/*
* Copyright 2015 Goldman Sachs.
*
* 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.gs.collections.impl.list;
import java.io.Serializable;
import java.math.BigInteger;
import java.util.Collection;
import java.util.Iterator;
import java.util.List;
import java.util.ListIterator;
import java.util.NoSuchElementException;
import java.util.RandomAccess;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.Executor;
import com.gs.collections.api.LazyIterable;
import com.gs.collections.api.bag.MutableBag;
import com.gs.collections.api.block.function.Function;
import com.gs.collections.api.block.function.Function2;
import com.gs.collections.api.block.function.primitive.DoubleObjectToDoubleFunction;
import com.gs.collections.api.block.function.primitive.IntObjectToIntFunction;
import com.gs.collections.api.block.function.primitive.LongObjectToLongFunction;
import com.gs.collections.api.block.predicate.Predicate;
import com.gs.collections.api.block.procedure.Procedure;
import com.gs.collections.api.block.procedure.Procedure2;
import com.gs.collections.api.block.procedure.primitive.IntIntProcedure;
import com.gs.collections.api.block.procedure.primitive.IntObjectProcedure;
import com.gs.collections.api.block.procedure.primitive.IntProcedure;
import com.gs.collections.api.block.procedure.primitive.ObjectIntProcedure;
import com.gs.collections.api.list.MutableList;
import com.gs.collections.api.set.MutableSet;
import com.gs.collections.impl.bag.mutable.HashBag;
import com.gs.collections.impl.block.procedure.CollectProcedure;
import com.gs.collections.impl.block.procedure.CollectionAddProcedure;
import com.gs.collections.impl.block.procedure.RejectProcedure;
import com.gs.collections.impl.block.procedure.SelectProcedure;
import com.gs.collections.impl.factory.Lists;
import com.gs.collections.impl.lazy.AbstractLazyIterable;
import com.gs.collections.impl.list.mutable.FastList;
import com.gs.collections.impl.list.mutable.MutableListIterator;
import com.gs.collections.impl.set.mutable.UnifiedSet;
/**
* An Interval is a range of integers that may be iterated over using a step value. Interval
* is an OO implementation of a for-loop.
*/
public final class Interval
extends AbstractLazyIterable<Integer>
implements List<Integer>, Serializable, RandomAccess
{
private static final long serialVersionUID = 1L;
private final int from;
private final int to;
private final int step;
private Interval(int from, int to, int step)
{
this.from = from;
this.to = to;
this.step = step;
}
/**
* This static {@code from} method allows Interval to act as a fluent builder for itself.
* It works in conjunction with the instance methods {@link #to(int)} and {@link #by(int)}.
* <p>
* Usage Example:
* <pre>
* Interval interval1 = Interval.from(1).to(5); // results in: 1, 2, 3, 4, 5.
* Interval interval2 = Interval.from(1).to(10).by(2); // results in: 1, 3, 5, 7, 9.
* </pre>
*/
public static Interval from(int newFrom)
{
return Interval.fromToBy(newFrom, newFrom, 1);
}
/**
* This instance {@code to} method allows Interval to act as a fluent builder for itself.
* It works in conjunction with the static method {@link #from(int)} and instance method {@link #by(int)}.
* <p>
* Usage Example:
* <pre>
* Interval interval1 = Interval.from(1).to(5); // results in: 1, 2, 3, 4, 5.
* Interval interval2 = Interval.from(1).to(10).by(2); // results in: 1, 3, 5, 7, 9.
* </pre>
*/
public Interval to(int newTo)
{
return Interval.fromToBy(this.from, newTo, this.step);
}
/**
* This instance {@code by} method allows Interval to act as a fluent builder for itself.
* It works in conjunction with the static method {@link #from(int)} and instance method {@link #to(int)}.
* <p>
* Usage Example:
* <pre>
* Interval interval1 = Interval.from(1).to(5); // results in: 1, 2, 3, 4, 5.
* Interval interval2 = Interval.from(1).to(10).by(2); // results in: 1, 3, 5, 7, 9.
