tour eevo

;;;; tour eevo

;;; Hello World

;; Display hello world on the screen

; good programmers comment their code
println "Hello World"

;;; Numbers

; numbers can be integers, decimals, or fractions
def x 12
def y 6
x + y ;=> 18
y - x ;=> -6
y / x ;=> 1/2

def z (x * (y - 3)) ;=> 36
z - 5.0 ;=> 31.0
z * 1/3 ;=> 12

;;; Integers

5
1234
; scientific notation for integers
4e3 ;=> 4000

;;; Decimals

0.3
3.14
.13

;;; Fractions

1/3 ;=> 1/3
6/4 ;=> 3/2
4/2 ;=> 2

;;; Booleans

True
False ;=> Nil
Nil

;;; Variables

def x 4                           ; integers
def pi-approx 3.14                ; decimals
def pi-better 22/7                ; ratios
def hello_world "hello world"     ; strings
def func 'sum                     ; symbols
def active? True                  ; boolean
def a Nil                         ; nil, empty
def ages [23 47 12 59]            ; lists
def prices [7.50 8 3.25 ... 10]   ; improper lists
def people { bob: 23  alice: 47 } ; records