/* * 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.utility.internal; import java.math.BigDecimal; import java.math.BigInteger; import java.util.Collection; import java.util.Comparator; import java.util.Iterator; import java.util.List; import java.util.Set; import com.gs.collections.api.RichIterable; import com.gs.collections.api.block.HashingStrategy; import com.gs.collections.api.block.function.Function; import com.gs.collections.api.block.function.Function0; import com.gs.collections.api.block.function.Function2; import com.gs.collections.api.block.function.Function3; import com.gs.collections.api.block.function.primitive.BooleanFunction; import com.gs.collections.api.block.function.primitive.ByteFunction; import com.gs.collections.api.block.function.primitive.CharFunction; import com.gs.collections.api.block.function.primitive.DoubleFunction; import com.gs.collections.api.block.function.primitive.DoubleObjectToDoubleFunction; import com.gs.collections.api.block.function.primitive.FloatFunction; import com.gs.collections.api.block.function.primitive.FloatObjectToFloatFunction; import com.gs.collections.api.block.function.primitive.IntFunction; import com.gs.collections.api.block.function.primitive.IntObjectToIntFunction; import com.gs.collections.api.block.function.primitive.LongFunction; import com.gs.collections.api.block.function.primitive.LongObjectToLongFunction; import com.gs.collections.api.block.function.primitive.ShortFunction; import com.gs.collections.api.block.predicate.Predicate; import com.gs.collections.api.block.predicate.Predicate2; import com.gs.collections.api.block.procedure.Procedure; import com.gs.collections.api.block.procedure.Procedure2; import com.gs.collections.api.block.procedure.primitive.ObjectIntProcedure; import com.gs.collections.api.collection.MutableCollection; import com.gs.collections.api.collection.primitive.MutableBooleanCollection; import com.gs.collections.api.collection.primitive.MutableByteCollection; import com.gs.collections.api.collection.primitive.MutableCharCollection; import com.gs.collections.api.collection.primitive.MutableDoubleCollection; import com.gs.collections.api.collection.primitive.MutableFloatCollection; import com.gs.collections.api.collection.primitive.MutableIntCollection; import com.gs.collections.api.collection.primitive.MutableLongCollection; import com.gs.collections.api.collection.primitive.MutableShortCollection; import com.gs.collections.api.list.MutableList; import com.gs.collections.api.map.MutableMap; import com.gs.collections.api.multimap.ImmutableMultimap; import com.gs.collections.api.multimap.MutableMultimap; import com.gs.collections.api.partition.PartitionMutableCollection; import com.gs.collections.api.partition.list.PartitionMutableList; import com.gs.collections.api.tuple.Pair; import com.gs.collections.api.tuple.Twin; import com.gs.collections.impl.block.factory.Functions0; import com.gs.collections.impl.block.factory.HashingStrategies; import com.gs.collections.impl.block.procedure.MutatingAggregationProcedure; import com.gs.collections.impl.block.procedure.NonMutatingAggregationProcedure; import com.gs.collections.impl.factory.Lists; import com.gs.collections.impl.list.mutable.FastList; import com.gs.collections.impl.list.mutable.primitive.BooleanArrayList; import com.gs.collections.impl.list.mutable.primitive.ByteArrayList; import com.gs.collections.impl.list.mutable.primitive.CharArrayList; import com.gs.collections.impl.list.mutable.primitive.DoubleArrayList; import com.gs.collections.impl.list.mutable.primitive.FloatArrayList; import com.gs.collections.impl.list.mutable.primitive.IntArrayList; import com.gs.collections.impl.list.mutable.primitive.LongArrayList; import com.gs.collections.impl.list.mutable.primitive.ShortArrayList; import com.gs.collections.impl.map.mutable.UnifiedMap; import com.gs.collections.impl.multimap.list.FastListMultimap; import com.gs.collections.impl.partition.list.PartitionFastList; import