com.lyncode.jtwig.parser.JtwigBasicParser Maven / Gradle / Ivy

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/**
 * Copyright 2012 Lyncode
 *
 * 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 com.lyncode.jtwig.parser;

import org.parboiled.BaseParser;
import org.parboiled.Rule;
import org.parboiled.annotations.DontLabel;
import org.parboiled.annotations.MemoMismatches;
import org.parboiled.annotations.SuppressNode;

import static com.lyncode.jtwig.parser.JtwigSymbol.QUOTE;

public class JtwigBasicParser extends BaseParser {
    @SuppressNode
    public Rule spacing () {
        return ZeroOrMore(FirstOf(
                // whitespace
                OneOrMore(AnyOf(" \t\r\n\f").label("Whitespace")),
                // traditional comment
                Sequence("{#", ZeroOrMore(TestNot("#}"), ANY), "#}").label("Comment")
        ));
    }


    public Rule closeCode() {
        return symbol(JtwigSymbol.CLOSE_CODE);
    }

    public Rule openCode() {
        return symbol(JtwigSymbol.OPEN_CODE);
    }

    @MemoMismatches
    public Rule anyKeyword() {
        return Sequence(
                FirstOf(JtwigKeyword.keywords()),
                TestNot(letterOrDigit())
        );
    }


    public Rule identifier() {
        return Sequence(
                TestNot(anyKeyword()),
                letter(),
                ZeroOrMore(letterOrDigit())
        );
    }


    @SuppressNode
    public Rule keyword(JtwigKeyword keyword) {
        return terminal(keyword.getKeyword(), letterOrDigit());
    }



    @SuppressNode
    public Rule symbol(JtwigSymbol symbol) {
        return terminal(symbol.getSymbol());
    }


    @SuppressNode
    @DontLabel
    Rule terminal(String string, Rule mustNotFollow) {
        return Sequence(string, TestNot(mustNotFollow)).label('\'' + string + '\'');
    }


    @SuppressNode
    @DontLabel
    Rule terminal(String string) {
        return String(string).label('\'' + string + '\'');
    }


    public Rule onlyOneChar() {
        return Sequence(
                symbol(QUOTE),
                character(),
                push(match()),
                symbol(QUOTE)
        );
    }

    Rule character() {
        return FirstOf(
                CharRange('a', 'z'),
                CharRange('A', 'Z')
        );
    }

    Rule letter() {
        // switch to this "reduced" character space version for a ~10% parser performance speedup
        return FirstOf(CharRange('a', 'z'), CharRange('A', 'Z'), '_', '$');
    }

    @MemoMismatches
    Rule letterOrDigit() {
        return FirstOf(CharRange('a', 'z'), CharRange('A', 'Z'), CharRange('0', '9'), '_', '$');
    }


    /**
     * Pushes the String (without quotes)
     *
     * @return
     */
    protected Rule stringLiteral() {
        return FirstOf(
                Sequence(
                        '"',
                        ZeroOrMore(
                                FirstOf(
                                        escape(),
                                        Sequence(TestNot(AnyOf("\r\n\"\\")), ANY)
                                )
                        ).suppressSubnodes(),
                        push(match()),
                        '"'
                ),
                Sequence(
                        "'",
                        ZeroOrMore(
                                FirstOf(
                                        escape(),
                                        Sequence(TestNot(AnyOf("\r\n'\\")), ANY)
                                )
                        ).suppressSubnodes(),
                        push(match()),
                        "'"
                )
        );
    }

    Rule escape() {
        return Sequence('\\', FirstOf(AnyOf("btnfr\"\'\\"), octalEscape(), unicodeEscape()));
    }

    Rule octalEscape() {
        return FirstOf(
                Sequence(CharRange('0', '3'), CharRange('0', '7'), CharRange('0', '7')),
                Sequence(CharRange('0', '7'), CharRange('0', '7')),
                CharRange('0', '7')
        );
    }

    Rule unicodeEscape() {
        return Sequence(OneOrMore('u'), hexDigit(), hexDigit(), hexDigit(), hexDigit());
    }

    Rule hexDigit() {
        return FirstOf(CharRange('a', 'f'), CharRange('A', 'F'), CharRange('0', '9'));
    }

    Rule digit() {
        return CharRange('0', '9');
    }
}