/*******************************************************************************
* Copyright 2017 Capital One Services, LLC and Bitwise, Inc.
* 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 hydrograph.engine.expression.api;
import hydrograph.engine.expression.antlr.ExpressionEditorBaseVisitor;
import hydrograph.engine.expression.antlr.ExpressionEditorParser;
import hydrograph.engine.expression.antlr.ExpressionEditorVisitor;
import java.util.HashSet;
import java.util.Set;
/**
* The Class CustomExpressionVisitor .
*
* @author Bitwise
*/
class CustomExpressionVisitor extends ExpressionEditorBaseVisitor<String> implements ExpressionEditorVisitor<String> {
private Set<String> fieldList;
public CustomExpressionVisitor() {
fieldList = new HashSet<String>();
}
@Override
public String visitJavaIdentifier(ExpressionEditorParser.JavaIdentifierContext ctx) {
fieldList.add(ctx.getText());
return visitChildren(ctx);
}
/**
* @return a set of {@link String} objects which contains all the fields
* used in expression.
*/
public Set<String> getFieldList() {
return fieldList;
}
}