update grammars

[git-p4: depot-paths = "//depot/code/antlr4/main/": change = 9856]
This commit is contained in:
parrt 2012-01-11 11:21:05 -08:00
parent b3c187e6c3
commit 73793898a9
3 changed files with 109 additions and 10 deletions

16
tool/playground/A.g4 Normal file
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@ -0,0 +1,16 @@
grammar A;
s : q=e {System.out.println("result = "+$e.v);} ;
e returns [int v]
: a=e '*' b=e {$v = $a.v * $b.v;} -> mult
| a=e '+' b=e {$v = $a.v + $b.v;} -> add
| INT {$v = $INT.int;}
| '(' x=e ')' {$v = $x.v;}
| e '++' -> inc
| e '--'
| ID -> anID
;
INT : '0'..'9'+ ;
WS : (' '|'\n')+ {skip();} ;

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/*
[The "BSD license"]
Copyright (c) 2011 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
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
import org.antlr.v4.runtime.*;
import org.antlr.v4.runtime.tree.ParseTree;
import org.antlr.v4.runtime.tree.ParseTreeWalker;
public class TestA {
public static class Do extends BlankAListener {
Parser p;
public Do(Parser p ) { this.p = p; }
@Override
public void exitEveryRule(ParserRuleContext<Token> ctx) {
System.out.println("exit "+ctx.toStringTree(p));
}
@Override
public void enterRule(AParser.eContext ctx) {
System.out.println("enter alt w/o -> label: "+ctx.toInfoString(p));
}
@Override
public void visitTerminal(ParserRuleContext<Token> ctx, Token symbol) {
if ( ctx instanceof AParser.eContext && symbol.getType()==AParser.INT ) {
AParser.eContext ectx = (AParser.eContext)ctx;
ectx.v = Integer.valueOf(symbol.getText());
}
}
@Override
public void exitRule(AParser.multContext ctx) {
System.out.println("mult "+ctx.a.v+" * "+ctx.b.v);
ctx.v = ctx.a.v * ctx.b.v; // repeat of what parser did--set return value
}
@Override
public void exitRule(AParser.addContext ctx) {
System.out.println("add "+ctx.a.v+" + "+ctx.b.v);
ctx.v = ctx.a.v + ctx.b.v;
}
}
public static void main(String[] args) throws Exception {
ALexer lexer = new ALexer(new ANTLRFileStream(args[0]));
CommonTokenStream tokens = new CommonTokenStream(lexer);
AParser p = new AParser(tokens);
p.setBuildParseTree(true);
// p.addParseListener(new Do(p));
ParserRuleContext<Token> t = p.s();
System.out.println("tree = "+t.toStringTree(p));
ParseTreeWalker walker = new ParseTreeWalker();
Do doer = new Do(p);
walker.walk(doer, t);
AParser.eContext ectx = (AParser.eContext)t.getChild(0);
System.out.println("result from tree walk = "+ ectx.v);
}
}

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@ -1,12 +1,13 @@
grammar U;
s : '{' stat* '}' ;
// if x then break else if y then return else break
// still ambig: if x then if y then break else break
stat: 'if' ID 'then' stat ('else' stat)?
| 'break'
| 'return'
;
INT : '0'..'9'+ ;
s @after {System.out.println($ctx.toStringTree(this));} : e EOF ;
e : e '.' ID
| e '.' 'this'
| '-' e
| e '*' e
| e ('+'|'-') e
| INT
| ID
;
ID : 'a'..'z'+ ;
WS : (' '|'\n')+ {skip();} ;
INT : '0'..'9'+ ;
WS : (' '|'\n') {skip();} ;