Conversions to Pest of 0-repetition ABNF rules fail
eggyal opened this issue · 1 comments
Some ABNF rules, such as the path-empty
rule defined in RFC3896§3.3, resolve to the empty string via repetitions of exactly 0
occurrences:
path-empty = 0<pchar>
Alas, repetitions of exactly 0
occurrences are (currently) invalid in pest.
Perhaps abnf_to_pest
could check for such a condition, then output an empty property value as described in "A thoughtful introduction to the pest parser" under Writing the grammar:
Section names and property keys must not be empty, but property values may be empty (as in the line
ip=
above).
Edit: Realised that the above refers to the sample INI format being parsed in that example, not the grammar of Pest itself. I guess support for 0-repetitions will be required in Pest?
Yeah, we could make that work. I'm sure there's a way to ask pest to match the empty string