org.simmetrics.builders.StringMetricBuilder Maven / Gradle / Ivy
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* #%L
* Simmetrics Core
* %%
* Copyright (C) 2014 - 2015 Simmetrics Authors
* %%
* 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.
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*/
package org.simmetrics.builders;
import static com.google.common.base.Preconditions.checkNotNull;
import static org.simmetrics.metrics.StringMetrics.create;
import static org.simmetrics.metrics.StringMetrics.createForListMetric;
import static org.simmetrics.metrics.StringMetrics.createForMultisetMetric;
import static org.simmetrics.metrics.StringMetrics.createForSetMetric;
import java.util.ArrayList;
import java.util.Collection;
import java.util.List;
import java.util.Set;
import java.util.concurrent.Callable;
import java.util.concurrent.ExecutionException;
import org.simmetrics.ListMetric;
import org.simmetrics.Metric;
import org.simmetrics.MultisetMetric;
import org.simmetrics.SetMetric;
import org.simmetrics.StringMetric;
import org.simmetrics.simplifiers.Simplifier;
import org.simmetrics.simplifiers.Simplifiers;
import org.simmetrics.tokenizers.Tokenizer;
import org.simmetrics.tokenizers.Tokenizers;
import com.google.common.base.Function;
import com.google.common.base.Predicate;
import com.google.common.cache.Cache;
import com.google.common.collect.Multiset;
/**
* Convenience tool to build string metrics. Any class implementing
* {@link StringMetric}, {@link ListMetric}, {@link SetMetric} or
* {@link MultisetMetric} can be used to build a string metric. Supports the
* addition of simplification, tokenization, token-filtering,
* token-transformation and caching to a metric.
*
* For usage examples see the simmetrics-example module.
*/
public final class StringMetricBuilder {
private StringMetricBuilder() {
// Utility class
}
/**
* Starts building a metric with a string metric.
*
* @param metric
* the metric to use as a base
* @return a builder for fluent chaining
*/
public static StringMetricInitialSimplifierStep with(StringMetric metric) {
return new CompositeStringMetricBuilder(metric);
}
/**
* Starts building a metric with a list metric.
*
* @param metric
* the metric to use as a base
* @return a builder for fluent chaining
*/
public static CollectionMetricInitialSimplifierStep> with(
ListMetric metric) {
return new CompositeListMetricBuilder(metric);
}
/**
* Starts building a metric with a set metric.
*
* @param metric
* the metric to use as a base
* @return a builder for fluent chaining
*/
public static CollectionMetricInitialSimplifierStep> with(
SetMetric metric) {
return new CompositeSetMetricBuilder(metric);
}
/**
* Starts building a metric with a multiset metric.
*
* @param metric
* the metric to use as a base
* @return a builder for fluent chaining
*/
public static CollectionMetricInitialSimplifierStep> with(
MultisetMetric metric) {
return new CompositeMultisetMetricBuilder(metric);
}
@SuppressWarnings("javadoc")
public interface BuildStep {
/**
* Builds a metric with the given steps.
*
* @return a metric
*/
StringMetric build();
}
@SuppressWarnings("javadoc")
public interface StringMetricInitialSimplifierStep extends BuildStep {
/**
* Adds a simplifier to the metric.
*
* @param simplifier
* a simplifier to add
* @return this for fluent chaining
*/
StringMetricSimplifierStep simplify(Simplifier simplifier);
/**
* Builds a metric with the given simplifier.
*
* @return a metric
*/
@Override
StringMetric build();
}
@SuppressWarnings("javadoc")
public interface StringMetricSimplifierStep extends
StringMetricInitialSimplifierStep {
/**
* Adds a simplifier to the metric.
*
* @param simplifier
* a simplifier to add
* @return this for fluent chaining
*/
@Override
StringMetricSimplifierStep simplify(Simplifier simplifier);
/**
* Sets a cache for simplification chain. The cache will store the
* result of all previous simplification steps.
