November 2012 Archives

Marpa::R2 is now in full release

[ This is cross-posted from the new home of the Ocean of Awareness blog. ]

Marpa::R2 is now in full, official release. For those new to this blog, Marpa::R2 is an efficient, practical general BNF parser, targeted at applications too complex for regular expressions. Marpa::R2 is based on

A Marpa tutorial: iterative parser development

[ This is cross-posted from the new home of the Ocean of Awareness blog. ]

This post describes a manageable way to write a complex parser, a little bit at a time, testing as you go. This tutorial will "iterate" a parser through one development step. As the first iteration step, we will use the example parser from ="http://jeffreykegler.github.com/Ocean-of-Awareness-blog/individual/2012/11/patter…

A Marpa tutorial: pattern searches

[ This is cross-posted from the new home of the Ocean of Awareness blog. ]

We use regular expressions for pattern searching these days. But what if your search target is not a regular expression? In this post I will show how to use Marpa to search text files for arbitrary context-free expressions.

This tutorial builds on earlier tutorials. It is possible to simply dive into it, but it may be easi…

A grammar that exemplifies, describes and parses itself

[ This is cross-posted from the Ocean of Awareness blog. ]

I've written a grammar in Marpa's new BNF interface, to parse Marpa's new BNF interface. In the 70's, when I learned parsing theory, this was a very fashionable thing to do, perhaps because yacc had done it, in Appendix B of the original 1975 paper. By 1979, Hoftstadter's book Godel-Escher-Bach (GEB) was out, and the…

About Jeffrey Kegler

user-pic I blog about Marpa, my parsing algorithm, and other things of interest to techies.