Hike (hike v0.1.0)
Hike is a library that provides elevated data types, namely Option, Either, and MayFail, in the Elixir programming language. These elevated data types offer additional functionality and safety compared to the basic data types provided by Elixir.
Option
: The Hike.Option
type represents a value that may or may not be present.
It allows you to handle cases where a value might be absent without resorting to using nil or throwing exceptions.
The Option type provides functions like bind, map, and match to perform operations on the encapsulated value while handling the absence of the value gracefully.
Either
: The Hike.Either
type represents a value that can be one of two possibilities: left or right.
It is commonly used to handle cases where a computation can result in either a successful outcome or a specific error.
The Either
type provides functions like bind_left
, bind_right
, map_left
, map_right
, and match
to perform operations on the encapsulated
values based on their respective sides.
MayFail
: The Hike.MayFail
type combines the benefits of both Option
and Either
.
It represents a value that can either succeed or fail, similar to Either, but allows for more fine-grained error handling and composition.
It provides functions like bind_success, bind_failure, map_success, and map_failure to work with the success and failure cases.
The primary purpose of Hike
is to enhance
- expressiveness,
- safety,
- and predictability in code by providing these elevated data types.
They enable developers to handle different scenarios and errors in a more structured and controlled manner, reducing the reliance on exceptions and mutable state.
The functional programming paradigm is promoted by focusing on
- immutability,
- pure functions,
- and composition, which leads to more maintainable and robust code.
By using Hike, developers can write code that is easier to reason about, handle potential errors explicitly, and compose operations on elevated data types in a more concise and declarative manner.
It defines
a struct
Hike.Option
with a single fieldvalue
which can either benil
or any other value of type<T>
.a struct
Hike.Either
that represents an "either/or" value. It can contain either aleft
value or aright
value, but not botha struct
Hike.MayFail
that represents an "either/or" value. It can contain either aFailure
value or aSuccess
value, but not both.
This implementation provides shorthand functions to work with Optional data, including mapping, filtering, applying and many more functions to the value inside the Optional data.
purpose of this is to provide shorthand functions at Hike
module itself.
## Example
iex> Hike.option(42)
%Hike.Option{value: 42}
iex> Hike.either(42)
%Hike.Either{l_value: nil, r_value: 42, is_left?: false}
iex> Hike.either({:ok, 42})
%Hike.Either{l_value: nil, r_value: 42, is_left?: false}
iex> Hike.either({:error, :ERROR_MSG})
%Hike.Either{l_value: :ERROR_MSG, r_value: nil, is_left?: true}
iex> Hike.mayfail(9)
%Hike.MayFail{failure: nil, success: 9, is_success?: true}
iex> Hike.mayfail({:ok, 9})
%Hike.MayFail{failure: nil, success: 9, is_success?: true}
iex> Hike.mayfail({:error, "ERR_MSG"})
%Hike.MayFail{failure: "ERR_MSG", success: nil, is_success?: false}
iex> option = Hike.option(42)
...> Hike.map(option, &(&1 * 2))
%Hike.Option{value: 84}
iex> eth = Hike.either(42)
...> Hike.map_left(eth, &(&1 * 2))
%Hike.Either{l_value: nil, r_value: 42, is_left?: false}
iex> eth = Hike.either(42)
...> Hike.map_right(eth, &(&1 * 2))
%Hike.Either{l_value: nil, r_value: 84, is_left?: false}
iex> may_fail = Hike.mayfail(9)
...> Hike.map_success(may_fail, &(&1 * 2))
%Hike.MayFail{failure: nil, success: 18, is_success?: true}
iex> defmodule HikeTest do
...> alias Hike
...> def divide(x, y), do: x / y
...> def test_divide(x, y) do
...> Hike.try(÷/2, x, y)
...> end
...> end
...> HikeTest.test_divide(4, 2) |> Hike.map_success(fn x -> x + 1 end)
...> HikeTest.test_divide(4, 0) |> Hike.map_success(fn x -> x + 1 end)
%Hike.MayFail{failure: nil, success: 3.0, is_success?: true}
%Hike.MayFail{
failure: "bad argument in arithmetic expression",
success: nil,
is_success?: false
}
Application didn't crash but successfully return error.
like this example all other function can be used from Hike
module itself.
