search

shiryu92kmp / ouspg

Automatically exported from code.google.com/p/ouspg
1 stars 0 forks source link

- except-symbol is not implemented #75

Closed GoogleCodeExporter closed 9 years ago

GoogleCodeExporter commented 9 years ago 
- except-symbol is not working in production rules

Original issue reported on code.google.com by sachinsh...@gmail.com on 21 May 2012 at 1:46

GoogleCodeExporter commented 9 years ago 
That would be possible to add for simple subsets, like regexps, but context 
free languages aren't closed under difference, so this cannot be implemented in 
blab as it is.

Original comment by aohelin on 21 May 2012 at 2:43