Land of Lisp

What You've Learned

This chapter demonstrated how to create DSLs in Lisp. You learned the following:

• When you need to do some weird programming for a very specific domain, Macros are a great solution. With them, you can create your own DSL.

• Often, it makes sense to first write a helper function for a macro (like print-tag), and then write a macro (like tag) to add improvements that only a macro can provide. These improvements usually involve being able to access the code with a clearer, and often safer, syntax.

• You can mix DSLs with regular Lisp code, which gives you a lot of power.

• DSLs are useful when you need to write very specific code—whether it’s code for a web page, code that draws a picture, or code that builds special game commands.