Link to this section Summary
Types
generic input type <T>
.
generic input type <TArg1>
.
generic input type <TArg2>
.
generic input type <TArg3>
.
generic input type <TArg4>
.
generic return type <TR>
.
Functions
wraps a function call if function runs successfully will return MayFail
in Success
state
otherwise return MayFail
in Failure
state.
wraps a function with arity 1 call if function runs successfully will return MayFail
in Success
state
otherwise return MayFail
in Failure
state.
wraps a function with arity 2 call if function runs successfully will return MayFail
in Success
state
otherwise return MayFail
in Failure
state.
wraps a function with arity 3 call if function runs successfully will return MayFail
in Success
state
otherwise return MayFail
in Failure
state.
wraps a function with arity 4 call if function runs successfully will return MayFail
in Success
state
otherwise return MayFail
in Failure
state.
Link to this section Types
exception()
@type exception() :: :error
@type t() :: any()
generic input type <T>
.
tArg1()
@type tArg1() :: any()
generic input type <TArg1>
.
tArg2()
@type tArg2() :: any()
generic input type <TArg2>
.
tArg3()
@type tArg3() :: any()
generic input type <TArg3>
.
tArg4()
@type tArg4() :: any()
generic input type <TArg4>
.
tr()
@type tr() :: any()
generic return type <TR>
.
Link to this section Functions
apply(opt, func)
@spec apply(Hike.Option.option(t()), Hike.Option.func(t())) :: Hike.Option.option(tr())
@spec apply(Hike.Option.option(), Hike.Option.func() | Hike.Option.func(t())) :: Hike.Option.option()
apply_failure(mayfail, func)
@spec apply_failure( Hike.MayFail.mayfail_failure(Hike.MayFail.t_failure()), Hike.MayFail.func(Hike.MayFail.t_failure()) ) :: Hike.MayFail.mayfail_failure(tr())
@spec apply_failure( Hike.MayFail.mayfail_success(Hike.MayFail.t_success()), Hike.MayFail.func(Hike.MayFail.t_failure()) ) :: Hike.MayFail.mayfail_success(Hike.MayFail.t_success())
apply_left(eth, func)
@spec apply_left( Hike.Either.either_left(Hike.Either.t_left()), (Hike.Either.t_left() -> tr()) ) :: Hike.Either.either_left(tr())
@spec apply_left( Hike.Either.either_right(Hike.Either.t_right()), (Hike.Either.t_left() -> tr()) ) :: Hike.Either.either_right(Hike.Either.t_right())
apply_right(eth, func)
@spec apply_right( Hike.Either.either_right(Hike.Either.t_right()), (Hike.Either.t_right() -> tr()) ) :: Hike.Either.either_right(tr())
@spec apply_right( Hike.Either.either_left(Hike.Either.t_left()), (Hike.Either.t_right() -> tr()) ) :: Hike.Either.either_left(Hike.Either.t_left())
apply_success(mayfail, func)
@spec apply_success( Hike.MayFail.mayfail_success(Hike.MayFail.t_success()), Hike.MayFail.func(Hike.MayFail.t_success()) ) :: Hike.MayFail.mayfail_success(tr())
@spec apply_success( Hike.MayFail.mayfail_failure(Hike.MayFail.t_failure()), Hike.MayFail.func(Hike.MayFail.t_success()) ) :: Hike.MayFail.mayfail_failure(Hike.MayFail.t_failure())
bind(opt, func)
@spec bind(Hike.Option.option(), Hike.Option.binder() | Hike.Option.binder(t())) :: Hike.Option.option()
@spec bind(Hike.Option.option(t()), Hike.Option.binder(t())) :: Hike.Option.option(tr())
bind_failure(mayfail, func)
@spec bind_failure( Hike.MayFail.mayfail_failure(Hike.MayFail.t_failure()), Hike.MayFail.binder(Hike.MayFail.t_failure()) ) :: Hike.MayFail.mayfail_failure(tr())
@spec bind_failure( Hike.MayFail.mayfail_failure(Hike.MayFail.t_success()), Hike.MayFail.binder(Hike.MayFail.t_failure()) ) :: Hike.MayFail.mayfail_failure(Hike.MayFail.t_success())
