Short history of Lisp

1
Short history of Lisp

• Lisp appeared first in 1958
• Linked lists in Lisp
• Several dialects of Lisp appeared Common Lisp,
  Emacs Lisp, Scheme
• In 1988, after the inclusion of CLOS, Common Lisp
  became the first standardized object oriented
  language
• Several commercial implementations of Lisp
  appeared on the market Allegro CL, LispWorks,
  Macintosh Common Lisp
• Today Common Lisp is a multi-paradigm language
  functional, reflective, object-oriented

2
What made Lisp different

• conditionals (at that time Fortran only had a
  conditional GOTO)?
• a function data type functions can be passed as
  arguments, returned from other functions, etc.
• recursion
• variables values have a type, not variables
• garbage collection
• code is data, data is code

3
Allegro CL
4
LispWorks
5
What makes Lisp different today

• compact and easy to read code
• incremental development / fast prototyping
• macros
• reflection
• error handling

6
Examples

• (defun funny-sort(my-string)
• (stable-sort my-string '(lambda(a b)(if (
  (random 2) 0) t nil))))
• (defun check-sort(my-string)
• (do ((end nil) (counter 0 (1 counter)))
• ((or end ( counter 1000000)) (print
  counter))
• (when (string-equal my-string (funny-sort
  (copy-seq my-string)))
• (setf end t)
• (print "FOUND A MATCH !!!"))))

7
Macros in action

• the sum of the even integers from 1 to 10
• (loop for i from 1 to 10 when (evenp i) sum i)
• (setf numbers '(3 1 34 0 23 94 5 6 7 234 2))
• print a message if all numbers in numbers
  are even
• (if (loop for n in numbers always (evenp n))
• (print "All numbers even."))

8
Macros in action

• print the smallest number in numbers
• (loop for i in numbers minimizing i into min
  finally (print min))
• convert the numbers to words
• (setf numbers
• (loop for i in numbers collect (format nil
  "r" i)))
• ("three" "one" "thirty-four" "zero"
  "twenty-three" "ninety-four" "five" "six" "seven"
  "two hundred thirty-four" ...)

9

• "Lisp has jokingly been called "the most
  intelligent way to misuse computer". I think that
  description is a great compliment because it
  transmits the full flavor of liberation it has
  assisted a number of our most gifted fellow
  humans in thinking previously impossible
  thoughts."
• - Edsger Dijkstra
• "Don't worry about what anybody else is going to
  do. The best way to predict the future is to
  invent it."
• - Alan Kay