*
* @param cache
* a cache to add
* @return this for fluent chaining
*/
BuildStep cacheStrings(Cache cache);
/**
* Builds a metric with the given simplifier.
*
* @return a metric
*/
@Override
StringMetric build();
}
@SuppressWarnings("javadoc")
public interface CollectionMetricInitialSimplifierStep> {
/**
* Adds a simplifier to the metric.
*
* @param simplifier
* a simplifier to add
* @return this for fluent chaining
*/
CollectionMetricSimplifierStep simplify(Simplifier simplifier);
/**
* Adds a tokenization step to the metric.
*
* @param tokenizer
* a tokenizer to add
* @return this for fluent chaining
*/
CollectionMetricTokenizerStep tokenize(Tokenizer tokenizer);
}
@SuppressWarnings("javadoc")
public interface CollectionMetricSimplifierStep>
extends CollectionMetricInitialSimplifierStep {
/**
* Adds a simplifier to the metric.
*
* @param simplifier
* a simplifier to add
* @return this for fluent chaining
*/
@Override
CollectionMetricSimplifierStep simplify(Simplifier simplifier);
/**
* Sets a cache for simplification chain. The cache will store the
* result of all previous simplification steps.
*
* @param cache
* a cache to add
* @return this for fluent chaining
*/
CollectionMetricInitialTokenizerStep cacheStrings(
Cache cache);
/**
* Adds a tokenization step to the metric.
*
* @param tokenizer
* a tokenizer to add
* @return this for fluent chaining
*/
@Override
CollectionMetricTokenizerStep tokenize(Tokenizer tokenizer);
}
@SuppressWarnings("javadoc")
public interface CollectionMetricInitialTokenizerStep> {
/**
* Adds a tokenization step to the metric.
*
* @param tokenizer
* a tokenizer to add
* @return a builder for fluent chaining
*/
CollectionMetricTokenizerStep tokenize(Tokenizer tokenizer);
}
@SuppressWarnings("javadoc")
public interface CollectionMetricTokenizerStep>
extends BuildStep, CollectionMetricInitialTokenizerStep {
/**
* Adds a tokenization step to the metric.
*
* @param tokenizer
* a tokenizer to add
* @return a builder for fluent chaining
*/
@Override
CollectionMetricTokenizerStep tokenize(Tokenizer tokenizer);
/**
* Adds a filter step to the metric. All tokens that match the predicate
* are kept.
*
* @param predicate
* a predicate for tokens to keep
* @return this for fluent chaining
*/
CollectionMetricTokenizerStep filter(Predicate predicate);
/**
* Adds a transform step to the metric. All tokens are transformed by
* the function. The function may not return null.
*
* @param function
* a function to transform tokens
* @return this for fluent chaining
*/
CollectionMetricTokenizerStep transform(
Function function);
/**
* Sets a cache for tokenization chain. The cache will store the result
* of all previous tokenization steps.
*
* @param cache
* a cache to add
* @return this for fluent chaining
*
*/
BuildStep cacheTokens(Cache cache);
/**
* Builds a string metric that will use the given simplification,
* tokenization and filtering steps.
*
* @return a string metric.
