cat - v1.1.0

cat/instances/monoid

Monoid instances: Unit, Bool (All and Any), List, Option, Tuple, Triple, Function.

Values

all_monoid

</> 
pub fn all_monoid() -> monoid.Monoid(Bool)

Monoid instance for Bool with (&&).

Examples

let bool_and_monoid = all_monoid()
True
|> bool_and_monoid.mappend(False)
|> bool_and_monoid.mappend(bool_and_monoid.mempty)
// -> False

any_monoid

</> 
pub fn any_monoid() -> monoid.Monoid(Bool)

Monoid instance for Bool with (||).

Examples

let bool_or_monoid = any_monoid()
False
|> bool_or_monoid.mappend(False)
|> bool_or_monoid.mappend(bool_or_monoid.mempty)
// -> False

function_monoid

</> 
pub fn function_monoid(
  mono_b: monoid.Monoid(b),
) -> monoid.Monoid(fn(a) -> b)

Monoid instance for functions where the result type must be a Monoid instance.

int_prod_monoid

</> 
pub fn int_prod_monoid() -> monoid.Monoid(Int)

Monoid instance for integer product.

Examples

int_prod_monoid()
|> mconcat([2, 3, int_prod_monoid().mempty, 4, int_prod_monoid().mempty])
|> int_prod_monoid().mappend(10)
// -> 240

int_sum_monoid

</> 
pub fn int_sum_monoid() -> monoid.Monoid(Int)

Monoid instance for integer sum.

Examples

int_sum_monoid().mappend(7, 8)
// -> 15
int_sum_monoid().mappend(4, int_sum_monoid().mempty)
// -> 4

list_monoid

</> 
pub fn list_monoid() -> monoid.Monoid(List(a))

Returns the canonical implementation of the monoid type for List.

Examples

let mono_list = list_monoid()
[1, 2]
|> mono_list.mappend([3, 4, 5])
|> mono_list.mappend(mono_list.mempty)
|> mono_list.mappend([6])
// -> [1, 2, 3, 4, 5, 6]

option_monoid

</> 
pub fn option_monoid(
  mono_a: monoid.Monoid(a),
) -> monoid.Monoid(option.Option(a))

Returns the canonical implementation of the monoid type for Option(a).
We must have a Monoid(a) type instance.

Examples

let mono_string = Monoid(mempty: "", mappend: fn(x: String, y: String) -> String { x <> y })
let mono_maybe = option_monoid(mono_string)

Some("ab")
|> mono_maybe.mappend(Some("cd"))
// -> Some("abcd")
mono_maybe.mappend(Some("abc"), maybe.mempty)
// -> None

triple_monoid

</> 
pub fn triple_monoid(
  mono_a: monoid.Monoid(a),
  mono_b: monoid.Monoid(b),
  mono_c: monoid.Monoid(c),
) -> monoid.Monoid(#(a, b, c))

Returns the canonical implementation of the monoid type for Triple.
We must have a Monoid type instance for a, b, and c.

tuple_monoid

</> 
pub fn tuple_monoid(
  mono_a: monoid.Monoid(a),
  mono_b: monoid.Monoid(b),
) -> monoid.Monoid(#(a, b))

Returns the canonical implementation of the monoid type for Tuple.
We must have a Monoid(a) and a Monoid(b) type instance.

unit_monoid

</> 
pub fn unit_monoid() -> monoid.Monoid(Nil)

Returns the canonical implementation of the monoid type for Nil (unit type).

Examples

let mono_unit = unit_monoid()
mono_unit.mappend(mono_unit.mempty, Nil)
// -> Nil
✨ Search Document