Looking for a DSL idea

time to read 2 min | 249 words

I need to start writing the second part of the book soon. This one is supposed to take a DSL implementation through all the interesting stages that I would like to cover. However, I am not sure yet what the subject of the DSL will be.
I need something that has enough scope to last for about a hundred pages, complex enough to expose usual problem when writing DSL and not tied to a specific domain so strongly that it would be hard to outsiders to grasp.

I am also interested in knowing what kinds of patterns and problems you would like me to cover.

My current line of thinking is to build several DSL around the backend of an online store. That domain should be fairly familiar to all, and it is rich enough to offer a lot of things to discuss. It is also a good place to discuss several types of DSL.

I was thinking of the following DSL:

  • Message routing / dispatch DSL
  • Order processing DSL
  • Then we will extend that to be a generic rule engine DSL
  • Perhaps creating a testing DSL for those DSL or for the domain itself

The main problem that I have now is that building those DSL is very simple, I don't think that it would be enough to cover everything the we need to build DSL. In that light, I am looking for either more ideas or challenges on the use of the above mentioned DSL.