AddAstProductions.java

/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
 * This file is part of SableCC.                             *
 * See the file "LICENSE" for copyright information and the  *
 * terms and conditions for copying, distribution and        *
 * modification of SableCC.                                  *
 * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */

package org.sablecc.sablecc;

import org.sablecc.sablecc.analysis.*;
import org.sablecc.sablecc.node.*;

import java.util.LinkedList;

/*
 * AddAstProductions
 * 
 * This class provide a part of the support of SableCC2.x.x grammars by 
 * SableCC3.x.x.
 * Its role is to add the section Abstract Syntax Tree and its productions
 * to the Grammar based on the Production SectionModel.
 * It's the same result if a copy-paste of Productions section was added
 * to the SableCC2.x.x original grammar and renammed Abstract Syntax Tree.
 */

@SuppressWarnings({"rawtypes", "unchecked"})
public class AddAstProductions extends DepthFirstAdapter {

    LinkedList listAstProd = new TypedLinkedList();
//  private boolean firstAlt;

    public AddAstProductions() {
    }

    @Override
    public void caseAProd(AProd node) {
//    firstAlt = true;
        listOfAstAlts = new TypedLinkedList();

    /*
     * Here, we assume that if there is no Abstract Syntax Tree SectionModel specified
     * in the grammar, no transformations syntax is allowed in Productions section
     */
        if (node.getArrow() != null) {
            error(node.getArrow());
        }

        Object[] list_alt = (Object[]) node.getAlts().toArray();
        for (int i = 0; i < list_alt.length; i++) {
            ((PAlt) list_alt[i]).apply(this);
        }

        AAstProd astProd = new AAstProd(new TId(node.getId().getText()), listOfAstAlts);
        listAstProd.add(astProd);
    }

    @Override
    public void outAGrammar(AGrammar node) {
        node.setAst(new AAst(listAstProd));
    }

    @Override
    public void inAAlt(AAlt node) {
        listElems = new TypedLinkedList();
        processingParsedAlt = true;
    }

    @Override
    public void inAAltTransform(AAltTransform node) {
        if (node.getLBrace() != null) {
            error(node.getLBrace());
        }
    }

    @Override
    public void outAAlt(AAlt node) {
        TId aAltname = node.getAltName() == null ? null : (TId) node.getAltName().clone();
        AAstAlt astAlt = new AAstAlt(aAltname, listElems);

        listOfAstAlts.add(astAlt);
        processingParsedAlt = false;
    }

    boolean processingParsedAlt;

    @Override
    public void inAElem(AElem node) {
        if (processingParsedAlt) {
            AElem tmp = (AElem) node.clone();
            listElems.add(tmp);
        }
    }

    LinkedList listElems;
    LinkedList listOfAstAlts;

    public void error(Token token) {
        throw new RuntimeException(
                "[" + token.getLine() + "," + token.getPos() + "] " +
                        "AST transformations are not allowed because there are no section Abstract Syntax Tree");
    }
}