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Re: [Marpa::R2] More Help With Grammar

by Jeffrey Kegler (Hermit)
on Nov 17, 2013 at 02:57 UTC ( #1062960=note: print w/replies, xml ) Need Help??

in reply to [Marpa::R2] More Help With Grammar

The problem you are having with multiple lines was caused by defining your file as only containing a single line. Here's what you need:

:default ::= action => [values] :start ::= Definitions :discard ~ ws Definitions ::= Definition + Definition ::= Alias <new line>

As for the backslash'd newlines, to treat them as horizontal space, you want something like:

ws ~ <ws element> + <ws element> ~ [\s] <ws element> ~ backslash [\n] <backslash> ~ '\'

I did test both of these with your multi-line example and they seem to work. The Sudoer's format is newline-sensitive -- it treats horizontal and vertical whitespace differently. You'll probably need to nail down exactly where newlines are OK according to the spec, before you're 100% compliant. Marpa has a mailing list, btw, where expert users hang out. Several of the people on the group have more experience with parsers for this kind of file than I have. You might consider joining up.

I hope this helps.

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Re^2: [Marpa::R2] More Help With Grammar (ABNF to Marpa/SLIF)
by Anonymous Monk on Nov 17, 2013 at 03:21 UTC

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