gmichokostas

Hofstadter on Lisp

In the mid-80s, while reading through my roommate's collection of Scientific American back issues, I encountered this introduction to Lisp written by Douglas Hofstadter. I found it very charming at the time, and provide it here (somewhat illegally) for the edification of a new generation of Lispers.

In a testament to the timelessness of Lisp, you can still run all the examples below in emacs if you install these aliases:

(defalias 'plus #'+)
(defalias 'quotient #'/)
(defalias 'times #'*)
(defalias 'difference #'-)

gmichokostas

require 'pg'
PGDB = PG.connect(host: '/tmp', dbname: 'mydb')
PGDB.type_map_for_results = PG::BasicTypeMapForResults.new(PGDB)

class Hash
  def symbolize_keys
    inject({}) { |m, kv| v = kv[1];
      m[kv[0].to_sym] = v.is_a?(Hash) ? v.symbolize_keys : v; m }
  end
end