Reimplementation of the Beta string rewriting engine originally written by Benny Brodda in Fortran and later on reimplemented by Kimmo Koskenniemi in Pascal and in C.
The input formalism follows the C version as documented in F. Karlsson and K. Koskenniemi, "Beta-ohjelma kielentutkimuksen apuvälineenä", Yliopistopaino, 1990. An English version of that manual is available here as a manual [[BETA: a tool for a linguist|https://github.com/koskenni/beta/betaref.md]].
This program was written from scratch in Python3 without any reference to the above mentioned predecessors.
This program is free software under the GPL 3 license. You can load beta.py by cloning the koskenni/beta directory in Github. If you only want the beta.py file (which is sufficien for many purposes) you may (use your browser or the wget program e.g. in Gnu/Linux, Unix or Mac iOS to) load it from:
https://raw.githubusercontent.com/koskenni/beta/master/beta.py
The program depends on a package "datrie" which must be installed on your system, see the Beta wiki for [[detailed instructions|https://github.com/koskenni/beta/wiki/datrie]].
- Version 0.1 - 2017-04-26: Initial release
- Version 0.1.1 2017-04-27: Set identifiers may now contain also "-" and "*", x parts in rules may nou start with a space
- Version 0.2 2017-10-17: Now even LIMITOR and BLANK implemented
- Version 0.3 - 2018-02-07: LIMITOR improved, tracing improved
- Version 0.3.2 - 2018-02-08: Char and state set names can now include #
- Version 0.3,3 - 2018-02-09: Validity of ch and st sets is checked; character and state names may now have more symbols in them; parenthesis comments now also for rules without condition or other params