Episode 120: OCL with Anneke Kleppe

Creation

Anneke Kleppe shares the inspirations behind the creation of the Object Constraint Language (OCL), highlighting influences from programming languages like Eiffel and Smalltalk, as well as IBM's business process modeling. She emphasizes the need for a language that allows IT professionals to express complex business constraints more efficiently 1. OCL was developed to address the limitations of class diagrams in expressing static constraints, such as ensuring a person's age is not less than zero 2.

We created a language and of course all type of background stuff like set theory from mathematics and things like that.

--- Anneke Kleppe

Anneke worked alongside her colleague Jos Werner, integrating various elements to form OCL, which ultimately differed from its inspirations 1.

   

Future

Looking ahead, Anneke envisions a future for the concepts introduced by OCL, even if the language itself may not endure. She sees its influence in modern programming languages like Java and C#, where simpler ways of expressing loops and constraints are evident 3. Despite the lack of demand for OCL in UML tools, she believes its principles remain valuable for building robust models.

I see a large future in the concepts that we introduced.

--- Anneke Kleppe

Anneke expresses surprise at the limited tool support for OCL, attributing it to a lack of client demand, yet she remains optimistic about its potential applications 3.