• tags :: Lispprogramming languagesDialDial implementation

When implementing a Lisp in particular, the goal should be to express the totality of the Lisp with only a minimal set of implementation language code. For example, it wouldn't make a lot of sense to implement when in the source language (say, C) when, if if is implemented, it could be expressed as if¹

Primitives include but are not limited to:

• Basic data types

• Any arithmetic

• lambda or equivalent

  • if

• cond

• list

• apply

• defmacro

• quote

The rest of a Lisp is simply library code, which can be expressed using all of the above.

Footnotes

¹In fact, it could be expressed like this:

; a copy of emacs's own =when= definition
(defmacro my-when (condition &rest body)
  (list 'if condition (cons 'progn body)))

(macroexpand '(my-when t
         (message "hello world I did it")))