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/*
* [The "BSD license"]
* Copyright (c) 2011 Terence Parr
* All rights reserved.
*
* Conversion to C#:
* Copyright (c) 2011 Sam Harwell, Pixel Mine, Inc.
* 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
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
grammar Expr;
/*
I had to make the following changes to the basic Expr grammar to make it work with the CSharp3 target in "Java compatibility mode".
For reference, see http://www.antlr.org/wiki/display/ANTLR3/Expression+evaluator.
Add an options section to set the language to CSharp3.
In the @header section, add:
// 'member' is obsolete
#pragma warning disable 612
using Antlr.Runtime.JavaExtensions;
In the @header section, replace:
import java.util.HashMap;
with:
using HashMap = System.Collections.Generic.Dictionary<object,object>;
Change all instances of "System.out" with "JSystem.@out".
Change all instances of "System.err" with "JSystem.err".
Change all instances of "skip()" with "Skip()".
*/
options
{
language=CSharp3;
}
@header {
// 'member' is obsolete
#pragma warning disable 612
using Antlr.Runtime.JavaExtensions;
using HashMap = System.Collections.Generic.Dictionary<object,object>;
using Integer = java.lang.Integer;
}
@members {
/** Map variable name to Integer object holding value */
HashMap memory = new HashMap();
}
@lexer::namespace{Antlr3.Runtime.Test.JavaCompat}
@parser::namespace{Antlr3.Runtime.Test.JavaCompat}
prog: stat+ ;
stat: expr NEWLINE {JSystem.@out.println($expr.value);}
| ID '=' expr NEWLINE
{memory.put($ID.text, new Integer($expr.value));}
| NEWLINE
;
expr returns [int value]
: e=multExpr {$value = $e.value;}
( '+' e=multExpr {$value += $e.value;}
| '-' e=multExpr {$value -= $e.value;}
)*
;
multExpr returns [int value]
: e=atom {$value = $e.value;} ('*' e=atom {$value *= $e.value;})*
;
atom returns [int value]
: INT {$value = Integer.parseInt($INT.text);}
| ID
{
Integer v = (Integer)memory.get($ID.text);
if ( v!=null ) $value = v.intValue();
else JSystem.err.println("undefined variable "+$ID.text);
}
| '(' expr ')' {$value = $expr.value;}
;
ID : ('a'..'z'|'A'..'Z')+ ;
INT : '0'..'9'+ ;
NEWLINE:'\r'? '\n' ;
WS : (' '|'\t')+ {Skip();} ;
|