* </pre>
*/
public Interval by(int newStep)
{
return Interval.fromToBy(this.from, this.to, newStep);
}
/**
* Returns an Interval starting at zero.
* <p>
* Usage Example:
* <pre>
* Interval interval1 = Interval.zero().to(5); // results in: 0, 1, 2, 3, 4, 5.
* Interval interval2 = Interval.zero().to(10).by(2); // results in: 0, 2, 4, 6, 8, 10.
* </pre>
*/
public static Interval zero()
{
return Interval.from(0);
}
/**
* Returns an Interval starting from 1 to the specified count value with a step value of 1.
*/
public static Interval oneTo(int count)
{
return Interval.oneToBy(count, 1);
}
/**
* Returns an Interval starting from 1 to the specified count value with a step value of step.
*/
public static Interval oneToBy(int count, int step)
{
if (count < 1)
{
throw new IllegalArgumentException("Only positive ranges allowed using oneToBy");
}
return Interval.fromToBy(1, count, step);
}
/**
* Returns an Interval starting from 0 to the specified count value with a step value of 1.
*/
public static Interval zeroTo(int count)
{
return Interval.zeroToBy(count, 1);
}
/**
* Returns an Interval starting from 0 to the specified count value with a step value of step.
*/
public static Interval zeroToBy(int count, int step)
{
return Interval.fromToBy(0, count, step);
}
/**
* Returns an Interval starting from the value from to the specified value to with a step value of 1.
*/
public static Interval fromTo(int from, int to)
{
if (from <= to)
{
return Interval.fromToBy(from, to, 1);
}
return Interval.fromToBy(from, to, -1);
}
/**
* Returns an Interval representing the even values from the value from to the value to.
*/
public static Interval evensFromTo(int from, int to)
{
if (from % 2 != 0)
{
if (from < to)
{
from++;
}
else
{
from--;
}
}
if (to % 2 != 0)
{
if (to > from)
{
to--;
}
else
{
to++;
}
}
return Interval.fromToBy(from, to, to > from ? 2 : -2);
}
/**
* Returns an Interval representing the odd values from the value from to the value to.
*/
public static Interval oddsFromTo(int from, int to)
{
if (from % 2 == 0)
{
if (from < to)
{
from++;
}
else
{
from--;
}
}
if (to % 2 == 0)
{
if (to > from)
{
to--;
}
else
{
to++;
}
}
return Interval.fromToBy(from, to, to > from ? 2 : -2);
}
/**
* Returns an Set representing the Integer values from the value from to the value to.
*/
public static MutableSet<Integer> toSet(int from, int to)
{
MutableSet<Integer> targetCollection = UnifiedSet.newSet();
Interval.fromTo(from, to).forEach(CollectionAddProcedure.on(targetCollection));
return targetCollection;
}
/**
* Returns a MutableList representing the Integer values from the value from to the value to in reverse.
*/
public static MutableList<Integer> toReverseList(int from, int to)
{
return Interval.fromTo(from, to).reverseThis().toList();
}
/**
* Returns an Integer array with the values inclusively between from and to.
*/
public static Integer[] toArray(int from, int to)
{
return Interval.fromTo(from, to).toArray();
}
public static Integer[] toReverseArray(int from, int to)
{
return Interval.fromTo(from, to).reverseThis().toArray();
}
/**
* Returns an Interval for the range of integers inclusively between from and to with the specified
* stepBy value.
*/
public static Interval fromToBy(int from, int to, int stepBy)
{
if (stepBy == 0)
{
throw new IllegalArgumentException("Cannot use a step by of 0");
}
if (from > to && stepBy > 0 || from < to && stepBy < 0)
{
throw new IllegalArgumentException("Step by is incorrect for the range");
}
return new Interval(from, to, stepBy);
}
/**
* Returns true if the Interval contains all of the specified int values.
*/
public boolean containsAll(int... values)
{
for (int value : values)
{
if (!this.contains(value))
{
return false;
}
}
return true;
}
/**
* Returns true if the Interval contains none of the specified int values.
