Introduction
In typical software development projects the Object Constraint Language (OCL) can be used for the specification of object-oriented software. The OCL is a formal language to express constraints. It is based on predicate logic.

Conventional integrated development environments (IDEs) provide a wide range of func-tionality to programmers, such as: editor with syntax highlighting, integrated compiler and debugger, wizards, etc. Many of these IDEs can be extended by 3rd party tools, which can be integrated homogenously.

The goal of this work is the development of a tool for the Eclipse platform that can be used for writing and maintaining OCL expressions. The OCL language is used to specify pre-, post-conditions and invariants for interfaces and classes (in a Design by Contract style). The tool also contains a parser to check the syntactical and semantical correctness (better known as typechecking) of the written OCL expressions.

Some Technical Background
The Dresden OCL Toolkit is used for parsing the OCL statements. This toolkit supports only OCL version 1.3, which doesn't allow to fully specify the location of a context. So the Dresden OCL Toolkit was modified to support package structures (introduced in OCL 1.4). This is the only modification to the toolkit's sources.

The model information is extracted from a Eclipse Java project using Eclipse's Java development tooling ( JDT). The extracted model information is structured in a form that the Dresden OCL Toolkit can use it to check the semantical correctness of the written OCL statements.

Status
Second Alpha version (released 2004-10-06). Currently the OCL editor is only working with Eclipse 3.0. Eclipse 2.1 support will follow soon.

	SourceForge project summary
	The OCL Editor project is hosted on SourceForge and we make extensive use of its services for our needs.