Alf brings the relational algebra both in Shell and in Ruby. In Shell, because manipulating any relation-like data source should be as straightforward as a one-liner. In Ruby, because I've never understood why programming languages provide data structures like arrays, hashes, sets, trees and graphs but not _relations_... Let's stop the segregation ;-)

This project implements an abstract SQL compiler for Alf expressions

Provides the parser + compiler infrastructure for the Gisele process modeling language.

Predicate provides a simple class and processors to encode and manipulate (tuple) predicates