December 2012 Archives

A self-parsing and self-lexing grammar

[ This is cross-posted from the new home of the Ocean of Awareness blog. ] a previous post, I showed a self-parsing grammar, written in Marpa's new BNF interface. That grammar was in a tradition going back to the 70's. Following the tradition, I cheated a bit. That grammar required, but did not include, a lexer to make a prepass over its inp…

Smart whitespace and the Ruby Slippers

Scannerless parsing

new home of the Ocean of Awareness blog. ]

I've been working on a "scannerless" Marpa interface. "Scannerless" means that the user does not need to write a separate lexer -- the lexer (scanner) is included in the parser. One of my working examples is the synopsis from the main Marpa::R2 POD page, rewritten to d…

About Jeffrey Kegler

user-pic I blog about Perl, with a focus on parsing and Marpa, my parsing algorithm based on Jay Earley's.