Witchcraft.Functor (Witchcraft v1.0.4) View Source
Functors are datatypes that allow the application of functions to their interior values. Always returns data in the same structure (same size, tree layout, and so on).
Please note that bitstrings are not functors, as they fail the functor composition constraint. They change the structure of the underlying data, and thus composed lifting does not equal lifing a composed function. If you need to map over a bitstring, convert it to and from a charlist.
Type Class
An instance of Witchcraft.Functor must define Witchcraft.Functor.map/2.
Functor [map/2]Link to this section Summary
Functions
~>/2 with arguments flipped.
Operator alias for lift/2
map with its arguments flipped.
async_map/2 with arguments flipped.
The same as async_map/2, except with the mapping function curried
map a function over a data structure, with each mapping occuring asynchronously.
async_lift/2 with arguments flipped.
map/2 but with the function automatically curried
map a function into one layer of a data wrapper.
There is an autocurrying variant: lift/2.
lift/2 but with arguments flipped.
Replace all inner elements with a constant value
Link to this section Types
Specs
t() :: any()
Link to this section Functions
~>/2 with arguments flipped.
iex> (fn x -> x + 5 end) <~ [1,2,3]
[6, 7, 8]Note that the mnemonic is flipped from |>, and combinging directions can
be confusing. It's generally recommended to use ~>, or to keep <~ on
the same line both of it's arguments:
iex> fn(x, y) -> x + y end <~ [1, 2, 3]
...> |> List.first()
...> |> apply([9])
10...or in an expression that's only pointing left:
iex> fn y -> y * 10 end
...> <~ fn x -> x + 55 end
...> <~ [1, 2, 3]
[560, 570, 580]Operator alias for lift/2
Example
iex> [1, 2, 3]
...> ~> fn x -> x + 55 end
...> ~> fn y -> y * 10 end
[560, 570, 580]
iex> [1, 2, 3]
...> ~> fn(x, y) -> x + y end
...> |> List.first()
...> |> apply([9])
10Specs
map with its arguments flipped.
Examples
iex> across(fn x -> x + 1 end, [1, 2, 3])
[2, 3, 4]
iex> fn
...> int when is_integer(int) -> int * 100
...> value -> inspect(value)
...> end
...> |> across(%{a: 2, b: [1, 2, 3]})
%{a: 200, b: "[1, 2, 3]"}Specs
async_map/2 with arguments flipped.
Examples
iex> fn x -> x * 10 end
...> |> async_across([1, 2, 3])
[10, 20, 30]
fn x ->
Process.sleep(500)
x * 10
end
|> async_across(Enumto_list(0..10_000))
#=> [0, 10, ...] in around a secondSpecs
The same as async_map/2, except with the mapping function curried
Examples
iex> async_lift([1, 2, 3], fn x -> x * 10 end)
[10, 20, 30]
0..10_000
|> Enum.to_list()
|> async_lift(fn x ->
Process.sleep(500)
x * 10
end)
#=> [0, 10, ...] in around a secondSpecs
map a function over a data structure, with each mapping occuring asynchronously.
Especially helpful when each application take a long time.
Examples
iex> async_map([1, 2, 3], fn x -> x * 10 end)
[10, 20, 30]
0..10_000
|> Enum.to_list()
|> async_map(fn x ->
Process.sleep(500)
x * 10
end)
#=> [0, 10, ...] in around a secondSpecs
async_lift/2 with arguments flipped.
Examples
iex> fn x -> x * 10 end
...> |> async_over([1, 2, 3])
[10, 20, 30]
fn x ->
Process.sleep(500)
x * 10
end
|> async_over(Enumto_list(0..10_000))
#=> [0, 10, ...] in around a secondSpecs
map/2 but with the function automatically curried
Examples
iex> lift([1, 2, 3], fn x -> x + 1 end)
[2, 3, 4]
iex> [1, 2, 3]
...> |> lift(fn x -> x + 55 end)
...> |> lift(fn y -> y * 10 end)
[560, 570, 580]
iex> [1, 2, 3]
...> |> lift(fn(x, y) -> x + y end)
...> |> List.first()
...> |> apply([9])
10Specs
map a function into one layer of a data wrapper.
There is an autocurrying variant: lift/2.
Examples
iex> map([1, 2, 3], fn x -> x + 1 end)
[2, 3, 4]
iex> %{a: 1, b: 2} ~> fn x -> x * 10 end
%{a: 10, b: 20}
iex> map(%{a: 2, b: [1, 2, 3]}, fn
...> int when is_integer(int) -> int * 100
...> value -> inspect(value)
...> end)
%{a: 200, b: "[1, 2, 3]"}Specs
lift/2 but with arguments flipped.
Examples
iex> fn x -> x + 1 end |> over([1, 2, 3])
[2, 3, 4]Specs
Replace all inner elements with a constant value
Examples
iex> replace([1, 2, 3], "hi")
["hi", "hi", "hi"]