001    /*
002     * Copyright 2010-2015 JetBrains s.r.o.
003     *
004     * Licensed under the Apache License, Version 2.0 (the "License");
005     * you may not use this file except in compliance with the License.
006     * You may obtain a copy of the License at
007     *
008     * http://www.apache.org/licenses/LICENSE-2.0
009     *
010     * Unless required by applicable law or agreed to in writing, software
011     * distributed under the License is distributed on an "AS IS" BASIS,
012     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013     * See the License for the specific language governing permissions and
014     * limitations under the License.
015     */
016    
017    package org.jetbrains.kotlin.parsing;
018    
019    import com.intellij.psi.tree.IElementType;
020    
021    public interface TokenStreamPattern {
022        /**
023         * Called on each token
024         *
025         * @param offset
026         * @param topLevel see {@link #isTopLevel(int, int, int, int)}
027         * @return <code>true</code> to stop
028         */
029        boolean processToken(int offset, boolean topLevel);
030    
031        /**
032         * @return the position where the predicate has matched, -1 if no match was found
033         */
034        int result();
035    
036        /**
037         * Decides if the combination of open bracket counts makes a "top level position"
038         * Straightforward meaning would be: if all counts are zero, then it's a top level
039         */
040        boolean isTopLevel(int openAngleBrackets, int openBrackets, int openBraces, int openParentheses);
041    
042        /**
043         * Called on right parentheses, brackets, braces and angles (>)
044         * @param token the closing bracket
045         * @return true to stop matching, false to proceed
046         */
047        boolean handleUnmatchedClosing(IElementType token);
048    }