[antlr-interest] Undocumented error message
Darien A Hager
darien at technofovea.com
Sun Oct 11 14:58:22 PDT 2009
William B. Clodius wrote:
> First, what kind of parameters are expected for a rule in ANTLR and
> how do I define them?
This may or may not answer your question, but the following example
should give a similar error.
________________________________________
parser grammar temp;
tokens{
MYTOK;
}
foo [Tshirt x]
: msg=bar[x]
{
System.out.println(msg);
}
;
bar returns [String message]
: MYTOK {
message = "I went and parsed stuff and all I got was this lousy
T-shirt that says "+x.getFrontText();
}
;
________________________________________
What this flawed grammar is intended to do is pass an object of type
Thingy in when executing the rule "foo". And then every time the rule
"foo" goes and calls rule "bar", "bar" will also have access to that
object. To fix it, I need to add an input parameter (really, a
positional function argument) to the final rule:
________________________________________
bar [Tshirt x] returns [String message]
________________________________________
At least for me, the error message numbers mean the line/column where I
tried to put bar[x] while bar was unable to accept any arguments.
--Darien
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