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|
class Rewrite extends Lexer;
protected
START
options {
ignore=WS;
}
: id:ID ":="! '('! expr:EXPR ')'!
{
// can access text matched for any rule
System.out.println("found "+id.getText()+","+expr.getText());
// text will be ID+EXPR minus whitespace
}
;
protected
ID : ( let:LETTER {System.out.println("letter "+let.getText());} )+
;
protected
LETTER
: 'a'..'z'
{
String s = $getText; // get access text of this rule
$setText(s.toUpperCase()); // can reset it too
}
;
protected
EXPR: i:INT! // don't include, but i.getText() has access
{$setText(i.getText());} // effect is if no "!" and no "i:"
| ID
;
protected
INT : ('0'..'9')+
;
// what if ! on rule itself and invoker had !...should
// rule return anything in the token to the invoker? NO!
// make sure 'if' is in the right spot
// What about no ! on caller but ! on called rule?
protected
WS! : ( ' ' // whitespace not saved
| '\t'
| '\n' {newline();}
)+
{$setType(Token.SKIP);} // way to set token type
;
|
