001//
002// MIT License
003//
004// Copyright (c) 2021 Alexander Söderberg & Contributors
005//
006// Permission is hereby granted, free of charge, to any person obtaining a copy
007// of this software and associated documentation files (the "Software"), to deal
008// in the Software without restriction, including without limitation the rights
009// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
010// copies of the Software, and to permit persons to whom the Software is
011// furnished to do so, subject to the following conditions:
012//
013// The above copyright notice and this permission notice shall be included in all
014// copies or substantial portions of the Software.
015//
016// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
017// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
018// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
019// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
020// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
021// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
022// SOFTWARE.
023//
024package cloud.commandframework.internal;
025
026import org.checkerframework.checker.nullness.qual.NonNull;
027
028import java.util.LinkedList;
029import java.util.StringTokenizer;
030
031/**
032 * Tokenizer that splits command inputs into tokens. This will split the string
033 * at every blank space. If the input string ends with a blank space, a trailing
034 * empty string will be added to the token list
035 */
036public final class CommandInputTokenizer {
037
038    private static final String DELIMITER = " ";
039    private static final String EMPTY = "";
040
041    private final StringTokenizerFactory stringTokenizerFactory = new StringTokenizerFactory();
042    private final String input;
043
044    /**
045     * Create a new input tokenizer
046     *
047     * @param input Input that is to be turned into tokens
048     */
049    public CommandInputTokenizer(final @NonNull String input) {
050        this.input = input;
051    }
052
053    /**
054     * Turn the input into tokens
055     *
056     * @return Linked list containing the tokenized input
057     */
058    public @NonNull LinkedList<@NonNull String> tokenize() {
059        final StringTokenizer stringTokenizer = stringTokenizerFactory.createStringTokenizer();
060        final LinkedList<String> tokens = new LinkedList<>();
061        while (stringTokenizer.hasMoreElements()) {
062            tokens.add(stringTokenizer.nextToken());
063        }
064        if (input.endsWith(DELIMITER)) {
065            tokens.add(EMPTY);
066        }
067        return tokens;
068    }
069
070
071    /**
072     * Factory class that creates {@link StringTokenizer} instances
073     */
074    private final class StringTokenizerFactory {
075
076        private @NonNull StringTokenizer createStringTokenizer() {
077            return new StringTokenizer(input, DELIMITER);
078        }
079
080    }
081
082}