elixir_cheatsheet.adoc

Elixir Cheatsheet

Sigils

Sigils support 8 different delimiters - //, ||, "", '', (), [], {}, <>.

Sigil	Explanation
~r()	Regular Expression
~s()	String (binary)
~c()	Char list
~w()s	Word list of strings (binaries)
~w()c	Word list of char lists
~w()a	Word list of atoms

Escape Codes

The following escape codes can be used in strings and char lists:

Code	Explanation	Code	Explanation
\\	single backslash	\a	bell/alert
\b	backspace	\d	delete
\e	escape	\f	form feed
\n	newline	\r	carriage return
\s	space	\t	tab
\v	vertical tab	\0	null byte
\xDD	represents a single byte in hexadecimal (such as \x13)	\uDDDD and \u{D…​}	represents a Unicode codepoint in hexadecimal (such as \u{1F600})

A double quote literal inside a double quoted string also needs to be escaped.

Metaprogramming

Various metaprogramming variables and macros.

Expression	Explanation
ENV	A struct containing details about the compilation environment
defmacro (name) do …​ end	Define a macro
quote do …​ end	Convert the code inside the block to AST
unquote(expression)	Use to inject values from outside of the quote block
def using	The using macro
_\_MODULE\_\_	Expands to the module name of the current module
CALLER
DIR
STACKTRACE

Structs, Maps, and Lists

Operation	List	Keyword List	Map	Struct
Define				---- defmodule Person do defstruct first_name: "", last_name: "" end ----
Create	[1,2,3]	[a: :foo]	%{a: :foo}	%Person{first_name: "Joe", last_name: "Armstrong"}
Match	[a, b | rest] = list	[a: value] = list	%{a: value} = map	%Person{first_name: name} = struct
Update	[new_value | list]		%{map | a: new_value}	%{first_name: new_value}

Comprehensions

for var1 <- generator1,
    var2 <- generator2,
    new_var = some_expr(var1, var2),
    a_check?(new_var) do
    operation_to_generate_final_value(var1, var2)
end

Elixir Guide Created by Stratus3D  Copyright 2018.  Source Code