I just took a second look at this one
GlobalPList plist4 { Pat n8000000g0000008; #KEEP# } }
Ouch! The solution in the face of stuff like this may be to not treat
comments at the lexical level, but at the G1 level. That is, treat the
'#', ',', tags, etc. as lexemes and parse comments as if they were
statements. In your situation, that seems in effect to be the case.
Your comments seem to have more structure and variety than some of the
"statements". They are not just whitespace equivalents.
At the G1 level you can use rule "rank" adverb
(https://metacpan.org/pod/distribution/Marpa-R2/pod/Scanless/DSL.pod#rank),
Marpa can help with the internal semantics of the comments. etc.
I notice, by the way, that my documentation of the "rank" adverb could
be improved.
-- jeffrey
On 05/09/2014 12:09 PM, [email protected] wrote:
You have the right idea. Unfortunately, I do not get to dictate the
syntax of this file I get to parse and there is considerable ambiguity
in comments. There are essentially three forms of a comment. Two
forms of this comment include information I need to parse. One form
(non-information comment) does not contain useful information.
1) embedded base number --> Matches OptEmbeddedBase --> Actual
information I need. Discernable from a non-information comment by
it's location immediately after the opening of a pattern list brace
and that if must contain '#base=<list>', where <list> is a comma
delimited list of integers.
2) tag string --> Matches TagStr --> Again, information I need.
Discernable from a non-information comment by location after a pattern
declaration and by the fact that it is bookended by '#' symbols can
can only contain a comma delimited list of word (\w) characters.
Technically, whitespace is not allowed inside these strings either. I
figured I'd sort that out once I had it matching as is.
3) Non information comment -> Matches COMMENT --> Can be discarded.
This is any comment that does not match one of the first two forms.
Hopefully that's helpful. When you say that you'd 'simply say that in
the grammar', I'm confused. Is this not what I'm saying in the
grammar in the TagStr rule by setting '#' characters before and after
the TagList rule? Is there a better way to resolve this ambiguity?
On Friday, May 9, 2014 11:46:16 AM UTC-7, Jeffrey Kegler wrote:
Trying to get the idea, is it that tags use '#' as a delimiter,
much in
the same way that strings use quotes? And that's it's a comment if
there's a '#' that is not matched before the newline? That is,
that in
Pat n2000000g0000002; #HOT# # Not so hot
"#HOT#" is a tag, and "# Not so hot" is a comment?
If that's the case, I'd simply say that in the grammar. I'd give
more
detail, but I'm not 100% clear on the intent at this point.
-- jeffrey
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