graal/21.0.0.2 : graal-js/com.oracle.js.parser/com/oracle/js/parser/ir/ForNode.java

/*
 * Copyright (c) 2010, 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.js.parser.ir;

import com.oracle.js.parser.ir.visitor.NodeVisitor;
import com.oracle.js.parser.ir.visitor.TranslatorNodeVisitor;

IR representing a FOR statement.
/**
 * IR representing a FOR statement.
 */
public final class ForNode extends LoopNode {
    Initialize expression for an ordinary for statement, or the LHS expression receiving
iterated-over values in a for-in statement.
/**
     * Initialize expression for an ordinary for statement, or the LHS expression receiving
     * iterated-over values in a for-in statement.
     */
    private final Expression init;

    Modify expression for an ordinary statement, or the source of the iterator in the for-in
statement.
/**
     * Modify expression for an ordinary statement, or the source of the iterator in the for-in
     * statement.
     */
    private final JoinPredecessorExpression modify;

    Iterator symbol. /** Iterator symbol. */
    private Symbol iterator;

    Is this a normal for in loop? /** Is this a normal for in loop? */
    public static final int IS_FOR_IN = 1 << 0;

    Is this a normal for each in loop? /** Is this a normal for each in loop? */
    public static final int IS_FOR_EACH = 1 << 1;

    Does this loop need a per-iteration scope because its init contain a LET declaration? /** Does this loop need a per-iteration scope because its init contain a LET declaration? */
    public static final int PER_ITERATION_SCOPE = 1 << 2;

    Is this a for of loop? /** Is this a for of loop? */
    public static final int IS_FOR_OF = 1 << 3;

    Is this a for await of loop? /** Is this a for await of loop? */
    public static final int IS_FOR_AWAIT_OF = 1 << 4;

    private final int flags;

    Constructor
Params: lineNumber – The line number of header
token – The for token
finish – The last character of the for node
body – The body of the for node
flags – The flags
init – The initial expression
test – The test expression
modify – The modify expression/**
     * Constructor
     *
     * @param lineNumber The line number of header
     * @param token The for token
     * @param finish The last character of the for node
     * @param body The body of the for node
     * @param flags The flags
     * @param init The initial expression
     * @param test The test expression
     * @param modify The modify expression
     */
    public ForNode(final int lineNumber, final long token, final int finish, final Block body, final int flags, final Expression init, final JoinPredecessorExpression test,
                    final JoinPredecessorExpression modify) {
        super(lineNumber, token, finish, body, test, false);
        this.flags = flags;
        this.init = init;
        this.modify = modify;

    }

    private ForNode(final ForNode forNode, final Expression init, final JoinPredecessorExpression test,
                    final Block body, final JoinPredecessorExpression modify, final int flags, final boolean controlFlowEscapes) {
        super(forNode, test, body, controlFlowEscapes);
        this.init = init;
        this.modify = modify;
        this.flags = flags;
        // Even if the for node gets cloned in try/finally, the symbol can be shared as only one
        // branch of the finally
        // is executed.
        this.iterator = forNode.iterator;
    }

    @Override
    public Node accept(final LexicalContext lc, final NodeVisitor<? extends LexicalContext> visitor) {
        if (visitor.enterForNode(this)) {
            //@formatter:off
            return visitor.leaveForNode(
                setInit(lc, init == null ? null : (Expression) init.accept(visitor)).
                setTest(lc, test == null ? null : (JoinPredecessorExpression) test.accept(visitor)).
                setModify(lc, modify == null ? null : (JoinPredecessorExpression) modify.accept(visitor)).
                setBody(lc, (Block) body.accept(visitor)));
            //@formatter:on
        }

        return this;
    }

    @Override
    public <R> R accept(LexicalContext lc, TranslatorNodeVisitor<? extends LexicalContext, R> visitor) {
        return visitor.enterForNode(this);
    }

    @Override
    public void toString(final StringBuilder sb, final boolean printTypes) {
        sb.append("for");
        sb.append(' ');
        if (isForEach()) {
            sb.append("each ");
        }
        sb.append('(');

        if (isForIn()) {
            init.toString(sb, printTypes);
            sb.append(" in ");
            modify.toString(sb, printTypes);
        } else if (isForOf()) {
            init.toString(sb, printTypes);
            sb.append(" of ");
            modify.toString(sb, printTypes);
        } else {
            if (init != null) {
                init.toString(sb, printTypes);
            }
            sb.append("; ");
            if (test != null) {
                test.toString(sb, printTypes);
            }
            sb.append("; ");
            if (modify != null) {
                modify.toString(sb, printTypes);
            }
        }

        sb.append(')');
    }

    @Override
    public boolean hasGoto() {
        return !isForInOrOf() && test == null;
    }

    @Override
    public boolean mustEnter() {
        if (isForInOrOf()) {
            return false; // may be an empty set to iterate over, then we skip the loop
        }
        return test == null;
    }

    Get the initialization expression for this for loop
Returns: the initialization expression/**
     * Get the initialization expression for this for loop
     *
     * @return the initialization expression
     */
    public Expression getInit() {
        return init;
    }