*/
public boolean containsNone(int... values)
{
for (int value : values)
{
if (this.contains(value))
{
return false;
}
}
return true;
}
@Override
public boolean contains(Object object)
{
return object instanceof Integer && this.contains(((Integer) object).intValue());
}
/**
* Returns true if the Interval contains the specified int value.
*/
public boolean contains(int value)
{
return this.isWithinBoundaries(value) && (value - this.from) % this.step == 0;
}
private boolean isWithinBoundaries(int value)
{
return this.step > 0 && this.from <= value && value <= this.to
|| this.step < 0 && this.to <= value && value <= this.from;
}
/**
* Returns the Number result of calculating factorial for the range.
*/
public Number factorial()
{
this.failIfOutOfFactorialRange();
return this.from == 0 ? Integer.valueOf(1) : this.product();
}
/**
* Returns the Number result of calculating product for the range.
*/
public Number product()
{
return this.bigIntegerProduct();
}
/**
* Returns the BigInteger result of calculating product for the range.
*/
private BigInteger bigIntegerProduct()
{
return this.injectInto(BigInteger.valueOf(1L), new Function2<BigInteger, Integer, BigInteger>()
{
public BigInteger value(BigInteger result, Integer each)
{
return result.multiply(BigInteger.valueOf(each.longValue()));
}
});
}
private void failIfOutOfFactorialRange()
{
if (this.from < 0 || this.step != 1)
{
throw new IllegalStateException("Cannot calculate factorial on negative ranges");
}
}
public void forEachWithIndex(IntIntProcedure procedure)
{
int index = 0;
if (this.goForward())
{
for (int i = this.from; i <= this.to; i += this.step)
{
procedure.value(i, index++);
}
}
else
{
for (int i = this.from; i >= this.to; i += this.step)
{
procedure.value(i, index++);
}
}
}
@Override
public void forEachWithIndex(final ObjectIntProcedure<? super Integer> objectIntProcedure)
{
this.forEachWithIndex(new IntIntProcedure()
{
public void value(int each, int index)
{
objectIntProcedure.value(each, index);
}
});
}
public <P> void forEachWith(IntObjectProcedure<? super P> procedure, P parameter)
{
if (this.goForward())
{
for (int i = this.from; i <= this.to; i += this.step)
{
procedure.value(i, parameter);
}
}
else
{
for (int i = this.from; i >= this.to; i += this.step)
{
procedure.value(i, parameter);
}
}
}
public boolean goForward()
{
return this.from <= this.to && this.step > 0;
}
@Override
public <P> void forEachWith(final Procedure2<? super Integer, ? super P> procedure, P parameter)
{
this.forEachWith(new IntObjectProcedure<P>()
{
public void value(int each, P parameter)
{
procedure.value(each, parameter);
}
}, parameter);
}
public void forEach(IntProcedure procedure)
{
if (this.goForward())
{
for (int i = this.from; i <= this.to; i += this.step)
{
procedure.value(i);
}
}
else
{
for (int i = this.from; i >= this.to; i += this.step)
{
procedure.value(i);
}
}
}
public void each(final Procedure<? super Integer> procedure)
{
this.forEach(new IntProcedure()
{
public void value(int each)
{
procedure.value(each);
}
});
}
/**
* This method executes a void procedure against an executor, passing the current index of the
* interval.
*/
public void forEach(Procedure<? super Integer> procedure, Executor executor)
{
CountDownLatch latch = new CountDownLatch(this.size());
if (this.goForward())
{
// Iterates in forward direction because step value is negative
for (int i = this.from; i <= this.to; i += this.step)
{
this.executeAndCountdown(procedure, executor, latch, i);
}
}
else
{
// Iterates in reverse because step value is negative
for (int i = this.from; i >= this.to; i += this.step)
{
this.executeAndCountdown(procedure, executor, latch, i);
}
}
try
{
latch.await();
}
catch (InterruptedException e)
{
// do nothing here;
}
}
private void executeAndCountdown(
final Procedure<? super Integer> procedure,
Executor executor,
final CountDownLatch latch,
final Integer integer)
{
executor.execute(new Runnable()
{
public void run()
{
try
{
procedure.value(integer);
}
finally
{
latch.countDown();
}
}
});
}
/**
* This method runs a runnable a specified number of times against on the current thread.
