GroupParselet.java

/*
 * Copyright (c) 2013 Patrick Scheibe
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */

package de.halirutan.mathematica.parsing.prattparser.parselets;

import com.intellij.lang.PsiBuilder;
import com.intellij.psi.tree.IElementType;
import de.halirutan.mathematica.parsing.MathematicaElementTypes;
import de.halirutan.mathematica.parsing.ParserBundle;
import de.halirutan.mathematica.parsing.prattparser.CriticalParserError;
import de.halirutan.mathematica.parsing.prattparser.MathematicaParser;
import de.halirutan.mathematica.parsing.prattparser.ParseletProvider;

/**
 * Parselet for grouping (2+3)*4
 *
 * @author patrick (3/27/13)
 */
public class GroupParselet implements PrefixParselet {

  final int myPrecedence;

  public GroupParselet(int precedence) {
    this.myPrecedence = precedence;
  }

  @Override
  public MathematicaParser.Result parse(MathematicaParser parser) throws CriticalParserError {
    // should never happen
    if (!parser.getTokenType().equals(MathematicaElementTypes.LEFT_PAR)) {
      return MathematicaParser.notParsed();
    }
    IElementType token = ParseletProvider.getPrefixPsiElement(this);
    PsiBuilder.Marker groupMark = parser.mark();
    parser.advanceLexer();

    if (parser.eof()) {
      parser.error(ParserBundle.message("General.eof"));
      groupMark.drop();
      return MathematicaParser.notParsed();
    }

    MathematicaParser.Result result = parser.parseExpression();
    if (parser.matchesToken(MathematicaElementTypes.RIGHT_PAR)) {
      parser.advanceLexer();
      groupMark.done(token);

      // if we find a closing ) we return the group as parsed successful, no matter whether
      // the containing expression was parsed. Errors in the expression are marked there anyway.
      result = MathematicaParser.result(groupMark, token, true);
    } else {
      // when the grouped expr was parsed successfully and we just don't find the closing parenthesis we
      // create an error mark there. Otherwise we just return "not parsed" since something seems to be really
      // broken.
      if (result.isParsed()) {
        parser.error(ParserBundle.message("General.closing", "')'"));
        groupMark.done(token);
        result = MathematicaParser.result(groupMark, token, false);
      } else {
        result = MathematicaParser.notParsed();
        groupMark.drop();
      }
    }
    return result;
  }

  public int getPrecedence() {
    return myPrecedence;
  }
}