*/
@Override
StringMetric build();
}
private static final class CompositeStringMetricBuilder implements
StringMetricSimplifierStep {
private final Metric metric;
private final List simplifiers = new ArrayList<>();
CompositeStringMetricBuilder(Metric metric) {
checkNotNull(metric);
this.metric = metric;
}
@Override
public StringMetric build() {
if (simplifiers.isEmpty()) {
return create(metric);
}
return create(metric, chainSimplifiers());
}
private Simplifier chainSimplifiers() {
final Simplifier simplifier = Simplifiers.chain(simplifiers);
simplifiers.clear();
return simplifier;
}
@Override
public BuildStep cacheStrings(Cache cache) {
checkNotNull(cache);
CachingSimplifier cachingSimplifier = new CachingSimplifier(cache,
chainSimplifiers());
this.simplifiers.add(cachingSimplifier);
return this;
}
@Override
public StringMetricSimplifierStep simplify(Simplifier simplifier) {
checkNotNull(simplifier);
this.simplifiers.add(simplifier);
return this;
}
}
private static abstract class CompositeCollectionMetricBuilder>
implements CollectionMetricSimplifierStep,
CollectionMetricTokenizerStep {
private final Metric metric;
private final List simplifiers = new ArrayList<>();
private final List tokenizers = new ArrayList<>();
CompositeCollectionMetricBuilder(Metric metric) {
checkNotNull(metric);
this.metric = metric;
}
@Override
public final StringMetric build() {
Tokenizer tokenizer = chainTokenizers();
if (simplifiers.isEmpty()) {
return build(metric, tokenizer);
}
return build(metric, chainSimplifiers(), tokenizer);
}
abstract StringMetric build(Metric metric, Simplifier simplifier,
Tokenizer tokenizer);
abstract StringMetric build(Metric metric, Tokenizer tokenizer);
@Override
public final BuildStep cacheTokens(Cache cache) {
checkNotNull(cache);
tokenizers.add(createCachingTokenizer(cache, chainTokenizers()));
return this;
}
protected abstract Tokenizer createCachingTokenizer(
Cache cache, Tokenizer tokenizer);
@Override
public final CollectionMetricInitialTokenizerStep cacheStrings(
Cache cache) {
checkNotNull(cache);
CachingSimplifier cachingSimplifier = new CachingSimplifier(cache,
chainSimplifiers());
this.simplifiers.add(cachingSimplifier);
return this;
}
@Override
public final CollectionMetricSimplifierStep simplify(
Simplifier simplifier) {
checkNotNull(simplifier);
simplifiers.add(simplifier);
return this;
}
@Override
public final CollectionMetricTokenizerStep tokenize(
Tokenizer tokenizer) {
checkNotNull(tokenizer);
tokenizers.add(tokenizer);
return this;
}
@Override
public final CollectionMetricTokenizerStep filter(
Predicate predicate) {
checkNotNull(predicate);
final Tokenizer filter = Tokenizers.filter(chainTokenizers(),
predicate);
tokenizers.add(filter);
return this;
}
@Override
public final CollectionMetricTokenizerStep transform(
Function function) {
checkNotNull(function);
final Tokenizer transform = Tokenizers.transform(chainTokenizers(),
function);
tokenizers.add(transform);
return this;
}
private Tokenizer chainTokenizers() {
final Tokenizer tokenizer = Tokenizers.chain(tokenizers);
tokenizers.clear();
return tokenizer;
}
private Simplifier chainSimplifiers() {
final Simplifier simplifier = Simplifiers.chain(simplifiers);
simplifiers.clear();
return simplifier;
}
}
private static final class CompositeListMetricBuilder extends
CompositeCollectionMetricBuilder> {
CompositeListMetricBuilder(Metric> metric) {
super(metric);
}
@Override
StringMetric build(Metric> metric, Simplifier simplifier,
Tokenizer tokenizer) {
return createForListMetric(metric, simplifier, tokenizer);
}
@Override
StringMetric build(Metric> metric, Tokenizer tokenizer) {
return createForListMetric(metric, tokenizer);
}
@Override
protected Tokenizer createCachingTokenizer(
Cache> cache, Tokenizer tokenizer) {
return new CachingListTokenizer(cache, tokenizer);
}
}
private static final class CompositeSetMetricBuilder extends
CompositeCollectionMetricBuilder> {
CompositeSetMetricBuilder(Metric> metric) {
super(metric);
}
@Override
StringMetric build(Metric> metric, Simplifier simplifier,
Tokenizer tokenizer) {
return createForSetMetric(metric, simplifier, tokenizer);
