Archive for June 24th, 2009
Developing a Complex External DSL. Part 1.
June 24th, 2009
The use of a domain-specific language, or DSL, is becoming a realistic and even necessary solution for software developers on all sorts of software development projects. You’ve heard about DSLs, and you may know that DSLs are divided into a few different styles, internal and external. But what is an internal DSL and external DSL? When would you decide to use one or the other? And, primarily, how would you go about developing a complex external DSL? This article answers these questions, with a focus on developing a complex external DSL.
Defining Domain-Specific Language
A domain-specific language (DSL) is a computer language that is developed to specialize in addressing the needs of a given problem domain. The domain itself could be many things. It could be specific to an industry, such as insurance, education, aerospace, medicine, etc., or to a technology or methodology, such as JEE, .NET, database, services, messaging, architecture, or domain-driven design.
The reason I would develop a DSL is to make dealing with a set of challenges in a domain I am working in more elegant and easier to deal with. That’s because the language I create will be just what I need to address my unique set of challenges, and no more than that. And of course, if I provide my language for others to use it may have to broaden a bit to address what they need, but still nothing more. The effort has the goal of making it feel more natural to use the DSL than to use a general purpose programming language or some other non-targeted tool.
