Pantrypoints
Sigils
August 22, 2023 2 minutes • 308 words
Table of contents
Sigils
A sigil is a tilde with a character.
| Sigil | Generates.. |
|---|---|
| ~C | ..a character list with no escaping nor interpolation |
| ~c | ..a character list with escaping and interpolation |
| ~R | .. a regular expression with no escaping or interpolation |
| ~r | .. a regular expression with escaping and interpolation |
| ~S | .. a string with no escaping or interpolation |
| ~s | .. a string with escaping and interpolation |
| ~W | .. a word list with no escaping or interpolation |
| ~w | .. a word list with escaping and interpolation |
| ~N | .. a NaiveDateTime struct |
| ~U | .. a DateTime struct (since Elixir 1.9.0) |
| ~D | converts to date which can be accessed by .day .year .month |
Sigils are used with delimiters:
<…> A pair of pointy brackets {…} A pair of curly brackets […] A pair of square brackets (…) A pair of parentheses |…| A pair of pipes /…/ A pair of forward slashes “…” A pair of double quotes ‘…’ A pair of single quotes
Char List
~c/2 + 7 = #{2 + 7}/ #interpolates
'2 + 7 = 9'
~C/2 + 7 = #{2 + 7}/ #does not interpolate
'2 + 7 = \#{2 + 7}'
Regex
re = ~r/elixir/
~r/elixir/
iex> "Elixir" =~ re
false
iex> "elixir" =~ re
true
string = "100_000_000"
"100_000_000"
iex> Regex.split(~r/_/, string) # ~r/_/ splits the _ and .split turns it to a list
["100", "000", "000"]
String
~s/welcome to elixir #{String.downcase "SCHOOL"}/
"welcome to elixir school"
~S/welcome to elixir #{String.downcase "SCHOOL"}/
"welcome to elixir \#{String.downcase \"SCHOOL\"}"
Word List
iex> ~w/i love #{'e'}lixir school/
["i", "love", "elixir", "school"]
iex> ~W/i love #{'e'}lixir school/
["i", "love", "\#{'e'}lixir", "school"]
NaiveDateTime
NaiveDateTime.from_iso8601("2015-01-23 23:50:07") == {:ok, ~N[2015-01-23 23:50:07]}
DateTime
DateTime.from_iso8601("2015-01-23 23:50:07Z") == {:ok, ~U[2015-01-23 23:50:07Z], 0}
DateTime.from_iso8601("2015-01-23 23:50:07-0600") == {:ok, ~U[2015-01-24 05:50:07Z], -21600}
Custom Sigils
defmodule MySigils do
def sigil_p(string, []), do: String.upcase(string)
end
import MySigils
nil
~p/elixir school/
ELIXIR SCHOOL