}
@Override
StringMetric build(Metric> metric, Tokenizer tokenizer) {
return createForSetMetric(metric, tokenizer);
}
@Override
protected Tokenizer createCachingTokenizer(
Cache> cache, Tokenizer tokenizer) {
return new CachingSetTokenizer(cache, tokenizer);
}
}
private static final class CompositeMultisetMetricBuilder extends
CompositeCollectionMetricBuilder> {
CompositeMultisetMetricBuilder(Metric> metric) {
super(metric);
}
@Override
StringMetric build(Metric> metric,
Simplifier simplifier, Tokenizer tokenizer) {
return createForMultisetMetric(metric, simplifier, tokenizer);
}
@Override
StringMetric build(Metric> metric, Tokenizer tokenizer) {
return createForMultisetMetric(metric, tokenizer);
}
@Override
protected Tokenizer createCachingTokenizer(
Cache> cache, Tokenizer tokenizer) {
return new CachingMultisetTokenizer(cache, tokenizer);
}
}
static final class CachingSimplifier implements Simplifier {
private final Cache cache;
final Simplifier simplifier;
CachingSimplifier(Cache cache, Simplifier simplifier) {
this.cache = cache;
this.simplifier = simplifier;
}
@Override
public String simplify(final String input) {
try {
return cache.get(input, new Callable() {
@Override
public String call() throws Exception {
return simplifier.simplify(input);
}
});
} catch (ExecutionException e) {
// Can't happen. Simplifier may not throw checked exceptions
throw new IllegalStateException(e);
}
}
@Override
public String toString() {
return "CachingSimplifier [" + simplifier + "]";
}
}
static final class CachingMultisetTokenizer implements Tokenizer {
private final Cache> cache;
final Tokenizer tokenizer;
CachingMultisetTokenizer(Cache> cache,
Tokenizer tokenizer) {
this.cache = cache;
this.tokenizer = tokenizer;
}
@Override
public List tokenizeToList(final String input) {
throw new UnsupportedOperationException();
}
@Override
public Set tokenizeToSet(final String input) {
throw new UnsupportedOperationException();
}
@Override
public Multiset tokenizeToMultiset(final String input) {
try {
return cache.get(input, new Callable>() {
@Override
public Multiset call() {
return tokenizer.tokenizeToMultiset(input);
}
});
} catch (ExecutionException e) {
// Can't happen. Tokenizer may not throw checked exceptions
throw new IllegalStateException(e);
}
}
@Override
public String toString() {
return "CachingMultisetTokenizer [" + cache + ", " + tokenizer
+ "]";
}
}
static final class CachingSetTokenizer implements Tokenizer {
private final Cache> cache;
final Tokenizer tokenizer;
CachingSetTokenizer(Cache> cache,
Tokenizer tokenizer) {
this.cache = cache;
this.tokenizer = tokenizer;
}
@Override
public List tokenizeToList(final String input) {
throw new UnsupportedOperationException();
}
@Override
public Set tokenizeToSet(final String input) {
try {
return cache.get(input, new Callable>() {
@Override
public Set call() {
return tokenizer.tokenizeToSet(input);
}
});
} catch (ExecutionException e) {
// Can't happen. Tokenizer may not throw checked exceptions
throw new IllegalStateException(e);
}
}
@Override
public Multiset tokenizeToMultiset(final String input) {
throw new UnsupportedOperationException();
}
@Override
public String toString() {
return "CachingSetTokenizer [" + cache + ", " + tokenizer + "]";
}
}
static final class CachingListTokenizer implements Tokenizer {
private final Cache> cache;
final Tokenizer tokenizer;
CachingListTokenizer(Cache> cache,
Tokenizer tokenizer) {
this.cache = cache;
this.tokenizer = tokenizer;
}
@Override
public List tokenizeToList(final String input) {
try {
return cache.get(input, new Callable>() {
@Override
public List call() {
return tokenizer.tokenizeToList(input);
}
});
} catch (ExecutionException e) {
// Can't happen. Tokenizer may not throw checked exceptions
throw new IllegalStateException(e);
}
}
@Override
public Set tokenizeToSet(final String input) {
throw new UnsupportedOperationException();
}
@Override
public Multiset tokenizeToMultiset(final String input) {
throw new UnsupportedOperationException();
}
@Override
public String toString() {
return "CachingListTokenizer [" + cache + ", " + tokenizer + "]";
}
}
}