Anonymous functions in elixir
Anonymous functions are first class values in Elixir, they can be passed as arguments to other functions and also can be returned as a value.
Creating an anonymous function in elixir
f = fn(x) -> x * x end
or in short form
f = &(&1*&1)
where &1 will be replaced by the first argument.
Invoking an anonymous function
f.(2) # 2*2 => 4
Anonymous function can be created out of named functions as well. For example we can make String.upcase/1 as anonymous. By doing this we can pass them to other functions.
g = &String.upcase(&1)
g.("hello") # "HELLO"
Anonymous functions has many use cases, they can be used in Enum.map/2 function.
names = ["Deepak", "raghu", "Akram", "Stalin"]
Enum.map(names, g) # ["DEEPAK", "RAGHU", "AKRAM", "STALIN]
You many use pattern matching in anonymous function, in that case you need to use the same arity.
f = fn
(:square, x) -> x * x
(:cube, x) -> x * x * x
end
f.(:square, 4) # 16
f.(:cube, 4) # 64