*/
public void run(Runnable runnable)
{
if (this.goForward())
{
for (int i = this.from; i <= this.to; i += this.step)
{
runnable.run();
}
}
else
{
for (int i = this.from; i >= this.to; i += this.step)
{
runnable.run();
}
}
}
/**
* This method runs a runnable a specified number of times against an executor. The method is effectively
* asynchronous because it does not wait for all of the runnables to finish.
*/
public void run(Runnable runnable, Executor executor)
{
if (this.goForward())
{
for (int i = this.from; i <= this.to; i += this.step)
{
executor.execute(runnable);
}
}
else
{
for (int i = this.from; i >= this.to; i += this.step)
{
executor.execute(runnable);
}
}
}
@Override
public <R> R injectInto(R injectValue, Function2<? super R, ? super Integer, ? extends R> function)
{
R result = injectValue;
if (this.goForward())
{
for (int i = this.from; i <= this.to; i += this.step)
{
result = function.value(result, i);
}
}
else
{
for (int i = this.from; i >= this.to; i += this.step)
{
result = function.value(result, i);
}
}
return result;
}
@Override
public int injectInto(int injectedValue, IntObjectToIntFunction<? super Integer> function)
{
int result = injectedValue;
if (this.goForward())
{
for (int i = this.from; i <= this.to; i += this.step)
{
result = function.intValueOf(result, i);
}
}
else
{
for (int i = this.from; i >= this.to; i += this.step)
{
result = function.intValueOf(result, i);
}
}
return result;
}
@Override
public long injectInto(long injectedValue, LongObjectToLongFunction<? super Integer> function)
{
long result = injectedValue;
if (this.goForward())
{
for (int i = this.from; i <= this.to; i += this.step)
{
result = function.longValueOf(result, i);
}
}
else
{
for (int i = this.from; i >= this.to; i += this.step)
{
result = function.longValueOf(result, i);
}
}
return result;
}
@Override
public double injectInto(double injectedValue, DoubleObjectToDoubleFunction<? super Integer> function)
{
double result = injectedValue;
if (this.goForward())
{
for (int i = this.from; i <= this.to; i += this.step)
{
result = function.doubleValueOf(result, i);
}
}
else
{
for (int i = this.from; i >= this.to; i += this.step)
{
result = function.doubleValueOf(result, i);
}
}
return result;
}
public void reverseForEach(Procedure<? super Integer> procedure)
{
this.reverseThis().forEach(procedure);
}
public <R> R reverseInjectInto(R injectValue, Function2<R, Integer, R> function)
{
return this.reverseThis().injectInto(injectValue, function);
}
public <R extends Collection<Integer>> R addAllTo(R targetCollection)
{
this.forEach(CollectionAddProcedure.on(targetCollection));
return targetCollection;
}
@Override
public <T, R extends Collection<T>> R collect(
Function<? super Integer, ? extends T> function,
R target)
{
CollectProcedure<Integer, T> procedure = new CollectProcedure<Integer, T>(function, target);
this.forEach(procedure);
return target;
}
@Override
public <R extends Collection<Integer>> R select(Predicate<? super Integer> predicate, R target)
{
SelectProcedure<Integer> procedure = new SelectProcedure<Integer>(predicate, target);
this.forEach(procedure);
return target;
}
@Override
public <R extends Collection<Integer>> R reject(Predicate<? super Integer> predicate, R target)
{
RejectProcedure<Integer> procedure = new RejectProcedure<Integer>(predicate, target);
this.forEach(procedure);
return target;
}
@Override
public boolean equals(Object otherList)
{
if (otherList == this)
{
return true;
}
if (!(otherList instanceof List))
{
return false;
}
List<?> list = (List<?>) otherList;
if (otherList instanceof RandomAccess)
{
if (this.size() != list.size())
{
return false;
}
}
ListIterator<?> listIterator = ((List<?>) otherList).listIterator();
if (this.goForward())
{
for (int i = this.from; i <= this.to && listIterator.hasNext(); i += this.step)
{
Object object = listIterator.next();
if (this.intObjectEqual(i, object))
{
return false;
}
}
}
else
{
for (int i = this.from; i >= this.to && listIterator.hasNext(); i += this.step)
{
Object object = listIterator.next();
if (this.intObjectEqual(i, object))
{
return false;
}
}
}
return !listIterator.hasNext();
}
private boolean intObjectEqual(int i, Object object)
{
return object == null || !(object instanceof Integer) || ((Integer) object).intValue() != i;
}
@Override
public int hashCode()
{
int hashCode = 1;
if (this.goForward())
{
for (int i = this.from; i <= this.to; i += this.step)
{
hashCode = 31 * hashCode + i;
}
}
else
{
for (int i = this.from; i >= this.to; i += this.step)
{
hashCode = 31 * hashCode + i;
}
}
return hashCode;
}
/**
* Returns a new interval with the from and to values reversed and the step value negated.
