[antlr-interest] newbie problem)reference to rewrite element name without reference on left of ->.
Randall R Schulz
rschulz at sonic.net
Mon Jul 9 16:09:52 PDT 2007
On Monday 09 July 2007 16:04, ali azimi wrote:
> Hi,
>
> I have a problem regarding rewrite error messages. The Rule1
> produces Error1 when I try to generate code from it. But when I
> enclose the parser grammar(before ->) in parenthesis (Rule2), there
> is no error message.
>
>
> Why is that?
Operator precedence.
The rewrite rule operator, ->, binds more tightly than alternation
("or" / vertical bar). In your Rule1 the first two alternatives have no
explicit rewrite at all; only the last one, "timeridentifier" has an
explicit rewrite action.
> ...
>
> Al
Inter-caps or even underscores would help grammar readability, too.
Randall Schulz
More information about the antlr-interest
mailing list