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|
options {
language="Cpp";
}
{
#include <iostream>
}
class Rewrite extends Lexer;
//protected
START
options {
ignore=WS_;
}
: id:ID ":="! '('! expr:EXPR ')'!
{
// can access text matched for any rule
std::cout << "found " << id->getText() << "," << expr->getText() << std::endl;
// text will be ID+EXPR minus whitespace
}
;
protected
ID : ( let:LETTER {std::cout << "letter " << let->getText() << std::endl;} )+
;
protected
LETTER
: 'a'..'z'
{
std::string s = $getText; // get access text of this rule
// $setText(s.toUpperCase()); // can reset it too
$setText(s); // can reset it too
}
;
protected
EXPR: i:INT! // don't include, but i->getText() has access
{$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(ANTLR_USE_NAMESPACE(antlr)Token::SKIP);} // way to set token type
;
|