com.gs.collections.impl.set.mutable.UnifiedSet; import com.gs.collections.impl.set.strategy.mutable.UnifiedSetWithHashingStrategy; import com.gs.collections.impl.tuple.Tuples; import com.gs.collections.impl.utility.Iterate; /** * The IteratorIterate class implementations of the various iteration patterns for use with java.util.Iterator. */ public final class IteratorIterate { private IteratorIterate() { throw new AssertionError("Suppress default constructor for noninstantiability"); } /** * @see Iterate#selectAndRejectWith(Iterable, Predicate2, Object) */ public static <T, P> Twin<MutableList<T>> selectAndRejectWith( Iterator<T> iterator, Predicate2<? super T, ? super P> predicate, P parameter) { MutableList<T> positiveResult = Lists.mutable.empty(); MutableList<T> negativeResult = Lists.mutable.empty(); while (iterator.hasNext()) { T item = iterator.next(); (predicate.accept(item, parameter) ? positiveResult : negativeResult).add(item); } return Tuples.twin(positiveResult, negativeResult); } /** * @see Iterate#partition(Iterable, Predicate) */ public static <T> PartitionMutableList<T> partition(Iterator<T> iterator, Predicate<? super T> predicate) { PartitionMutableList<T> result = new PartitionFastList<T>(); MutableList<T> selected = result.getSelected(); MutableList<T> rejected = result.getRejected(); while (iterator.hasNext()) { T each = iterator.next(); MutableList<T> bucket = predicate.accept(each) ? selected : rejected; bucket.add(each); } return result; } /** * @see Iterate#partitionWith(Iterable, Predicate2, Object) * @since 5.0 */ public static <T, P> PartitionMutableList<T> partitionWith( Iterator<T> iterator, Predicate2<? super T, ? super P> predicate, P parameter) { PartitionMutableList<T> result = new PartitionFastList<T>(); MutableList<T> selected = result.getSelected(); MutableList<T> rejected = result.getRejected(); while (iterator.hasNext()) { T each = iterator.next(); MutableList<T> bucket = predicate.accept(each, parameter) ? selected : rejected; bucket.add(each); } return result; } public static <T, R extends PartitionMutableCollection<T>> R partitionWhile(Iterator<T> iterator, Predicate<? super T> predicate, R target) { MutableCollection<T> selected = target.getSelected(); MutableCollection<T> rejected = target.getRejected(); boolean partitionFound = false; while (iterator.hasNext() && !partitionFound) { T next = iterator.next(); if (predicate.accept(next)) { selected.add(next); } else { rejected.add(next); partitionFound = true; } } while (iterator.hasNext()) { rejected.add(iterator.next()); } return target; } public static <T, R extends MutableCollection<T>> R takeWhile(Iterator<T> iterator, Predicate<? super T> predicate, R target) { while (iterator.hasNext()) { T next = iterator.next(); if (predicate.accept(next)) { target.add(next); } else { return target; } } return target; } public static <T, R extends MutableCollection<T>> R dropWhile(Iterator<T> iterator, Predicate<? super T> predicate, R target) { boolean partitionFound = false; while (iterator.hasNext() && !partitionFound) { T next = iterator.next(); if (!predicate.accept(next)) { target.add(next); partitionFound = true; } } while (iterator.hasNext()) { target.add(iterator.next()); } return target; } /** * @see Iterate#count(Iterable, Predicate) */ public static <T> int count(Iterator<T> iterator, Predicate<? super T> predicate) { int count = 0; while (iterator.hasNext()) { if (predicate.accept(iterator.next())) { count++; } } return count; } /** * @see Iterate#countWith(Iterable, Predicate2, Object) */ public static <T, P> int countWith( Iterator<T> iterator, Predicate2<? super T, ? super P> predicate, P parameter) { int count = 0; while (iterator.hasNext()) { if (predicate.accept(iterator.next(), parameter)) { count++; } } return count; } /** * @see Iterate#select(Iterable, Predicate, Collection) */ public static <T, R extends Collection<T>> R select( Iterator<T> iterator, Predicate<? super T> predicate, R targetCollection) { while (iterator.hasNext()) { T item = iterator.next(); if (predicate.accept(item)) { targetCollection.add(item); } } return targetCollection; } /** * @see Iterate#selectWith(Iterable, Predicate2, Object, Collection) */ public static <T, P, R extends Collection<T>> R selectWith( Iterator<T> iterator, Predicate2<? super T, ? super P> predicate, P injectedValue, R targetCollection) { while (iterator.hasNext()) { T item = iterator.next(); if (predicate.accept(item, injectedValue)) { targetCollection.add(item); } } return targetCollection; } /** * @see Iterate#selectInstancesOf(Iterable, Class) */ public static <T, R extends Collection<T>> R selectInstancesOf( Iterator<?> iterator, Class<T> clazz, R targetCollection) { while (iterator.hasNext()) { Object item = iterator.next(); if (clazz.isInstance(item)) { targetCollection.add((T) item); } } return targetCollection; } /** * @see Iterate#selectWith(Iterable, Predicate2, Object, Collection) */ public static <T, V, R extends Collection<V>> R collectIf( Iterator<T> iterator, Predicate<? super T> predicate, Function<? super T, ? extends V> function, R targetCollection) { while (iterator.hasNext()) { T item = iterator.next(); if (predicate.accept(item)) { targetCollection.add(function.valueOf(item)); } } return targetCollection; } /** * @see Iterate#reject(Iterable, Predicate, Collection) */ public static <T, R extends Collection<T>> R reject( Iterator<T> iterator, Predicate<? super T> predicate, R targetCollection) { while (iterator.hasNext()) { T item = iterator.next(); if (!predicate.accept(item)) { targetCollection.add(item); } } return targetCollection; } /** * @see Iterate#rejectWith(Iterable, Predicate2, Object, Collection) */ public static <T, P, R extends Collection<T>> R rejectWith( Iterator<T> iterator, Predicate2<? super T, ? super P> predicate, P parameter, R targetCollection) { while (iterator.hasNext()) { T item = iterator.next(); if (!predicate.accept(item, parameter)) { targetCollection.add(item); } } return targetCollection; } /** * @see Iterate#collect(Iterable, Function, Collection) */ public static <T, V, R extends Collection<V>> R collect( Iterator<T> iterator, Function<? super T, ? extends V> function, R targetCollection) { while (iterator.hasNext()) { targetCollection.add(function.valueOf(iterator.next())); } return targetCollection; } /** * @see Iterate#collectBoolean(Iterable, BooleanFunction) */ public static <T> MutableBooleanCollection collectBoolean( Iterator<T> iterator, BooleanFunction<? super T> booleanFunction) { MutableBooleanCollection result = new BooleanArrayList(); while (iterator.hasNext()) { result.add(booleanFunction.booleanValueOf(iterator.next())); } return result; } /** * @see Iterate#collectBoolean(Iterable, BooleanFunction, MutableBooleanCollection) */ public static <T, R extends MutableBooleanCollection> R collectBoolean( Iterator<T> iterator, BooleanFunction<? super T> booleanFunction, R target) { while (iterator.hasNext()) { target.add(booleanFunction.booleanValueOf(iterator.next())); } return target; } /** * @see Iterate#collectByte(Iterable, ByteFunction) */ public static <T> MutableByteCollection collectByte( Iterator<T> iterator, ByteFunction<? super T> byteFunction) { MutableByteCollection result = new ByteArrayList(); while (iterator.hasNext()) { result.add(byteFunction.byteValueOf(iterator.next())); } return result; } /** * @see Iterate#collectByte(Iterable, ByteFunction, * MutableByteCollection) */ public static <T, R extends MutableByteCollection> R collectByte( Iterator<T> iterator, ByteFunction<? super T> byteFunction, R target) { while (iterator.hasNext()) { target.add(byteFunction.byteValueOf(iterator.next())); } return target; } /** * @see Iterate#collectChar(Iterable, CharFunction) */ public static <T> MutableCharCollection collectChar( Iterator<T> iterator, CharFunction<? super T> charFunction) { MutableCharCollection result = new CharArrayList(); while (iterator.hasNext()) { result.add(charFunction.charValueOf(iterator.next())); } return result; } /** * @see