com.oracle.truffle.regex.tregex.parser.ast.Term Maven / Gradle / Ivy

Go to download
/*
 * Copyright (c) 2018, 2020, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * The Universal Permissive License (UPL), Version 1.0
 *
 * Subject to the condition set forth below, permission is hereby granted to any
 * person obtaining a copy of this software, associated documentation and/or
 * data (collectively the "Software"), free of charge and under any and all
 * copyright rights in the Software, and any and all patent rights owned or
 * freely licensable by each licensor hereunder covering either (i) the
 * unmodified Software as contributed to or provided by such licensor, or (ii)
 * the Larger Works (as defined below), to deal in both
 *
 * (a) the Software, and
 *
 * (b) any piece of software and/or hardware listed in the lrgrwrks.txt file if
 * one is included with the Software each a "Larger Work" to which the Software
 * is contributed by such licensors),
 *
 * without restriction, including without limitation the rights to copy, create
 * derivative works of, display, perform, and distribute the Software and make,
 * use, sell, offer for sale, import, export, have made, and have sold the
 * Software and the Larger Work(s), and to sublicense the foregoing rights on
 * either these or other terms.
 *
 * This license is subject to the following condition:
 *
 * The above copyright notice and either this complete permission notice or at a
 * minimum a reference to the UPL must 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 com.oracle.truffle.regex.tregex.parser.ast;

import com.oracle.truffle.regex.UnsupportedRegexException;
import com.oracle.truffle.regex.tregex.TRegexOptions;
import com.oracle.truffle.regex.tregex.automaton.AbstractState;
import com.oracle.truffle.regex.tregex.buffer.CompilationBuffer;
import com.oracle.truffle.regex.tregex.nfa.ASTTransition;

/**
 * A common supertype for all {@link RegexASTNode}s except {@link Sequence}s.
 * 
 * Roughly corresponds to the goal symbol Term in the ECMAScript RegExp syntax. A
 * Term ({@link Term}) can be either an Assertion ({@link PositionAssertion} or
 * {@link LookAroundAssertion}) or an Atom ({@link QuantifiableTerm}.
 */
public abstract class Term extends RegexASTNode implements AbstractState {

    private int seqIndex = 0;

    Term() {
    }

    Term(Term copy) {
        super(copy);
    }

    @Override
    public abstract Term copy(RegexAST ast);

    @Override
    public abstract Term copyRecursive(RegexAST ast, CompilationBuffer compilationBuffer);

    public int getSeqIndex() {
        return seqIndex;
    }

    public void setSeqIndex(int seqIndex) {
        this.seqIndex = seqIndex;
        if (seqIndex > TRegexOptions.TRegexParserTreeMaxNumberOfTermsInSequence) {
            throw new UnsupportedRegexException("too many terms in a single sequence");
        }
    }

    @Override
    public RegexASTSubtreeRootNode getSubTreeParent() {
        RegexASTNode current = this;
        while (current.getParent() != null) {
            assert current instanceof Term;
            if (current.getParent() instanceof RegexASTSubtreeRootNode) {
                return (RegexASTSubtreeRootNode) current.getParent();
            }
            // structure is always Group -> Sequence -> Term
            current = current.getParent().getParent();
        }
        // this should only be reached by nodes generated by RegexAST#createNFAInitialStates()!
        return null;
    }
}