0.0
*/
default void clear(final Predicate predicate) {
this.assertNotClosed();
var iterator = this.iterator();
while (iterator.hasNext()) {
if (predicate.test(iterator.next())) {
iterator.remove();
}
}
}
/**
* Make iterator for all stack elements.
*
* @return created iterator, must not be null.
* @throws IllegalStateException thrown if stack already closed.
* @since 2.0.0
*/
default TruncableIterator iterator() {
this.assertNotClosed();
return this.iterator(itemsAll());
}
/**
* Make iterator for stack elements which meet predicate.
*
* @param predicate condition for elements, must not be null.
* @return created iterator, must not be null.
* @throws IllegalStateException thrown if stack already closed.
* @since 2.0.0
*/
default TruncableIterator iterator(Predicate predicate) {
this.assertNotClosed();
return this.iterator(predicate, itemsAll());
}
/**
* Make stream of all elements on the stack.
*
* @return stream with all stacked elements in their order on the stack, must not be null.
* @throws IllegalStateException thrown if stack already closed.
* @since 2.0.0
*/
default Stream stream() {
this.assertNotClosed();
return this.stream(itemsAll(), itemsAll());
}
/**
* Get stream of stack items meet predicate.
*
* @param predicate condition for elements, must not be null.
* @param takeWhile predicated to take elements while it is true, must not be null.
* @return created stream of all stacked elements meet predicate in their stack order, must
* not be null.
* @throws IllegalStateException thrown if stack already closed.
* @since 2.0.0
*/
default Stream stream(Predicate predicate,
Predicate takeWhile) {
return StreamSupport.stream(
spliteratorUnknownSize(this.iterator(predicate, takeWhile), ORDERED), false);
}
/**
* Check that there is no any element on the stack for predicate.
*
* @param predicate it allows to select items which should take part in search
* @return true if the stack is empty, false elsewhere
* @throws IllegalStateException thrown if stack already closed.
* @since 2.0.0
*/
default boolean isEmpty(Predicate predicate) {
if (this.isEmpty()) {
return true;
}
boolean foundAny = false;
var iterator = this.iterator();
while (iterator.hasNext() && !foundAny) {
foundAny = predicate.test(iterator.next());
}
return !foundAny;
}
/**
* Check that there is no any element on the stack.
*
* @return true if the stack is empty, false elsewhere
* @throws IllegalStateException thrown if stack already closed.
* @since 1.0.0
*/
boolean isEmpty();
/**
* Find size of stack for elements meet predicate.
*
* @param predicate condition for elements, must not be null
* @return number of found elements on the stack
* @throws IllegalStateException thrown if stack already closed.
* @since 2.0.0
*/
default long size(Predicate predicate) {
this.assertNotClosed();
return this.stream(predicate).count();
}
/**
* Get stream of stack items meet predicate.
*
* @param predicate condition for elements, must not be null.
* @return created stream of all stacked elements meet predicate in their stack order, must
* not be null.
* @throws IllegalStateException thrown if stack already closed.
* @since 2.0.0
*/
default Stream stream(Predicate predicate) {
this.assertNotClosed();
return this.stream(predicate, itemsAll());
}
/**
* Get number of all stack elements.
*
* @return number of all stack elements, 0 for empty stack.
* @throws IllegalStateException thrown if stack already closed.
* @since 1.0.0
*/
long size();
/**
* Close the stack and dispose its internal resources. After call the method.
*
* @throws IllegalStateException thrown if stack already closed.
* @since 1.0.0
*/
@Override
void close();
}
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