[kennytilton]

Was McCarthy even thinking of macros when he locked onto code as data? Or was he thinking code generation in pursuit of AI?Asking, do not know. I know macros are a great example of code=data, but I once had a ball using the AllegroStore CLOS database and a homebrewed DB synch layer to handle remote distribution and update of forms and the code to validate them in a clinical drug trial management context, where forms and their validation code are forever changing. Basically, an intractable software maintenance problem just disappeared. That's always fun. http://smuglispweeny.blogspot.com/2008/03/my-biggest-lisp-pr...

[dangerbird2]

He was not, macro libraries like defmacro and define-syntax were later addition to lisp. Well before formal macro systems were implemented, code-as-data was particularly useful for implementing the eval function in Lisp (the Lisp 1.5 implementation takes up less than a page), which greatly simplified the process of implementing compilers and interpreters.