[antlr-interest] Parsing this ambiguous grammar

[Gerald Gutierrez]

On Fri, Jan 27, 2012 at 12:25, Jim Idle <jimi at temporal-wave.com> wrote:
> However, I am taking your grammar at its word that A B or C must always be
> PITCH. I also assume that you cannot have ' ' in your ID or you have no
> way at all to disambiguate except for context. However, this may come from
> a hand crafted context sensitive parser made by a musician not a
> programmer and so you will have to jump through hoops in the parser to try
> and make it work.

The real goal here is to parse an RTTTL file by embodying the entirety
of the RTTTL file format in ANTLR. The RTTTL spec was developed by
Nokia and is described here:

http://www.csoft.co.uk/ringtones/rtttl_rtx.htm

An example is:

Entertainer:d=4,o=5,b=200:8d,8d#,8e,c6,8e,c6

It starts with a name, which can have any displayable character. A, B,
C do not have to be the pitch. They can be the name as well.

Given what has been said, it is not possible to cleanly describe RTTTL
in ANTLR. We (me & my friend who originated this) haven't found a
solution and a clean solution doesn't seem forthcoming.

Which means to me that we're back to regular expressions. Best way to
go given the situation?


Gerald.