For what kind of problems do you write a DSL?

Question

I'm just curious about Domain-Specific Languages. I have seen them several times in articles, and it seems that they can be used outside assurance or bank data definition problems.

So I come to SO to have some concrete input.

Did you ever use a DSL? Write one. If yes, what's it feel like?

Do you think one of your projects could be better (more productive, more maintainable, ...) with a DSL?

Edit : I'm sorry to put this after, but i was meanning a specific DSL that you wrote yourself. It's exclude Tex, HTML, Make , SQL. I fact, the question was more : "writing a DSL"

Answer 1

I'd say there is quite a continuum between very readable API as a weak form of DSL (what some call a fluent interface), an internal DSL as something in between and a full grammar-defined external DSL on the other end.

The weakest form is something that I kind of always try to achieve (i.e. make the API as closest to the problem domain as possible). A DSL on the other end of the continuum makes a lot of sense if non-programmers will be using the software, e.g. to enter data.

And with a framework like Xtext even a full external DSL, including an editor supporting syntax coloring and error checking is much easier to implement than it might initially seem.