*/
public Interval reverseThis()
{
return Interval.fromToBy(this.to, this.from, -this.step);
}
/**
* Calculates and returns the size of the interval.
*/
@Override
public int size()
{
return (this.to - this.from) / this.step + 1;
}
@Override
public Integer[] toArray()
{
final Integer[] result = new Integer[this.size()];
this.forEachWithIndex(new ObjectIntProcedure<Integer>()
{
public void value(Integer each, int index)
{
result[index] = each;
}
});
return result;
}
/**
* Converts the interval to an Integer array
*/
public int[] toIntArray()
{
final int[] result = new int[this.size()];
this.forEachWithIndex(new IntIntProcedure()
{
public void value(int each, int index)
{
result[index] = each;
}
});
return result;
}
@Override
public String toString()
{
return "Interval from: " + this.from + " to: " + this.to + " step: " + this.step + " size: " + this.size();
}
public Iterator<Integer> iterator()
{
return new IntegerIterator();
}
private class IntegerIterator implements Iterator<Integer>
{
private int current = Interval.this.from;
public boolean hasNext()
{
if (Interval.this.from <= Interval.this.to)
{
return this.current <= Interval.this.to;
}
return this.current >= Interval.this.to;
}
public Integer next()
{
if (this.hasNext())
{
Integer result = this.current;
this.current += Interval.this.step;
return result;
}
throw new NoSuchElementException();
}
public void remove()
{
throw new UnsupportedOperationException("Cannot remove a value from an Interval");
}
}
@Override
public Integer getFirst()
{
return this.from;
}
@Override
public Integer getLast()
{
return this.locationAfterN(this.size() - 1);
}
public void forEach(Procedure<? super Integer> procedure, int startIndex, int endIndex)
{
this.checkBounds("startIndex", startIndex);
this.checkBounds("endIndex", endIndex);
if (startIndex <= endIndex)
{
for (int i = startIndex; i <= endIndex; i++)
{
procedure.value(this.locationAfterN(i));
}
}
else
{
for (int i = startIndex; i >= endIndex; i--)
{
procedure.value(this.locationAfterN(i));
}
}
}
public void forEachWithIndex(ObjectIntProcedure<? super Integer> objectIntProcedure, int startIndex, int endIndex)
{
this.checkBounds("startIndex", startIndex);
this.checkBounds("endIndex", endIndex);
if (startIndex <= endIndex)
{
for (int i = startIndex; i <= endIndex; i++)
{
objectIntProcedure.value(this.locationAfterN(i), i);
}
}
else
{
for (int i = startIndex; i >= endIndex; i--)
{
objectIntProcedure.value(this.locationAfterN(i), i);
}
}
}
public Integer get(int index)
{
this.checkBounds("index", index);
return this.locationAfterN(index);
}
private void checkBounds(String name, int index)
{
if (index < 0 || index >= this.size())
{
throw new IndexOutOfBoundsException(name + ": " + index + ' ' + this.toString());
}
}
private int locationAfterN(int index)
{
if (index <= 0)
{
return this.from;
}
if (this.step > 0)
{
return (int) Math.min((long) this.from + (long) this.step * (long) index, this.to);
}
return (int) Math.max((long) this.from + (long) this.step * (long) index, this.to);
}
public int indexOf(Object object)
{
if (!(object instanceof Integer))
{
return -1;
}
Integer value = (Integer) object;
if (!this.isWithinBoundaries(value))
{
return -1;
}
int diff = value - this.from;
if (diff % this.step == 0)
{
return diff / this.step;
