114 lines
3.6 KiB
Plaintext
114 lines
3.6 KiB
Plaintext
/*
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* [The "BSD license"]
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* Copyright (c) 2011 Terence Parr
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* All rights reserved.
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*
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* Conversion to C#:
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* Copyright (c) 2011 Sam Harwell, Pixel Mine, Inc.
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. The name of the author may not be used to endorse or promote products
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* derived from this software without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
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* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
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* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*/
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grammar Expr;
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/*
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I had to make the following changes to the basic Expr grammar to make it work with the CSharp3 target in "Java compatibility mode".
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For reference, see http://www.antlr.org/wiki/display/ANTLR3/Expression+evaluator.
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Add an options section to set the language to CSharp3.
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In the @header section, add:
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// 'member' is obsolete
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#pragma warning disable 612
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using Antlr.Runtime.JavaExtensions;
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In the @header section, replace:
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import java.util.HashMap;
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with:
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using HashMap = System.Collections.Generic.Dictionary<object,object>;
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Change all instances of "System.out" with "JSystem.@out".
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Change all instances of "System.err" with "JSystem.err".
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Change all instances of "skip()" with "Skip()".
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*/
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options
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{
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language=CSharp3;
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}
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@header {
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// 'member' is obsolete
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#pragma warning disable 612
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using Antlr.Runtime.JavaExtensions;
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using HashMap = System.Collections.Generic.Dictionary<object,object>;
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using Integer = java.lang.Integer;
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}
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@members {
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/** Map variable name to Integer object holding value */
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HashMap memory = new HashMap();
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}
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@lexer::namespace{Antlr3.Runtime.Test.JavaCompat}
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@parser::namespace{Antlr3.Runtime.Test.JavaCompat}
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prog: stat+ ;
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stat: expr NEWLINE {JSystem.@out.println($expr.value);}
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| ID '=' expr NEWLINE
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{memory.put($ID.text, new Integer($expr.value));}
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| NEWLINE
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;
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expr returns [int value]
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: e=multExpr {$value = $e.value;}
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( '+' e=multExpr {$value += $e.value;}
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| '-' e=multExpr {$value -= $e.value;}
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)*
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;
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multExpr returns [int value]
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: e=atom {$value = $e.value;} ('*' e=atom {$value *= $e.value;})*
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;
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atom returns [int value]
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: INT {$value = Integer.parseInt($INT.text);}
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| ID
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{
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Integer v = (Integer)memory.get($ID.text);
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if ( v!=null ) $value = v.intValue();
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else JSystem.err.println("undefined variable "+$ID.text);
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}
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| '(' expr ')' {$value = $expr.value;}
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;
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ID : ('a'..'z'|'A'..'Z')+ ;
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INT : '0'..'9'+ ;
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NEWLINE:'\r'? '\n' ;
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WS : (' '|'\t')+ {Skip();} ;
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