Iterate#collectChar(Iterable, CharFunction, * MutableCharCollection) */ public static <T, R extends MutableCharCollection> R collectChar( Iterator<T> iterator, CharFunction<? super T> charFunction, R target) { while (iterator.hasNext()) { target.add(charFunction.charValueOf(iterator.next())); } return target; } /** * @see Iterate#collectDouble(Iterable, DoubleFunction) */ public static <T> MutableDoubleCollection collectDouble( Iterator<T> iterator, DoubleFunction<? super T> doubleFunction) { MutableDoubleCollection result = new DoubleArrayList(); while (iterator.hasNext()) { result.add(doubleFunction.doubleValueOf(iterator.next())); } return result; } /** * @see Iterate#collectDouble(Iterable, DoubleFunction, * MutableDoubleCollection) */ public static <T, R extends MutableDoubleCollection> R collectDouble( Iterator<T> iterator, DoubleFunction<? super T> doubleFunction, R target) { while (iterator.hasNext()) { target.add(doubleFunction.doubleValueOf(iterator.next())); } return target; } /** * @see Iterate#collectFloat(Iterable, FloatFunction) */ public static <T> MutableFloatCollection collectFloat( Iterator<T> iterator, FloatFunction<? super T> floatFunction) { MutableFloatCollection result = new FloatArrayList(); while (iterator.hasNext()) { result.add(floatFunction.floatValueOf(iterator.next())); } return result; } /** * @see Iterate#collectFloat(Iterable, FloatFunction, * MutableFloatCollection) */ public static <T, R extends MutableFloatCollection> R collectFloat( Iterator<T> iterator, FloatFunction<? super T> floatFunction, R target) { while (iterator.hasNext()) { target.add(floatFunction.floatValueOf(iterator.next())); } return target; } /** * @see Iterate#collectInt(Iterable, IntFunction) */ public static <T> MutableIntCollection collectInt( Iterator<T> iterator, IntFunction<? super T> intFunction) { MutableIntCollection result = new IntArrayList(); while (iterator.hasNext()) { result.add(intFunction.intValueOf(iterator.next())); } return result; } /** * @see Iterate#collectInt(Iterable, IntFunction, * MutableIntCollection) */ public static <T, R extends MutableIntCollection> R collectInt( Iterator<T> iterator, IntFunction<? super T> intFunction, R target) { while (iterator.hasNext()) { target.add(intFunction.intValueOf(iterator.next())); } return target; } /** * @see Iterate#collectLong(Iterable, LongFunction) */ public static <T> MutableLongCollection collectLong( Iterator<T> iterator, LongFunction<? super T> longFunction) { MutableLongCollection result = new LongArrayList(); while (iterator.hasNext()) { result.add(longFunction.longValueOf(iterator.next())); } return result; } /** * @see Iterate#collectLong(Iterable, LongFunction, * MutableLongCollection) */ public static <T, R extends MutableLongCollection> R collectLong( Iterator<T> iterator, LongFunction<? super T> longFunction, R target) { while (iterator.hasNext()) { target.add(longFunction.longValueOf(iterator.next())); } return target; } /** * @see Iterate#collectShort(Iterable, ShortFunction) */ public static <T> MutableShortCollection collectShort( Iterator<T> iterator, ShortFunction<? super T> shortFunction) { MutableShortCollection result = new ShortArrayList(); while (iterator.hasNext()) { result.add(shortFunction.shortValueOf(iterator.next())); } return result; } /** * @see Iterate#collectShort(Iterable, ShortFunction, * MutableShortCollection) */ public static <T, R extends MutableShortCollection> R collectShort( Iterator<T> iterator, ShortFunction<? super T> shortFunction, R target) { while (iterator.hasNext()) { target.add(shortFunction.shortValueOf(iterator.next())); } return target; } /** * @see Iterate#flatCollect(Iterable, Function, Collection) */ public static <T, V, R extends Collection<V>> R flatCollect( Iterator<T> iterator, Function<? super T, ? extends Iterable<V>> function, R targetCollection) { while (iterator.hasNext()) { Iterate.addAllTo(function.valueOf(iterator.next()), targetCollection); } return targetCollection; } /** * @see Iterate#forEach(Iterable, Procedure) */ public static <T> void forEach(Iterator<T> iterator, Procedure<? super T> procedure) { while (iterator.hasNext()) { procedure.value(iterator.next()); } } /** * @see Iterate#forEachWithIndex(Iterable, ObjectIntProcedure) */ public static <T> void forEachWithIndex(Iterator<T> iterator, ObjectIntProcedure<? super T> objectIntProcedure) { int i = 0; while (iterator.hasNext()) { objectIntProcedure.value(iterator.next(), i++); } } /** * @see Iterate#detect(Iterable, Predicate) */ public static <T> T detect(Iterator<T> iterator, Predicate<? super T> predicate) { while (iterator.hasNext()) { T each = iterator.next(); if (predicate.accept(each)) { return each; } } return null; } /** * @see Iterate#detectWith(Iterable, Predicate2, Object) */ public static <T, P> T detectWith(Iterator<T> iterator, Predicate2<? super T, ? super P> predicate, P parameter) { while (iterator.hasNext()) { T each = iterator.next(); if (predicate.accept(each, parameter)) { return each; } } return null; } /** * @see Iterate#injectInto(Object, Iterable, Function2) */ public static <T, IV> IV injectInto( IV injectValue, Iterator<T> iterator, Function2<? super IV, ? super T, ? extends IV> function) { IV result = injectValue; while (iterator.hasNext()) { result = function.value(result, iterator.next()); } return result; } /** * @see Iterate#injectInto(int, Iterable, IntObjectToIntFunction) */ public static <T> int injectInto( int injectValue, Iterator<T> iterator, IntObjectToIntFunction<? super T> function) { int result = injectValue; while (iterator.hasNext()) { result = function.intValueOf(result, iterator.next()); } return result; } /** * @see Iterate#injectInto(long, Iterable, LongObjectToLongFunction) */ public static <T> long injectInto( long injectValue, Iterator<T> iterator, LongObjectToLongFunction<? super T> function) { long result = injectValue; while (iterator.hasNext()) { result = function.longValueOf(result, iterator.next()); } return result; } /** * @see Iterate#injectInto(double, Iterable, DoubleObjectToDoubleFunction) */ public static <T> double injectInto( double injectValue, Iterator<T> iterator, DoubleObjectToDoubleFunction<? super T> function) { double result = injectValue; while (iterator.hasNext()) { result = function.doubleValueOf(result, iterator.next()); } return result; } /** * @see Iterate#injectInto(float, Iterable, FloatObjectToFloatFunction) */ public static <T> float injectInto( float injectValue, Iterator<T> iterator, FloatObjectToFloatFunction<? super T> function) { float result = injectValue; while (iterator.hasNext()) { result = function.floatValueOf(result, iterator.next()); } return result; } /** * @see Iterate#injectIntoWith(Object, Iterable, Function3, Object) */ public static <T, IV, P> IV injectIntoWith(IV injectValue, Iterator<T> iterator, Function3<? super IV, ? super T, ? super P, ? extends IV> function, P parameter) { IV result = injectValue; while (iterator.hasNext()) { result = function.value(result, iterator.next(), parameter); } return result; } public static <T> boolean shortCircuit( Iterator<T> iterator, Predicate<? super T> predicate, boolean expected, boolean onShortCircuit, boolean atEnd) { while (iterator.hasNext()) { T each = iterator.next(); if (predicate.accept(each) == expected) { return onShortCircuit; } } return atEnd; } public static <T, P> boolean shortCircuitWith( Iterator<T> iterator, Predicate2<? super T, ? super P> predicate2, P parameter, boolean expected, boolean onShortCircuit, boolean atEnd) { while (iterator.hasNext()) { T each = iterator.next(); if (predicate2.accept(each, parameter) == expected) { return onShortCircuit; } } return atEnd; } /** * @see Iterate#anySatisfy(Iterable, Predicate) */ public static <T> boolean anySatisfy(Iterator<T> iterator, Predicate<? super T> predicate) { return IteratorIterate.shortCircuit(iterator, predicate, true, true, false); } /** * @see Iterate#anySatisfyWith(Iterable, Predicate2, Object) */ public static <T, P> boolean anySatisfyWith(Iterator<T> iterator, Predicate2<? super