    Reset the initialization expression for this for loop
Params: lc – lexical context
init – new initialization expression
Returns: new for node if changed or existing if not/**
     * Reset the initialization expression for this for loop
     *
     * @param lc lexical context
     * @param init new initialization expression
     * @return new for node if changed or existing if not
     */
    public ForNode setInit(final LexicalContext lc, final Expression init) {
        if (this.init == init) {
            return this;
        }
        return Node.replaceInLexicalContext(lc, this, new ForNode(this, init, test, body, modify, flags, controlFlowEscapes));
    }

    Is this a for in construct rather than a standard init;condition;modification one
Returns: true if this is a for in construct/**
     * Is this a for in construct rather than a standard init;condition;modification one
     *
     * @return true if this is a for in construct
     */
    public boolean isForIn() {
        return (flags & IS_FOR_IN) != 0;
    }

    Is this a (non-standard) for each construct, known from e.g. Rhino.
Returns: true if this is a for each construct/**
     * Is this a (non-standard) for each construct, known from e.g. Rhino.
     *
     * @return true if this is a for each construct
     */
    public boolean isForEach() {
        return (flags & IS_FOR_EACH) != 0;
    }

    Is this an ECMAScript 6 for of construct.
Returns: true if this is a for of construct/**
     * Is this an ECMAScript 6 for of construct.
     *
     * @return true if this is a for of construct
     */
    public boolean isForOf() {
        return (flags & IS_FOR_OF) != 0;
    }

    Is this an ECMAScript 8 for-await-of construct.
Returns: true if this is a for-await-of construct/**
     * Is this an ECMAScript 8 for-await-of construct.
     *
     * @return true if this is a for-await-of construct
     */
    public boolean isForAwaitOf() {
        return (flags & IS_FOR_AWAIT_OF) != 0;
    }

    Is this a for-in or for-of statement?
Returns: true if this is a for-in or for-of loop/**
     * Is this a for-in or for-of statement?
     *
     * @return true if this is a for-in or for-of loop
     */
    public boolean isForInOrOf() {
        return isForIn() || isForOf() || isForAwaitOf();
    }

    If this is a for in or for each construct, there is an iterator symbol
Returns: the symbol for the iterator to be used, or null if none exists/**
     * If this is a for in or for each construct, there is an iterator symbol
     *
     * @return the symbol for the iterator to be used, or null if none exists
     */
    public Symbol getIterator() {
        return iterator;
    }

    Assign an iterator symbol to this ForNode. Used for for in and for each constructs
Params: iterator – the iterator symbol/**
     * Assign an iterator symbol to this ForNode. Used for for in and for each constructs
     *
     * @param iterator the iterator symbol
     */
    public void setIterator(final Symbol iterator) {
        this.iterator = iterator;
    }

    Get the modification expression for this ForNode
Returns: the modification expression/**
     * Get the modification expression for this ForNode
     *
     * @return the modification expression
     */
    public JoinPredecessorExpression getModify() {
        return modify;
    }

    Reset the modification expression for this ForNode
Params: lc – lexical context
modify – new modification expression
Returns: new for node if changed or existing if not/**
     * Reset the modification expression for this ForNode
     *
     * @param lc lexical context
     * @param modify new modification expression
     * @return new for node if changed or existing if not
     */
    public ForNode setModify(final LexicalContext lc, final JoinPredecessorExpression modify) {
        if (this.modify == modify) {
            return this;
        }
        return Node.replaceInLexicalContext(lc, this, new ForNode(this, init, test, body, modify, flags, controlFlowEscapes));
    }

    @Override
    public ForNode setTest(final LexicalContext lc, final JoinPredecessorExpression test) {
        if (this.test == test) {
            return this;
        }
        return Node.replaceInLexicalContext(lc, this, new ForNode(this, init, test, body, modify, flags, controlFlowEscapes));
    }

    @Override
    public Block getBody() {
        return body;
    }

    @Override
    public ForNode setBody(final LexicalContext lc, final Block body) {
        if (this.body == body) {
            return this;
        }
        return Node.replaceInLexicalContext(lc, this, new ForNode(this, init, test, body, modify, flags, controlFlowEscapes));
    }

    @Override
    public ForNode setControlFlowEscapes(final LexicalContext lc, final boolean controlFlowEscapes) {
        if (this.controlFlowEscapes == controlFlowEscapes) {
            return this;
        }
        return Node.replaceInLexicalContext(lc, this, new ForNode(this, init, test, body, modify, flags, controlFlowEscapes));
    }

    @Override
    public boolean hasPerIterationScope() {
        return (flags & PER_ITERATION_SCOPE) != 0;
    }
}
Params:	lc – lexical context init – new initialization expression
Returns:	new for node if changed or existing if not
Params:	lc – lexical context modify – new modification expression
Returns:	new for node if changed or existing if not
/

graal/ 21.0.0.2/ graal-js/com.oracle.js.parser/com/oracle/js/parser/ir/ForNode.java