}
return -1;
}
public int lastIndexOf(Object object)
{
return this.indexOf(object);
}
@Override
public MutableList<Integer> toList()
{
FastList<Integer> list = FastList.newList(this.size());
this.forEach(CollectionAddProcedure.on(list));
return list;
}
@Override
public MutableSet<Integer> toSet()
{
MutableSet<Integer> set = UnifiedSet.newSet(this.size());
this.forEach(CollectionAddProcedure.on(set));
return set;
}
@Override
public MutableBag<Integer> toBag()
{
MutableBag<Integer> bag = HashBag.newBag(this.size());
this.forEach(CollectionAddProcedure.on(bag));
return bag;
}
public boolean add(Integer integer)
{
throw new UnsupportedOperationException("Cannot call add() on " + this.getClass().getSimpleName());
}
public boolean remove(Object o)
{
throw new UnsupportedOperationException("Cannot call remove() on " + this.getClass().getSimpleName());
}
@SuppressWarnings("TypeParameterExtendsFinalClass")
public boolean addAll(Collection<? extends Integer> collection)
{
throw new UnsupportedOperationException("Cannot call addAll() on " + this.getClass().getSimpleName());
}
@SuppressWarnings("TypeParameterExtendsFinalClass")
public boolean addAll(int index, Collection<? extends Integer> collection)
{
throw new UnsupportedOperationException("Cannot call addAll() on " + this.getClass().getSimpleName());
}
public boolean removeAll(Collection<?> collection)
{
throw new UnsupportedOperationException("Cannot call removeAll() on " + this.getClass().getSimpleName());
}
public boolean retainAll(Collection<?> collection)
{
throw new UnsupportedOperationException("Cannot call retainAll() on " + this.getClass().getSimpleName());
}
public void clear()
{
throw new UnsupportedOperationException("Cannot call clear() on " + this.getClass().getSimpleName());
}
public Integer set(int index, Integer element)
{
throw new UnsupportedOperationException("Cannot call set() on " + this.getClass().getSimpleName());
}
public void add(int index, Integer element)
{
throw new UnsupportedOperationException("Cannot call add() on " + this.getClass().getSimpleName());
}
public Integer remove(int index)
{
throw new UnsupportedOperationException("Cannot call remove() on " + this.getClass().getSimpleName());
}
public ListIterator<Integer> listIterator()
{
return new MutableListIterator<Integer>(this, 0);
}
public ListIterator<Integer> listIterator(int index)
{
return new MutableListIterator<Integer>(this, index);
}
public Interval subList(int fromIndex, int toIndex)
{
return Interval.fromToBy(this.get(fromIndex), this.get(toIndex - 1), this.step);
}
@Override
public Interval take(int count)
{
if (count < 0)
{
throw new IllegalArgumentException("Count must be greater than zero, but was: " + count);
}
if (count > 0 && this.notEmpty())
{
return Interval.fromToBy(this.from, this.locationAfterN(count - 1), this.step);
}
return Interval.fromToBy(this.from, this.from, this.step);
}
@Override
public LazyIterable<Integer> drop(int count)
{
if (count < 0)
{
throw new IllegalArgumentException("Count must be greater than zero, but was: " + count);
}
if (count >= this.size())
{
return Lists.immutable.<Integer>of().asLazy();
}
return Interval.fromToBy(this.locationAfterN(count), this.to, this.step);
}
@Override
public LazyIterable<Integer> distinct()
{
return this;
}
}