Jade

Elixir Guide

Variables & Types

# Types
1       # Integer
0x1F
0b01
0o77
1.0     # Float (64 bit precision)
1.0e10
true    # Boolean
:atom   # Atom / Symbol
"str"   # String
[1, 2]  # List
{1, 2}  # Tuple
 
# String interpolation
string = "world"
"hello #{string}"
  • Atoms
    • Atoms (:hello) - also called symbols - is a constant whose value is its own name
    • They are usually used to represent the state of an operation (:ok, :error)
    • The booleans true and false along with nil are atoms. Elixir allows users to not prepend : to these
  • Strings
    • Are UTF-8 based
    • Interpolation allows any datatype
    • Represented internally by contiguous sequences of bytes known as binaries.
    • To get the byte amount, use byte_size and to get the actual string length, use String.length

Operators

# Relational operators
:atom == :atom  # true
1 != 1
1 < 2
2 > 1
1 <= 1
1 >= 1
 
# Strict comparison
1 == 1.0   # true
1 === 1.0  # false
 
# Logical operators
true or true    
true and false
not true
 
# Additional nil-supported logical operators
1 || true
nil && true
!nil
 
# Concatenation
"hello" <> "world"
  • or and and are short-circuit operators
  • false and nil are considered falsy, everything else, even "", 0 are truthy
  • Comparison operators perform structural comparison and not the semantic sort

Functions

# Function calling
div(10, 2)
div 10, 2  # Parentheses not required

Collections

# Lists
list = [1, 2, true, 3]
[1, 2] ++ [3, 4]  # Concatenation
[1, 2] -- [1]     # De-concatenation
hd(list)   # 1
tl(list)   # [2, true, 3]
[11, 12, 13]  # ~c"\v\f\r"
 
# Tuples
{:ok, "hello"}
  • Lists
    • Values can be of any type
    • They are immutable. Hence, (de)concatenation returns a new list
    • When a list of ASCII numbers are seen, Elixir will print it as a charlist
    • Internally are stored as linked lists
  • Tuples
    • Values can be of any type
    • Internally stores elements contiguously in memory
    • They are also immutable
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