WhitespaceOrLetterState.java

/*
 * #%L
 * Native ARchive plugin for Maven
 * %%
 * Copyright (C) 2002 - 2014 NAR Maven Plugin developers.
 * %%
 * 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.
 * #L%
 */
package com.github.maven_nar.cpptasks.parser;

/**
 * This parser state checks consumed characters against a specific character or
 * whitespace.
 *
 * @author Curt Arnold
 */
public final class WhitespaceOrLetterState extends AbstractParserState {
  /**
   * Next state if the character is found.
   */
  private final AbstractParserState nextState;

  /**
   * Character to match.
   */
  private final char thisLetter;

  /**
   * Constructor.
   *
   * @param parser
   *          parser
   * @param matchLetter
   *          letter to match
   * @param nextStateArg
   *          next state if a match on the letter
   */
  public WhitespaceOrLetterState(final AbstractParser parser, final char matchLetter,
      final AbstractParserState nextStateArg) {
    super(parser);
    this.thisLetter = matchLetter;
    this.nextState = nextStateArg;
  }

  /**
   * Consumes a character and returns the next state for the parser.
   *
   * @param ch
   *          next character @returns the configured nextState if ch is the
   *          expected character or the configure noMatchState otherwise.
   * @return next state
   */
  @Override
  public AbstractParserState consume(final char ch) {
    if (ch == this.thisLetter) {
      return this.nextState;
    }
    if (ch == ' ' || ch == '\t') {
      return this;
    }
    if (ch == '\n') {
      getParser().getNewLineState();
    }
    return null;
  }
}