001/*
002 * ModeShape (http://www.modeshape.org)
003 *
004 * Licensed under the Apache License, Version 2.0 (the "License");
005 * you may not use this file except in compliance with the License.
006 * You may obtain a copy of the License at
007 *
008 *       http://www.apache.org/licenses/LICENSE-2.0
009 *
010 * Unless required by applicable law or agreed to in writing, software
011 * distributed under the License is distributed on an "AS IS" BASIS,
012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013 * See the License for the specific language governing permissions and
014 * limitations under the License.
015 */
016package org.modeshape.sequencer.ddl;
017
018import org.modeshape.common.text.ParsingException;
019import org.modeshape.sequencer.ddl.node.AstNode;
020
021/**
022 * Interface for parsing DDL files.
023 */
024public interface DdlParser {
025
026    /**
027     * Determine this parser's score for the given DDL string. This method is called to determine how well this parser handles the
028     * supplied DDL, and is often called before the {@link #parse(String, AstNode, Object)} method.
029     * 
030     * @param ddl the input string to parse; may not be null
031     * @param fileName the name of the DDL content, which may be used to improve the score; may be null if not known
032     * @param scorer the scorer that should be used to record the score; may not be null
033     * @return an object that will be passed to the {@link #parse(String, AstNode,Object)} method
034     * @throws ParsingException if there is an error parsing the supplied DDL content
035     */
036    public Object score( String ddl,
037                         String fileName,
038                         DdlParserScorer scorer ) throws ParsingException;
039
040    /**
041     * Parses a DDL string, adding child {@link AstNode}s and properties to the supplied root. This method instantiates the
042     * tokenizer, calls a method to allow subclasses to register keywords and statement start phrases with the tokenizer and
043     * finally performs the tokenizing (i.e. tokens.start()) before calling the actual parse method.
044     * 
045     * @param ddl the input string to parse; may not be null
046     * @param rootNode the top level {@link AstNode}; may not be null
047     * @param scoreReturnObject the object returned from {@link #score(String, String, DdlParserScorer)} for the same DDL content;
048     *        may be null if the {@link #score(String, String, DdlParserScorer)} method was not called
049     * @throws ParsingException if there is an error parsing the supplied DDL content
050     */
051    public void parse( String ddl,
052                       AstNode rootNode,
053                       Object scoreReturnObject ) throws ParsingException;
054
055    /**
056     * Get the identifier for this parser.
057     * 
058     * @return the parser's identifier; never null
059     */
060    public String getId();
061
062    /**
063     * Allows parsers to post process the {@link AstNode} tree given the supplied root. Initial use-case would be to allow a
064     * second pass through the tree to resolve any table references (FK's) that were defined out of order in the DDL
065     * 
066     * @param rootNode the top level {@link AstNode}; may not be null
067     */
068    public void postProcess( AstNode rootNode );
069
070}