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      1 /*
      2  * [The "BSD license"]
      3  *  Copyright (c) 2010 Terence Parr
      4  *  All rights reserved.
      5  *
      6  *  Redistribution and use in source and binary forms, with or without
      7  *  modification, are permitted provided that the following conditions
      8  *  are met:
      9  *  1. Redistributions of source code must retain the above copyright
     10  *      notice, this list of conditions and the following disclaimer.
     11  *  2. Redistributions in binary form must reproduce the above copyright
     12  *      notice, this list of conditions and the following disclaimer in the
     13  *      documentation and/or other materials provided with the distribution.
     14  *  3. The name of the author may not be used to endorse or promote products
     15  *      derived from this software without specific prior written permission.
     16  *
     17  *  THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
     18  *  IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
     19  *  OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
     20  *  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
     21  *  INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
     22  *  NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     23  *  DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     24  *  THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     25  *  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
     26  *  THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     27  */
     28 package org.antlr.codegen;
     29 
     30 import org.antlr.analysis.Label;
     31 import org.antlr.tool.AttributeScope;
     32 import org.antlr.tool.Grammar;
     33 import org.antlr.tool.RuleLabelScope;
     34 
     35 public class Perl5Target extends Target {
     36     public Perl5Target() {
     37         targetCharValueEscape['$'] = "\\$";
     38         targetCharValueEscape['@'] = "\\@";
     39         targetCharValueEscape['%'] = "\\%";
     40         AttributeScope.tokenScope.addAttribute("self", null);
     41         RuleLabelScope.predefinedLexerRulePropertiesScope.addAttribute("self", null);
     42     }
     43 
     44     public String getTargetCharLiteralFromANTLRCharLiteral(final CodeGenerator generator,
     45                                                            final String literal) {
     46         final StringBuffer buf = new StringBuffer(10);
     47 
     48         final int c = Grammar.getCharValueFromGrammarCharLiteral(literal);
     49         if (c < Label.MIN_CHAR_VALUE) {
     50             buf.append("\\x{0000}");
     51         } else if (c < targetCharValueEscape.length &&
     52                 targetCharValueEscape[c] != null) {
     53             buf.append(targetCharValueEscape[c]);
     54         } else if (Character.UnicodeBlock.of((char) c) ==
     55                 Character.UnicodeBlock.BASIC_LATIN &&
     56                 !Character.isISOControl((char) c)) {
     57             // normal char
     58             buf.append((char) c);
     59         } else {
     60             // must be something unprintable...use \\uXXXX
     61             // turn on the bit above max "\\uFFFF" value so that we pad with zeros
     62             // then only take last 4 digits
     63             String hex = Integer.toHexString(c | 0x10000).toUpperCase().substring(1, 5);
     64             buf.append("\\x{");
     65             buf.append(hex);
     66             buf.append("}");
     67         }
     68 
     69         if (buf.indexOf("\\") == -1) {
     70             // no need for interpolation, use single quotes
     71             buf.insert(0, '\'');
     72             buf.append('\'');
     73         } else {
     74             // need string interpolation
     75             buf.insert(0, '\"');
     76             buf.append('\"');
     77         }
     78 
     79         return buf.toString();
     80     }
     81 
     82     public String encodeIntAsCharEscape(final int v) {
     83         final int intValue;
     84         if ((v & 0x8000) == 0) {
     85             intValue = v;
     86         } else {
     87             intValue = -(0x10000 - v);
     88         }
     89 
     90         return String.valueOf(intValue);
     91     }
     92 }
     93