Scalabha

Author: Jason Baldridge (jasonbaldridge@gmail.com)

Introduction

This is to be a package for helping teach Computational Linguistics using Scala. No aspirations in particular to be like NLTK, just something to provide some basic functionality and a build structure for students.

It's called Scalabha because "bha" is a Proto-Indo-European root that is connected with language and speech.

Requirements

• Version 1.6 of the Java 2 SDK (http://java.sun.com)

Configuring your environment variables

The easiest thing to do is to set the environment variables JAVA_HOME and SCALABHA_DIR to the relevant locations on your system. Set JAVA_HOME to match the top level directory containing the Java installation you want to use.

For example, on Windows:

C:\> set JAVA_HOME=C:\Program Files\jdk1.5.0_04

or on Unix:

(csh)
% setenv JAVA_HOME /usr/local/java

(ksh, bash)	
> export JAVA_HOME=/usr/java

On Windows, to get these settings to persist, it's actually easiest to set your environment variables through the System Properties from the Control Panel. For example, under WinXP, go to Control Panel, click on System Properties, choose the Advanced tab, click on Environment Variables, and add your settings in the User variables area.

Next, likewise set SCALABHA_DIR to be the top level directory where you unzipped the Scalabha download. In Unix, type pwd in the directory where this file is and use the path given to you by the shell as SCALABHA_DIR. You can set this in the same manner as for JAVA_HOME above.

Next, add the directory SCALABHA_DIR/bin to your path. For example, you can set the path in your .bashrc file as follows:

export PATH=$PATH:$SCALABHA_DIR/bin

Once you have taken care of these three things, you should be able to build and use the Scalabha Library.

Note: Spaces are allowed in JAVA_HOME but not in SCALABHA_DIR. To set an environment variable with spaces in it, you need to put quotes around the value when on Unix, but you must NOT do this when under Windows.

Building the system from source

Scalabha uses SBT (Simple Build Tool) with a standard directory structure. To build Scalabha, type (in the $SCALABHA_DIR directory):

$ scalabha build update compile

This will compile the source files and put them in ./target/classes. If this is your first time running it, you will see messages about Scala being downloaded -- this is fine and expected. Once that is over, the Scalabha code will be compiled.

To try out other build targets, do:

$ scalabha build

This will drop you into the SBT interface. To see the actions that are possible, hit the TAB key. (In general, you can do auto-completion on any command prefix in SBT, hurrah!)

Documentation for SBT is at https://github.com/harrah/xsbt/wiki

Note: if you have SBT 0.11.1 already installed on your system, you can also just call it directly with "sbt" in SCALABHA_DIR.

Trying it out

Assuming you have completed all of the above steps, including running the "compile" action in SBT, you should now be able to try out some examples, to be added.

Now what?

One purpose of this package is to allow people to easily build a jar of their own without needing anything other than the command line and Java. You should be able to adapt the SBT build to your own project and start creating your own packages based on these fairly straightforwardly. You'll want to:

• Change $SCALABHA_DIR/build.sbt properties and configurations to be appropriate for your project. If you need to specify new managed dependencies, you can do so easily in that file (see SBT documentation for details). If you prefer to add dependencies manually, just add them to $SCALABHA_DIR/lib and they'll get picked up without any fuss.

• Change $SCALABHA_DIR/bin to be an executable of your choice, named for your project, and adapt as necessary (including changing $SCALABHA to your project name, etc).

Good luck!

Questions or suggestions?

Email Jason Baldridge: jasonbaldridge@gmail.com

Or, create an issue: https://github.com/utcompling/Scalabha/issues