There are different forms of programming

• Functional Programming
  • Programs are constructed by applying and composing functions
  • Stateless (no side-effect)
  • Out-of-order execution, deterministic, concurrency
  • Lisp is one of them

Datas

• Numbers (numbers, what else do you expect)

• Symbol (any sequence of letters, digits, and permissible special character that is not a number)

• List: represented within parenthesis

  (1,2,3,4,5)

  (1,b,c,e3,7) ← list can contains different types of information

  (1, 2, (3, 4), 5) ← can also do nested list

  Internally uses a linked list to represent

  

  

Predicate

• Answer true or false

• <, > , =

  (< 2 1) compares to see if 2 is less than 1, returns nil

Functions

• (func arg1, arg2 ...)
• Returns result with input
• Can compose functions together like (+ 1 (expt 2 4)) ← add one to 2^4
• To define function

(defun add1 (x) (+ 1 x))
(add1 5) 
6

Variables

(setq temp '(1 2 3 4 5))
;;         ^ the single quote will make lisp treat (1,2,3,4,5) as literal ;;

Control flow

There are 2 kinds of while loops here, iterate through the loop and decremental loop