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|
// This file is part of PyANTLR. See LICENSE.txt for license
// details..........Copyright (C) Wolfgang Haefelinger, 2004.
//
// $Id$
options {
language=Python;
}
class treewalk_p extends Parser;
options {
codeGenMakeSwitchThreshold = 3;
codeGenBitsetTestThreshold = 4;
buildAST=true;
}
block
: LCURLY^ ( statement )* RCURLY!
;
statement
: expr SEMI!
| "if"^ LPAREN! expr RPAREN! statement
( "else"! statement )?
| "while"^ LPAREN! expr RPAREN! statement
|! b:block { statement_AST = b_AST; }
// do some manual tree returning
;
expr: assignExpr
;
assignExpr
: aexpr (ASSIGN^ assignExpr)?
;
aexpr
: mexpr (PLUS^ mexpr)*
;
mexpr
: atom (STAR^ atom)*
;
atom: ID
| INT
;
class treewalk_w extends TreeParser;
block
: #( LCURLY ( stat )+ )
;
stat: #("if" expr stat (stat)?)
| #("while" expr stat)
| expr
| block
;
expr: #(ASSIGN expr expr) {print "found assign" }
| #(PLUS expr expr) {print "found +" }
| #(STAR expr expr) {print "found *" }
| a:ID {print "found ID " ,a.getText() }
| b:INT {print "found INT ",b.getText() }
;
class treewalk_l extends Lexer;
WS : (' '
| '\t'
| '\n'
| '\r')
{ _ttype = SKIP; }
;
LPAREN: '('
;
RPAREN: ')'
;
LCURLY: '{'
;
RCURLY: '}'
;
STAR: '*'
;
PLUS: '+'
;
ASSIGN
: '='
;
SEMI: ';'
;
COMMA
: ','
;
protected
ESC : '\\'
( 'n'
| 'r'
| 't'
| 'b'
| 'f'
| '"'
| '\''
| '\\'
| ('0'..'3') ( DIGIT (DIGIT)? )?
| ('4'..'7') (DIGIT)?
)
;
protected
DIGIT
: '0'..'9'
;
INT : (DIGIT)+
;
ID : ('a'..'z'|'A'..'Z'|'_') ('a'..'z'|'A'..'Z'|'_'|'0'..'9')*
{
try:
i = literals[self.getText()]
_ttype = i;
except:
pass
}
;
|
