ASTNode.java

/**
 * Copyright (c) 2014-2017 by the respective copyright holders.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 */
package org.eclipse.smarthome.core.voice.text;

/**
 * Abstract syntax tree node. Result of parsing an expression.
 *
 * @author Tilman Kamp - Initial contribution and API
 *
 */
public class ASTNode {

    private boolean success = false;
    private ASTNode[] children;
    private TokenList remainingTokens;

    private String name;
    private Object value;
    private Object tag;

    public ASTNode() {
    }

    /**
     * Constructs a new AST node.
     *
     * @param children the node's children
     * @param remainingTokens remaining token list starting with the first token that was not covered/consumed
     */
    public ASTNode(ASTNode[] children, TokenList remainingTokens) {
        this.success = true;
        this.children = children;
        this.remainingTokens = remainingTokens;
    }

    /**
     * Breadth searching this (sub-) tree/node for a node with the given name.
     *
     * @param name the name that's used for looking up the tree
     * @return first node with the given name or null, if none was found
     */
    public ASTNode findNode(String name) {
        if (this.name != null && this.name.equals(name)) {
            return this;
        }
        ASTNode n;
        for (ASTNode sn : children) {
            n = sn.findNode(name);
            if (n != null) {
                return n;
            }
        }
        return null;
    }

    /**
     * @return the value of this node as {@link String[]}
     */
    public String[] getValueAsStringArray() {
        Object[] objs = value instanceof Object[] ? (Object[]) value : new Object[] {
                value
        };
        String[] result = new String[objs.length];
        for (int i = 0; i < objs.length; i++) {
            result[i] = objs[i] == null ? "" : ("" + objs[i]);
        }
        return result;
    }

    /**
     * @return the value of this node as {@link String}.
     */
    public String getValueAsString() {
        return value == null ? "" : ("" + value);
    }

    /**
     * Breadth searches this (sub-) tree/node for a node with the given name and returning its value as a
     * {@link String[]}.
     *
     * @param name the name of the named node to be found
     * @return the value of the resulting node as {@link String[]} or null if not found
     */
    public String[] findValueAsStringArray(String name) {
        ASTNode node = findNode(name);
        return node == null ? null : node.getValueAsStringArray();
    }

    /**
     * Breadth searches this (sub-) tree/node for a node with the given name and returning its value as a {@link String}
     * .
     *
     * @param name the name of the named node to be found
     * @return the value of the resulting node as {@link String} or null if not found
     */
    public String findValueAsString(String name) {
        ASTNode node = findNode(name);
        return node == null ? null : node.getValueAsString();
    }

    /**
     * Breadth searches this (sub-) tree/node for a node with the given name and type and returning its value.
     *
     * @param name the name of the named node to be found
     * @param cls the node's value has to be assignable to a reference of this class to match during search
     * @return the value of the resulting node. Null, if not found or the value does not match {@link cls}.
     */
    public Object findValue(String name, Class<?> cls) {
        ASTNode node = findNode(name);
        return node == null ? null
                : ((node.value != null && cls.isAssignableFrom(node.value.getClass())) ? node.value : null);
    }

    /**
     * Breadth searches this (sub-) tree/node for a node with the given name and returning its value.
     *
     * @param name the name of the named node to be found
     * @return the value of the resulting node. Null, if not found.
     */
    public Object findValue(String name) {
        ASTNode node = findNode(name);
        return node == null ? null : node.value;
    }

    /**
     * @return if the node is a valid one (true) or parsing was not successful (false)
     */
    public boolean isSuccess() {
        return success;
    }

    /**
     * @param success if the node is a valid one (true) or parsing was not successful (false)
     */
    public void setSuccess(boolean success) {
        this.success = success;
    }

    /**
     * @return the children
     */
    public ASTNode[] getChildren() {
        return children;
    }

    /**
     * @param children the children to set
     */
    public void setChildren(ASTNode[] children) {
        this.children = children;
    }

    /**
     * @return the remainingTokens
     */
    public TokenList getRemainingTokens() {
        return remainingTokens;
    }

    /**
     * @param remainingTokens the remainingTokens to set
     */
    public void setRemainingTokens(TokenList remainingTokens) {
        this.remainingTokens = remainingTokens;
    }

    /**
     * @return the name
     */
    public String getName() {
        return name;
    }

    /**
     * @param name the name to set
     */
    public void setName(String name) {
        this.name = name;
    }

    /**
     * @return the value
     */
    public Object getValue() {
        return value;
    }

    /**
     * @param value the value to set
     */
    public void setValue(Object value) {
        this.value = value;
    }

    /**
     * @return the tag
     */
    public Object getTag() {
        return tag;
    }

    /**
     * @param tag the tag to set
     */
    public void setTag(Object tag) {
        this.tag = tag;
    }
}