antlr-3.4/tool/src/main/java/org/antlr/codegen/Perl5Target.java

/*
 * [The "BSD license"]
 *  Copyright (c) 2010 Terence Parr
 *  All rights reserved.
 *
 *  Redistribution and use in source and binary forms, with or without
 *  modification, are permitted provided that the following conditions
 *  are met:
 *  1. Redistributions of source code must retain the above copyright
 *      notice, this list of conditions and the following disclaimer.
 *  2. Redistributions in binary form must reproduce the above copyright
 *      notice, this list of conditions and the following disclaimer in the
 *      documentation and/or other materials provided with the distribution.
 *  3. The name of the author may not be used to endorse or promote products
 *      derived from this software without specific prior written permission.
 *
 *  THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 *  IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 *  OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 *  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 *  INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 *  NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 *  DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 *  THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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 *  THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
package org.antlr.codegen;

import org.antlr.analysis.Label;
import org.antlr.tool.AttributeScope;
import org.antlr.tool.Grammar;
import org.antlr.tool.RuleLabelScope;

public class Perl5Target extends Target {
    public Perl5Target() {
        targetCharValueEscape['$'] = "\\$";
        targetCharValueEscape['@'] = "\\@";
        targetCharValueEscape['%'] = "\\%";
        AttributeScope.tokenScope.addAttribute("self", null);
        RuleLabelScope.predefinedLexerRulePropertiesScope.addAttribute("self", null);
    }

    public String getTargetCharLiteralFromANTLRCharLiteral(final CodeGenerator generator,
                                                           final String literal) {
        final StringBuffer buf = new StringBuffer(10);

        final int c = Grammar.getCharValueFromGrammarCharLiteral(literal);
        if (c < Label.MIN_CHAR_VALUE) {
            buf.append("\\x{0000}");
        } else if (c < targetCharValueEscape.length &&
                targetCharValueEscape[c] != null) {
            buf.append(targetCharValueEscape[c]);
        } else if (Character.UnicodeBlock.of((char) c) ==
                Character.UnicodeBlock.BASIC_LATIN &&
                !Character.isISOControl((char) c)) {
            // normal char
            buf.append((char) c);
        } else {
            // must be something unprintable...use \\uXXXX
            // turn on the bit above max "\\uFFFF" value so that we pad with zeros
            // then only take last 4 digits
            String hex = Integer.toHexString(c | 0x10000).toUpperCase().substring(1, 5);
            buf.append("\\x{");
            buf.append(hex);
            buf.append("}");
        }

        if (buf.indexOf("\\") == -1) {
            // no need for interpolation, use single quotes
            buf.insert(0, '\'');
            buf.append('\'');
        } else {
            // need string interpolation
            buf.insert(0, '\"');
            buf.append('\"');
        }

        return buf.toString();
    }

    public String encodeIntAsCharEscape(final int v) {
        final int intValue;
        if ((v & 0x8000) == 0) {
            intValue = v;
        } else {
            intValue = -(0x10000 - v);
        }

        return String.valueOf(intValue);
    }
}