T, ? super P> predicate, P parameter) { return IteratorIterate.shortCircuitWith(iterator, predicate, parameter, true, true, false); } /** * @see Iterate#allSatisfy(Iterable, Predicate) */ public static <T> boolean allSatisfy(Iterator<T> iterator, Predicate<? super T> predicate) { return IteratorIterate.shortCircuit(iterator, predicate, false, false, true); } /** * @see Iterate#allSatisfyWith(Iterable, Predicate2, Object) */ public static <T, P> boolean allSatisfyWith(Iterator<T> iterator, Predicate2<? super T, ? super P> predicate, P parameter) { return IteratorIterate.shortCircuitWith(iterator, predicate, parameter, false, false, true); } /** * @see Iterate#noneSatisfy(Iterable, Predicate) */ public static <T> boolean noneSatisfy(Iterator<T> iterator, Predicate<? super T> predicate) { return IteratorIterate.shortCircuit(iterator, predicate, true, false, true); } /** * @see Iterate#noneSatisfyWith(Iterable, Predicate2, Object) */ public static <T, P> boolean noneSatisfyWith(Iterator<T> iterator, Predicate2<? super T, ? super P> predicate, P parameter) { return IteratorIterate.shortCircuitWith(iterator, predicate, parameter, true, false, true); } /** * @see Iterate#removeIf(Iterable, Predicate) */ public static <T> boolean removeIf(Iterator<T> iterator, Predicate<? super T> predicate) { boolean changed = false; while (iterator.hasNext()) { T each = iterator.next(); if (predicate.accept(each)) { iterator.remove(); changed = true; } } return changed; } /** * @see Iterate#removeIfWith(Iterable, Predicate2, Object) */ public static <T, P> boolean removeIfWith(Iterator<T> iterator, Predicate2<? super T, ? super P> predicate, P parameter) { boolean changed = false; while (iterator.hasNext()) { T each = iterator.next(); if (predicate.accept(each, parameter)) { iterator.remove(); changed = true; } } return changed; } public static <T> boolean removeIf(Iterator<T> iterator, Predicate<? super T> predicate, Procedure<? super T> procedure) { boolean changed = false; while (iterator.hasNext()) { T each = iterator.next(); if (predicate.accept(each)) { procedure.value(each); iterator.remove(); changed = true; } } return changed; } public static <T, P> boolean removeIfWith(Iterator<T> iterator, Predicate2<? super T, ? super P> predicate, P parameter, Procedure<? super T> procedure) { boolean changed = false; while (iterator.hasNext()) { T each = iterator.next(); if (predicate.accept(each, parameter)) { procedure.value(each); iterator.remove(); changed = true; } } return changed; } /** * @see Iterate#detectIndex(Iterable, Predicate) */ public static <T> int detectIndex(Iterator<T> iterator, Predicate<? super T> predicate) { int i = 0; while (iterator.hasNext()) { if (predicate.accept(iterator.next())) { return i; } i++; } return -1; } /** * @see Iterate#detectIndexWith(Iterable, Predicate2, Object) */ public static <T, IV> int detectIndexWith(Iterator<T> iterator, Predicate2<? super T, ? super IV> predicate, IV injectedValue) { int i = 0; while (iterator.hasNext()) { if (predicate.accept(iterator.next(), injectedValue)) { return i; } i++; } return -1; } /** * @see Iterate#forEachWith(Iterable, Procedure2, Object) */ public static <T, P> void forEachWith(Iterator<T> iterator, Procedure2<? super T, ? super P> procedure, P parameter) { while (iterator.hasNext()) { procedure.value(iterator.next(), parameter); } } /** * @see Iterate#collectWith(Iterable, Function2, Object, Collection) */ public static <T, P, A, R extends Collection<A>> R collectWith( Iterator<T> iterator, Function2<? super T, ? super P, ? extends A> function, P parameter, R targetCollection) { while (iterator.hasNext()) { targetCollection.add(function.value(iterator.next(), parameter)); } return targetCollection; } /** * @see Iterate#groupBy(Iterable, Function) */ public static <T, V> ImmutableMultimap<V, T> groupBy( Iterator<T> iterator, Function<? super T, ? extends V> function) { return IteratorIterate.groupBy(iterator, function, new