Groovy example source code file (JsonTokenType.java)

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Java - Groovy tags/keywords

close_bracket, close_bracket, close_curly, comma, false, jsontokentype, jsontokentype, null, object, object, open_bracket, regex, string, string, true

The Groovy JsonTokenType.java source code

/*
 * Copyright 2003-2011 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package groovy.json;

import java.util.regex.Matcher;
import java.util.regex.Pattern;

/**
 * Enum listing all the possible JSON tokens that should be recognized by the lexer.
 *
 * @author Guillaume Laforge
 * @since 1.8.0
 */
public enum JsonTokenType {
    OPEN_CURLY      ( "an openning curly brace '{'",        "{"         ),
    CLOSE_CURLY     ( "a closing curly brace '}'",          "}"         ),
    OPEN_BRACKET    ( "an openning square bracket '['",     "["         ),
    CLOSE_BRACKET   ( "a closing square bracket ']'",       "]"         ),
    COLON           ( "a colon ':'",                        ":"         ),
    COMMA           ( "a comma ','",                        ","         ),
    NULL            ( "the constant 'null'",                "null"      ),
    TRUE            ( "the constant 'true'",                "true"      ),
    FALSE           ( "the constant 'false'",               "false"     ),
    NUMBER          ( "a number",                           Pattern.compile("-?\\d+(\\.\\d+)?((e|E)(\\+|-)?\\d+)?")),
    STRING          ( "a string",                           Pattern.compile("\"([^\"\\\\]*|\\\\[\"\\\\bfnrt\\/]|\\\\u[0-9a-fA-F]{4})*\"", Pattern.DOTALL));

    /**
     * A String constant or a Pattern, serving as a validator for matching tokens.
     */
    private Object validator;

    /**
     * A label describing the token
     */
    private String label;

    /**
     * Construct a token type with a label and a validator
     *
     * @param label a label describing the token
     * @param validator a String or Pattern validating input strings as valid tokens
     */
    JsonTokenType(String label, Object validator) {
        this.validator = validator;
        this.label = label;
    }

    /**
     * Tells if an input string matches a token.
     *
     * @param input the input string to match
     *
     * @return a <code>Matching enum value:
     * <code>YES if this is an exact match,
     * <code>POSSIBLE if more characters could turn the input string into a valid token,
     * or <code>NO if the string cannot possibly match the pattern even with more characters to read.
     */
    public boolean matching(String input) {
        if (validator instanceof Pattern) {
            Matcher matcher = ((Pattern)validator).matcher(input);
            return matcher.matches();
        } else if (validator instanceof String) {
            return input.equals(validator);
        } else {
            return false;
        }
    }

    /**
     * Find which JSON value might be starting with a given character
     *
     * @param c the character
     * @return the possible token type found
     */
    public static JsonTokenType startingWith(char c) {
        switch (c) {
            case '{': return OPEN_CURLY;
            case '}': return CLOSE_CURLY;
            case '[': return OPEN_BRACKET;
            case ']': return CLOSE_BRACKET;
            case ',': return COMMA;
            case ':': return COLON;

            case 't': return TRUE;
            case 'f': return FALSE;
            case 'n': return NULL;

            case '"': return STRING;

            case '-':
            case '0':
            case '1':
            case '2':
            case '3':
            case '4':
            case '5':
            case '6':
            case '7':
            case '8':
            case '9':
                return NUMBER;
        }
        return null;
    }

    public String getLabel() {
        return label;
    }

    public Object getValidator() {
        return validator;
    }
}