IEvaluator.java :  » Algebra » symja » org » matheclipse » parser » client » eval » api » Java Open Source

/*
 * Copyright 2005-2009 Axel Kramer (axelclk@gmail.com)
 *
 * 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.matheclipse.parser.client.eval.api;

import org.matheclipse.parser.client.ast.ASTNode;
import org.matheclipse.parser.client.ast.FunctionNode;
import org.matheclipse.parser.client.eval.BooleanVariable;

/**
 * Interface for <code>java.lang.Object</code> based evaluation engines
 * (typically implemented as <code>IASTVisitor</code>s). For example the
 * <code>ComplexEvalVisitor</code> class uses the <code>Complex</code> class
 * data type.
 * 
 * @param <DATA>
 * @param <DATA_VARIABLE>
 * 
 * @see org.matheclipse.parser.client.eval.api.IASTVisitor
 * @see org.matheclipse.parser.client.eval.ComplexEvalVisitor
 */
public interface IEvaluator<DATA, DATA_VARIABLE> {
  /**
   * Clear all defined variables for this evaluator.
   */
  public void clearVariables();

  /**
   * Define a boolean value for a given variable name.
   * 
   * @param variableName
   * @param value
   */
  public void defineVariable(String variableName, BooleanVariable value);

  /**
   * Define a value for a given variable name.
   * 
   * @param variableName
   * @param value
   */
  public void defineVariable(String variableName, DATA_VARIABLE value);

  /**
   * Evaluate an already parsed in abstract syntax tree node into a
   * <code>DATA</code> value.
   * 
   * @param node
   *          abstract syntax tree node
   * 
   * @return the evaluated DATA
   * 
   */
  public DATA evaluateNode(ASTNode node);

  /**
   * Returns the data variable value to which the specified variableName is
   * mapped, or {@code null} if this map contains no mapping for the
   * variableName.
   * 
   * @param variableName
   * @return
   */
  public DATA_VARIABLE getVariable(String variableName);

  /**
   * Optimize an already parsed in <code>functionNode</code> into an
   * <code>ASTNode</code>.
   * 
   * @param functionNode
   * @return
   * 
   */
  public ASTNode optimizeFunction(final FunctionNode functionNode);
}