Tag: gem

Categories
computer

Prolog for Ruby (ruby-prolog) Updated, Hits v1.0.1

After a long period of inactivity I’ve updated the F/OSS ruby-prolog gem! It’s been updated for ruby 2.0.0, bundler, and minitest, and released as v1.0.1!

ruby-prolog allows you to solve complex logic problems on the fly using a dynamic, Prolog-like DSL. Basic use is encompassed by stating basic facts using your data, defining rules, and then asking questions. Why is this cool? Because ruby-prolog allows you to leave your normal object-oriented vortex on demand and step into the alternate reality of declarative languages.

With ruby-prolog:

  • There are no classes.
  • There are no functions.
  • There are no variables.
  • There are no control flow statements.

You can use all these wonder things — it’s still Ruby after all — but they’re not needed, and mainly useful for getting data and results into/out of the interpreter. Prolog still tends to be favored heavily in artificial intelligence and theorem proving applications and is still relevant to computer science curricula as well, so I hope this updated release proves useful to the Ruby community.

Check out a simple ACL enforcement example or, for the daring, the ruby-prolog solution to the Tower’s of Hanoi problem!

 

Categories
computer

Installing The MySQL Ruby Gem When Using The Official MySQL .dmg

If you installed MySQL using the official .dmg package provided by MySQL AB/Sun and are trying to install the native MySQL gem, you’ll need to pass a bunch of flags to the gem install process to get the thing to compile. Try this..

sudo gem install mysql — –with-mysql-config=/usr/local/mysql/bin/mysql_config

..if you still have issues (check your /opt/local/lib/ruby/gems/<ruby_ver>/gems/mysql-<gem_ver>/mkmf.log file), try this instead..

sudo gem install mysql — –with-mysql-dir=/usr/local/mysql –with-mysql-include=/usr/local/mysql/include/ –with-mysql-lib=/usr/local/mysql/lib/ –with-mysql-config=/usr/local/mysql/bin/mysql_config

Run `sudo gem install mysql` and definitely recheck the log file again as the gem install process sometimes reports false positives even if native components fail to install.