org.textmapper.lapg.builder.LiTemplateEnvironment Maven / Gradle / Ivy
/**
* Copyright 2002-2018 Evgeny Gryaznov
*
* 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 org.textmapper.lapg.builder;
import org.textmapper.lapg.api.NamedElement;
import org.textmapper.lapg.api.TemplateEnvironment;
import org.textmapper.lapg.api.TemplateParameter;
import org.textmapper.lapg.api.TemplateParameter.Modifier;
import java.util.*;
public class LiTemplateEnvironment implements TemplateEnvironment {
public static final Comparator TEMPLATE_PARAMETER_COMPARATOR =
Comparator.comparing(NamedElement::getNameText);
private final Map values;
private String nonterminalSuffix;
LiTemplateEnvironment() {
values = new HashMap<>();
}
private LiTemplateEnvironment(Map map) {
values = map;
}
@Override
public Object getValue(TemplateParameter param) {
Object val = values.get(param);
return val != null ? val : param.getDefaultValue();
}
@Override
public TemplateEnvironment extend(TemplateParameter param, Object value) {
Map result;
if (value == null || value.equals(param.getDefaultValue())) {
if (!values.containsKey(param)) {
return this;
}
result = new HashMap<>(values);
result.remove(param);
} else {
if (value.equals(values.get(param))) {
return this;
}
result = new HashMap<>(values);
result.put(param, value);
}
return new LiTemplateEnvironment(result);
}
@Override
public String getNonterminalSuffix() {
if (nonterminalSuffix != null) return nonterminalSuffix;
List params = new ArrayList<>(values.keySet());
Collections.sort(params, TEMPLATE_PARAMETER_COMPARATOR);
StringBuilder sb = new StringBuilder();
for (TemplateParameter param : params) {
param.appendSuffix(sb, values.get(param));
}
return nonterminalSuffix = sb.toString();
}
@Override
public TemplateEnvironment filter(ParameterPredicate predicate) {
TemplateEnvironment env = this;
for (TemplateParameter param : values.keySet()) {
if (!predicate.include(param)) env = env.extend(param, null);
}
return env;
}
@Override
public boolean hasLookahead() {
for (TemplateParameter param : values.keySet()) {
if (param.getModifier() == Modifier.Lookahead) return true;
}
return false;
}
@Override
public boolean equals(Object o) {
if (this == o) return true;
if (o == null || getClass() != o.getClass()) return false;
LiTemplateEnvironment that = (LiTemplateEnvironment) o;
return values.equals(that.values);
}
@Override
public int hashCode() {
return values.hashCode();
}
}