"lexeme default" statements now allow the "forgiving" option in the
working branch. It's in the test suite and documented. I've lost track
of which commit, but the change should make it into the next developer's
release. -- jeffrey
On 01/09/2014 09:22 AM, Ruslan Shvedov wrote:
On Thu, Jan 9, 2014 at 6:01 PM, Jeffrey Kegler
<[email protected]
<mailto:[email protected]>> wrote:
I'll add "forgiving" to "lexeme default", as you suggest. I'm not
at all sure it's a good idea, but the UNIX/Perl tradition is that
you give the user the tools and let them decide. -- jeffrey
Great, thanks.
P.S. I've to admit that I can't see the use case yet, but I (hopefully
correct) read above that "longest acceptable tokens" behavior, a
motivation of amon's IRIF, is enabled by marking all tokens forgiving
and that will be done safely at a low cost once "cheap forgiving" is
implemented, hence the suggestion.
On 01/08/2014 10:37 PM, Ruslan Shvedov wrote:
Very useful feature, thanks a lot.
Can /forgiving/ adverb be added to /lexeme default/ so that an
application be able to mark all lexemes as (un)forgiving and then
set individual lexemes as forgiving or unforgiving as needed?
P.S. 2.079_007
<https://metacpan.org/release/JKEGL/Marpa-R2-2.079_007> built,
installed, and tested just fine for me on cygwin and windows with
5.14.2 and 5.18.1.
On Wed, Jan 8, 2014 at 9:25 AM, Jeffrey Kegler
<[email protected]
<mailto:[email protected]>> wrote:
I've uploaded a new developer's version, 2.079_007
<https://metacpan.org/release/JKEGL/Marpa-R2-2.079_007>, this
time with some clearly visible added value: forgiving
tokens. Forgiving tokens are tokens that are declared to be
exceptions from the usually rigid longest-tokens-match
discipline. The usual (and traditional) LTM discipline
insists that the token is the longest match at any point. If
the LTM token is not acceptable to the grammar, then the
parse fails.
A forgiving token declares itself to be an exception to the
LTM discipline. If a forgiving token is the longest match,
but it is rejected by G1, the rejection will be "forgiven"
and the SLIF will look for shorter tokens that it can accept.
I've uploaded as Github gists two examples that previously
were difficult lexing situations, redone using forgiving
tokens: one is Ruslan Zakirov's
<https://gist.github.com/jeffreykegler/8312534> and the other
is Peter Stuifzand's
<https://gist.github.com/jeffreykegler/8312524>. I have not
documented the forgiving adverb yet, but the syntax is easy
enough to figure out from the two examples.
--
You received this message because you are subscribed to the
Google Groups "marpa parser" group.
To unsubscribe from this group and stop receiving emails from
it, send an email to
[email protected]
<mailto:marpa-parser%[email protected]>.
For more options, visit https://groups.google.com/groups/opt_out.
--
You received this message because you are subscribed to the
Google Groups "marpa parser" group.
To unsubscribe from this group and stop receiving emails from it,
send an email to [email protected]
<mailto:[email protected]>.
For more options, visit https://groups.google.com/groups/opt_out.
--
You received this message because you are subscribed to the Google
Groups "marpa parser" group.
To unsubscribe from this group and stop receiving emails from it,
send an email to [email protected]
<mailto:marpa-parser%[email protected]>.
For more options, visit https://groups.google.com/groups/opt_out.
--
You received this message because you are subscribed to the Google
Groups "marpa parser" group.
To unsubscribe from this group and stop receiving emails from it, send
an email to [email protected].
For more options, visit https://groups.google.com/groups/opt_out.
--
You received this message because you are subscribed to the Google Groups "marpa
parser" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to [email protected].
For more options, visit https://groups.google.com/groups/opt_out.
