Ella - An interpreter for the EllaScript programming language

About
=====

The EllaScript language is a scripting language intended to be used for
scripting SQL.

It's language structure is designed as being a superset of SQL, so that (in
theory) every existing SQL script (written in a supported SQL dialect) should
be a valid EllaScript program.

In addition to SQL EllaScript provides all the language elements one would
expect from a general purpose scripting language: variables, control
statements, (higher order) functions, objects, etc.

The language can be described as a prototype-based object-oriented language
inspired by Smalltalk, Self, JavaScript and IO.

The syntax and semantics of the language are designed with the goal of being
easy to learn (which is difficult at the moment because of the lack of
documentation) and easy to use.

It runs on the Java Virtual Machine and allows to use Java classes and objects
directly from EllaScript programs providing access to the full potential of the
Java ecosystem where the Ella runtime library lacks functionality.

Supported Database Systems
==========================

Ella uses JDBC for interaction with database systems. It supports every database
system as long as it's SQL syntax is compatible with the SQL2003 standard.
It has special support for MySQL, PostgreSQL and Oracle, supporting some of their
syntactic specialties.

Usage
=====

This EllaScript interpreter requires a Java 6 Runtime Environment to run.
It was tested with the Sun JDK/JRE 1.6.0 only.

Unix/Linux
----------

A shell script, called "ella", for running the interpreter can be found
in the "bin" directory.

This defaults to starting in interactive mode when no filename is given
and standard input is a TTY.

Running "ella -h" gives a help message.

Other Systems
-------------

The Ella interpreter can also be run directly by executing the provided
JAR file, "ella-0.1-SNAPSHOT.jar", to be found in the "libexec" directory
of the distribution.

This way, when no filename is given, the script to be run is read from
standard input. Interactive mode has to be activated explicitly via the
"-i" command line switch.

Running "java -jar ella-0.1-SNAPSHOT.jar -h" gives a help message.

Project Layout
==============

The project uses the Maven 2 build system and follows the standard project
layout closely.

bin/		Unix shell scripts to invoke Ella from the build directory.
maven/		Contains a local maven repository holding dependencies
		not found in public repositories. Contains for example the
		bundled oracle JDBC driver.
src/		The project sources in the standard maven format.
src/config/	Some example databse connection properties files.
test/		Ad-hoc test scripts.
test/ng/	Test scripts used in unit tests.