TryStatement.java

/* -*- Mode: java; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
 *
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

package org.mozilla.javascript.ast;

import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import org.mozilla.javascript.Token;

/**
 * Try/catch/finally statement. Node type is {@link Token#TRY}.
 *
 * <pre><i>TryStatement</i> :
 *        <b>try</b> Block Catch
 *        <b>try</b> Block Finally
 *        <b>try</b> Block Catch Finally
 * <i>Catch</i> :
 *        <b>catch</b> ( <i><b>Identifier</b></i> ) Block
 * <i>Finally</i> :
 *        <b>finally</b> Block</pre>
 */
public class TryStatement extends AstNode {

    private static final List<CatchClause> NO_CATCHES =
            Collections.unmodifiableList(new ArrayList<>());

    private AstNode tryBlock;
    private List<CatchClause> catchClauses;
    private AstNode finallyBlock;
    private int finallyPosition = -1;

    {
        type = Token.TRY;
    }

    public TryStatement() {}

    public TryStatement(int pos) {
        super(pos);
    }

    public TryStatement(int pos, int len) {
        super(pos, len);
    }

    public AstNode getTryBlock() {
        return tryBlock;
    }

    /**
     * Sets try block. Also sets its parent to this node.
     *
     * @throws IllegalArgumentException} if {@code tryBlock} is {@code null}
     */
    public void setTryBlock(AstNode tryBlock) {
        assertNotNull(tryBlock);
        this.tryBlock = tryBlock;
        tryBlock.setParent(this);
    }

    /**
     * Returns list of {@link CatchClause} nodes. If there are no catch clauses, returns an
     * immutable empty list.
     */
    public List<CatchClause> getCatchClauses() {
        return catchClauses != null ? catchClauses : NO_CATCHES;
    }

    /**
     * Sets list of {@link CatchClause} nodes. Also sets their parents to this node. May be {@code
     * null}. Replaces any existing catch clauses for this node.
     */
    public void setCatchClauses(List<CatchClause> catchClauses) {
        if (catchClauses == null) {
            this.catchClauses = null;
        } else {
            if (this.catchClauses != null) this.catchClauses.clear();
            for (CatchClause cc : catchClauses) {
                addCatchClause(cc);
            }
        }
    }

    /**
     * Add a catch-clause to the end of the list, and sets its parent to this node.
     *
     * @throws IllegalArgumentException} if {@code clause} is {@code null}
     */
    public void addCatchClause(CatchClause clause) {
        assertNotNull(clause);
        if (catchClauses == null) {
            catchClauses = new ArrayList<>();
        }
        catchClauses.add(clause);
        clause.setParent(this);
    }

    /** Returns finally block, or {@code null} if not present */
    public AstNode getFinallyBlock() {
        return finallyBlock;
    }

    /** Sets finally block, and sets its parent to this node. May be {@code null}. */
    public void setFinallyBlock(AstNode finallyBlock) {
        this.finallyBlock = finallyBlock;
        if (finallyBlock != null) finallyBlock.setParent(this);
    }

    /** Returns position of {@code finally} keyword, if present, or -1 */
    public int getFinallyPosition() {
        return finallyPosition;
    }

    /** Sets position of {@code finally} keyword, if present, or -1 */
    public void setFinallyPosition(int finallyPosition) {
        this.finallyPosition = finallyPosition;
    }

    @Override
    public String toSource(int depth) {
        StringBuilder sb = new StringBuilder(250);
        sb.append(makeIndent(depth));
        sb.append("try ");
        if (this.getInlineComment() != null) {
            sb.append(this.getInlineComment().toSource(depth + 1)).append("\n");
        }
        sb.append(tryBlock.toSource(depth).trim());
        for (CatchClause cc : getCatchClauses()) {
            sb.append(cc.toSource(depth));
        }
        if (finallyBlock != null) {
            sb.append(" finally ");
            sb.append(finallyBlock.toSource(depth));
        }
        return sb.toString();
    }

    /** Visits this node, then the try-block, then any catch clauses, and then any finally block. */
    @Override
    public void visit(NodeVisitor v) {
        if (v.visit(this)) {
            tryBlock.visit(v);
            for (CatchClause cc : getCatchClauses()) {
                cc.visit(v);
            }
            if (finallyBlock != null) {
                finallyBlock.visit(v);
            }
        }
    }
}