FastListMultimap<V, T>()).toImmutable(); } /** * @see Iterate#groupBy(Iterable, Function, MutableMultimap) */ public static <T, V, R extends MutableMultimap<V, T>> R groupBy( Iterator<T> iterator, Function<? super T, ? extends V> function, R target) { while (iterator.hasNext()) { T item = iterator.next(); target.put(function.valueOf(item), item); } return target; } /** * @see Iterate#groupByEach(Iterable, Function, MutableMultimap) */ public static <T, V, R extends MutableMultimap<V, T>> R groupByEach( Iterator<T> iterator, Function<? super T, ? extends Iterable<V>> function, R target) { while (iterator.hasNext()) { T item = iterator.next(); Iterable<V> iterable = function.valueOf(item); for (V key : iterable) { target.put(key, item); } } return target; } /** * @see Iterate#groupByUniqueKey(Iterable, Function, MutableMap) */ public static <K, T, R extends MutableMap<K, T>> R groupByUniqueKey( Iterator<T> iterator, Function<? super T, ? extends K> function, R target) { while (iterator.hasNext()) { T value = iterator.next(); K key = function.valueOf(value); if (target.put(key, value) != null) { throw new IllegalStateException("Key " + key + " already exists in map!"); } } return target; } /** * @deprecated in 7.0. */ @Deprecated public static <T, R extends List<T>> R distinct( Iterator<T> iterator, R targetCollection) { Set<T> seenSoFar = UnifiedSet.newSet(); while (iterator.hasNext()) { T item = iterator.next(); if (seenSoFar.add(item)) { targetCollection.add(item); } } return targetCollection; } /** * @since 7.0. */ public static <T> MutableList<T> distinct(Iterator<T> iterator) { return IteratorIterate.distinct(iterator, FastList.<T>newList()); } /** * @since 7.0. */ public static <T> MutableList<T> distinct(Iterator<T> iterator, HashingStrategy<? super T> hashingStrategy) { Set<T> seenSoFar = UnifiedSetWithHashingStrategy.newSet(hashingStrategy); FastList<T> result = FastList.newList(); while (iterator.hasNext()) { T item = iterator.next(); if (seenSoFar.add(item)) { result.add(item); } } return result; } /** * @see Iterate#zip(Iterable, Iterable, Collection) */ public static <X, Y, R extends Collection<Pair<X, Y>>> R zip( Iterator<X> xs, Iterator<Y> ys, R target) { while (xs.hasNext() && ys.hasNext()) { target.add(Tuples.pair(xs.next(), ys.next())); } return target; } /** * @see Iterate#zipWithIndex(Iterable, Collection) */ public static <T, R extends Collection<Pair<T, Integer>>> R zipWithIndex(Iterator<T> iterator, R target) { int index = 0; while (iterator.hasNext()) { target.add(Tuples.pair(iterator.next(), index)); index += 1; } return target; } /** * @see Iterate#chunk(Iterable, int) */ public static <T> RichIterable<RichIterable<T>> chunk(Iterator<T> iterator, int size) { if (size <= 0) { throw new IllegalArgumentException("Size for groups must be positive but was: " + size); } MutableList<RichIterable<T>> result = Lists.mutable.empty(); while (iterator.hasNext()) { MutableList<T> batch = Lists.mutable.empty(); for (int i = 0; i < size && iterator.hasNext(); i++) { batch.add(iterator.next()); } result.add(batch); } return result; } /** * @see Iterate#min(Iterable, Comparator) */ public static <T> T min(Iterator<T> iterator, Comparator<? super T> comparator) { T min = iterator.next(); while (iterator.hasNext()) { T next = iterator.next(); if (comparator.compare(next, min) < 0) { min = next; } } return min; } /** * @see Iterate#max(Iterable, Comparator) */ public static <T> T max(Iterator<T> iterator, Comparator<? super T> comparator) { T max = iterator.next(); while (iterator.hasNext()) { T next = iterator.next(); if (comparator.compare(next, max) > 0) { max = next; } } return max; } public static <T> Iterator<T> advanceIteratorTo(Iterator<T> iterator, int from) { for (int i = 0; i < from; i++) { iterator.next(); } return iterator; } public static <T> long sumOfInt(Iterator<T> iterator, IntFunction<? super T> function) { long sum = 0L; while (iterator.hasNext()) { sum += (long) function.intValueOf(iterator.next()); } return sum; } public static <T> long