Thanks: http://elixirschool.com/lessons/basics/sigils/
其作用就是实现对字面量的转义。
以下Sigils 大写表示原样输出，小写表示计算后输出
Char List
~c 和~C
iex(7)> ~c/2 + 7 = #{2 + 7}/
'2 + 7 = 9'
iex(8)> ~C/2 + 7 = #{2 + 7}/
'2 + 7 = \#{2 + 7}'
正则表达式
~r 和~R
re = ~r/elixir/
"Elixir" =~ re
# false
"elixir" =~ re
# true
忽略大小写:
re = ~r/elixir/i
"elixir" =~ re
# true
"Elixir" =~ re
# true
Regex API
s = "100_000_000"
Regex.split(~r/_/,s)
# ["100", "000", "000"]
String
~s 和~S
~s/welcome to elixir #{String.upcase "school"}/
# "welcome to elixir SCHOOL"
~S/welcome to elixir #{String.upcase "school"}/
# "welcome to elixir \#{String.upcase \"school\"}"
Word List
~w 和~W
~w/i love #{'e'}lixir school/
# ["i", "love", "elixir", "school"]
~W/i love #{'e'}lixir school/
# ["i", "love", "\#{'e'}lixir", "school"]
自定义Sigil ~u
小写字符串转大写
defmodule MySigils do
def sigil_u(string, []), do: String.upcase(string)
end
import MySigils
~u/elixir school/
ELIXIR SCHOOL
以上Sigils 大写表示原样输出，小写表示计算后输出。并且list 可用以下分隔符包裹（示例中使用的是/.../）：
<...>,
{...},谨慎使用会与#{}存在冲突
[...],
(...),
|...|,
/.../,
"...",
'...'
