/*
* 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;
/**
* Parselet for all <em>tag setting operations</em> like a /: b = c or a /: b =.
*
* @author patrick (3/27/13)
*/
public class TagSetParselet implements InfixParselet {
private final int myPrecedence;
public TagSetParselet(int precedence) {
this.myPrecedence = precedence;
}
@Override
public MathematicaParser.Result parse(MathematicaParser parser, MathematicaParser.Result left) throws CriticalParserError {
PsiBuilder.Marker tagSetMark = left.getMark().precede();
if (parser.matchesToken(MathematicaElementTypes.TAG_SET)) {
parser.advanceLexer();
} else {
tagSetMark.drop();
throw new CriticalParserError(ParserBundle.message("Critical.tagset"));
}
// In the next line we parse expr1 of expr0/:expr1 and we reduce the precedence by one because it is
// right associative. Using SetDelayed (:=) which has the same precedence the following expression:
// a /: b := c := d is then correctly parsed as a /: b := (c := d)
MathematicaParser.Result expr1 = parser.parseExpression(myPrecedence);
if (!expr1.isValid()) {
parser.error(ParserBundle.message("TagSet.missing.pattern"));
tagSetMark.done(MathematicaElementTypes.TAG_SET_EXPRESSION);
return MathematicaParser.result(tagSetMark, MathematicaElementTypes.TAG_SET_EXPRESSION, false);
}
// IElementType tokenType = parser.getTokenTypeSave(tagSetMark);
IElementType tokenType = parser.getTokenType();
if (tokenType == null) {
parser.error(ParserBundle.message("TagSet.missing.set"));
tagSetMark.done(MathematicaElementTypes.TAG_SET_EXPRESSION);
return MathematicaParser.result(tagSetMark, MathematicaElementTypes.TAG_SET_EXPRESSION, false);
}
// Form expr0 /: expr1 =. where nothing needs to be parsed right of the =.
if (tokenType.equals(MathematicaElementTypes.UNSET)) {
parser.advanceLexer();
tagSetMark.done(MathematicaElementTypes.TAG_UNSET_EXPRESSION);
return MathematicaParser.result(tagSetMark, MathematicaElementTypes.TAG_UNSET_EXPRESSION, expr1.isParsed());
}
// Form expr0 /: expr1 := expr2 or expr0 /: expr1 = expr2 where we need to parse expr2
if ((tokenType.equals(MathematicaElementTypes.SET)) || (tokenType.equals(MathematicaElementTypes.SET_DELAYED))) {
parser.advanceLexer();
MathematicaParser.Result expr2 = parser.parseExpression(myPrecedence);
IElementType endType = tokenType.equals(MathematicaElementTypes.SET) ? MathematicaElementTypes.TAG_SET_EXPRESSION : MathematicaElementTypes.TAG_SET_DELAYED_EXPRESSION;
if (!expr2.isValid()) {
parser.error(ParserBundle.message("General.expr.expected"));
}
tagSetMark.done(endType);
return MathematicaParser.result(tagSetMark, endType, expr1.isParsed() && expr2.isParsed());
}
// if we are here, the second operator (:=, = or =.) is missing and we give up
parser.error(ParserBundle.message("TagSet.missing.set"));
tagSetMark.done(MathematicaElementTypes.TAG_SET_EXPRESSION);
return MathematicaParser.result(tagSetMark, MathematicaElementTypes.TAG_SET_EXPRESSION, false);
}
@Override
public int getMyPrecedence() {
return myPrecedence;
}
}