sumOfLong(Iterator<T> iterator, LongFunction<? super T> function) { long sum = 0L; while (iterator.hasNext()) { sum += function.longValueOf(iterator.next()); } return sum; } public static <T> double sumOfFloat(Iterator<T> iterator, FloatFunction<? super T> function) { double sum = 0.0d; double compensation = 0.0d; while (iterator.hasNext()) { double adjustedValue = (double) function.floatValueOf(iterator.next()) - compensation; double nextSum = sum + adjustedValue; compensation = nextSum - sum - adjustedValue; sum = nextSum; } return sum; } public static <T> double sumOfDouble(Iterator<T> iterator, DoubleFunction<? super T> function) { double sum = 0.0d; double compensation = 0.0d; while (iterator.hasNext()) { double adjustedValue = function.doubleValueOf(iterator.next()) - compensation; double nextSum = sum + adjustedValue; compensation = nextSum - sum - adjustedValue; sum = nextSum; } return sum; } public static <T> BigDecimal sumOfBigDecimal(Iterator<T> iterator, Function<? super T, BigDecimal> function) { BigDecimal result = BigDecimal.ZERO; while (iterator.hasNext()) { result = result.add(function.valueOf(iterator.next())); } return result; } public static <T> BigInteger sumOfBigInteger(Iterator<T> iterator, Function<? super T, BigInteger> function) { BigInteger result = BigInteger.ZERO; while (iterator.hasNext()) { result = result.add(function.valueOf(iterator.next())); } return result; } public static <V, T> MutableMap<V, BigDecimal> sumByBigDecimal(Iterator<T> iterator, Function<T, V> groupBy, final Function<? super T, BigDecimal> function) { MutableMap<V, BigDecimal> result = UnifiedMap.newMap(); while (iterator.hasNext()) { final T item = iterator.next(); result.updateValue(groupBy.valueOf(item), Functions0.zeroBigDecimal(), new Function<BigDecimal, BigDecimal>() { public BigDecimal valueOf(BigDecimal original) { return original.add(function.valueOf(item)); } }); } return result; } public static <V, T> MutableMap<V, BigInteger> sumByBigInteger(Iterator<T> iterator, Function<T, V> groupBy, final Function<? super T, BigInteger> function) { MutableMap<V, BigInteger> result = UnifiedMap.newMap(); while (iterator.hasNext()) { final T item = iterator.next(); result.updateValue(groupBy.valueOf(item), Functions0.zeroBigInteger(), new Function<BigInteger, BigInteger>() { public BigInteger valueOf(BigInteger original) { return original.add(function.valueOf(item)); } }); } return result; } public static <T, K, V> MutableMap<K, V> aggregateBy( Iterator<T> iterator, Function<? super T, ? extends K> groupBy, Function0<? extends V> zeroValueFactory, Procedure2<? super V, ? super T> mutatingAggregator) { MutableMap<K, V> map = UnifiedMap.newMap(); IteratorIterate.forEach(iterator, new MutatingAggregationProcedure<T, K, V>(map, groupBy, zeroValueFactory, mutatingAggregator)); return map; } public static <T, K, V> MutableMap<K, V> aggregateBy( Iterator<T> iterator, Function<? super T, ? extends K> groupBy, Function0<? extends V> zeroValueFactory, Function2<? super V, ? super T, ? extends V> nonMutatingAggregator) { MutableMap<K, V> map = UnifiedMap.newMap(); IteratorIterate.forEach(iterator, new NonMutatingAggregationProcedure<T, K, V>(map, groupBy, zeroValueFactory, nonMutatingAggregator)); return map; } public static <T, V extends Comparable<? super V>> T minBy(Iterator<T> iterator, Function<? super T, ? extends V> function) { T min = iterator.next(); V minValue = function.valueOf(min); while (iterator.hasNext()) { T next = iterator.next(); V nextValue = function.valueOf(next); if (nextValue.compareTo(minValue) < 0) { min = next; minValue = nextValue; } } return min; } public static <T, V extends Comparable<? super V>> T maxBy(Iterator<T> iterator, Function<? super T, ? extends V> function) { T max = iterator.next(); V maxValue = function.valueOf(max); while (iterator.hasNext()) { T next = iterator.next(); V nextValue = function.valueOf(next); if (nextValue.compareTo(maxValue) > 0) { max = next; maxValue = nextValue; } } return max; } }