bind_left(eth, func)
@spec bind_left( Hike.Either.either_left(Hike.Either.t_left()), Hike.Either.binder(Hike.Either.t_left()) ) :: Hike.Either.either_left(tr()) | Hike.Either.either_right(tr())
@spec bind_left( Hike.Either.either_right(Hike.Either.t_right()), Hike.Either.binder(Hike.Either.t_left()) ) :: Hike.Either.either_right(Hike.Either.t_right())
bind_right(eth, func)
@spec bind_right( Hike.Either.either_right(Hike.Either.t_right()), Hike.Either.binder(Hike.Either.t_right()) ) :: Hike.Either.either_right(tr()) | Hike.Either.either_left(tr())
@spec bind_right( Hike.Either.either_left(Hike.Either.t_left()), Hike.Either.binder(Hike.Either.t_right()) ) :: Hike.Either.either_left(Hike.Either.t_left())
bind_success(mayfail, func)
@spec bind_success( Hike.MayFail.mayfail_success(Hike.MayFail.t_success()), Hike.MayFail.binder(Hike.MayFail.t_success()) ) :: Hike.MayFail.mayfail_success(tr())
@spec bind_success( Hike.MayFail.mayfail_failure(Hike.MayFail.t_failure()), Hike.MayFail.binder(Hike.MayFail.t_success()) ) :: Hike.MayFail.mayfail_failure(Hike.MayFail.t_failure())
either(value)
@spec either({:ok, t()}) :: Hike.Either.either_right(t())
@spec either({:error, t()}) :: Hike.Either.either_left(t())
@spec either(t()) :: Hike.Either.either_right(t())
failure(msg)
@spec failure(exception()) :: Hike.MayFail.mayfail_failure(exception())
filter(opt, func)
left(value)
@spec left(t()) :: Hike.Either.either_left(t())
map(opt, func)
@spec map(Hike.Option.option(), Hike.Option.mapper()) :: Hike.Option.option(t())
@spec map(Hike.Option.option(), Hike.Option.mapper() | Hike.Option.mapper(t())) :: Hike.Option.option()
map_failure(mayfail, func)
@spec map_failure( Hike.MayFail.mayfail_failure(Hike.MayFail.t_failure()), Hike.MayFail.mapper(Hike.MayFail.t_failure()) ) :: Hike.MayFail.mayfail_failure(tr())
@spec map_failure( Hike.MayFail.mayfail_failure(Hike.MayFail.t_success()), Hike.MayFail.mapper(Hike.MayFail.t_failure()) ) :: Hike.MayFail.mayfail_failure(Hike.MayFail.t_success())
map_left(eth, func)
@spec map_left( Hike.Either.either_left(Hike.Either.t_left()), (Hike.Either.t_left() -> tr()) ) :: Hike.Either.either_left(tr())
@spec map_left( Hike.Either.either_right(Hike.Either.t_right()), (Hike.Either.t_left() -> tr()) ) :: Hike.Either.either_right(Hike.Either.t_right())
map_right(eth, func)
@spec map_right( Hike.Either.either_right(Hike.Either.t_right()), (Hike.Either.t_right() -> tr()) ) :: Hike.Either.either_right(tr())
@spec map_right( Hike.Either.either_left(Hike.Either.t_left()), (Hike.Either.t_right() -> tr()) ) :: Hike.Either.either_left(Hike.Either.t_left())
map_success(mayfail, func)
@spec map_success( Hike.MayFail.mayfail_success(Hike.MayFail.t_success()), Hike.MayFail.mapper() ) :: Hike.MayFail.mayfail_success(tr())
@spec map_success( Hike.MayFail.mayfail_failure(Hike.MayFail.t_failure()), Hike.MayFail.mapper(Hike.MayFail.t_success()) ) :: Hike.MayFail.mayfail_failure(Hike.MayFail.t_failure())
match(opt, some_func, none_func)
@spec match( Hike.Option.option(t()) | Hike.Option.option(), Hike.Option.func(t()), Hike.Option.func() ) :: tr()
@spec match( Hike.Either.either(Hike.Either.t_left(), Hike.Either.t_right()), (Hike.Either.t_left() -> tr()), (Hike.Either.t_right() -> tr()) ) :: tr()
@spec match( Hike.MayFail.mayfail(Hike.MayFail.t_failure(), Hike.MayFail.t_success()), (Hike.MayFail.t_failure() -> tr()), (Hike.MayFail.t_success() -> tr()) ) :: tr()
mayfail(value)
@spec mayfail({:ok, t()}) :: Hike.MayFail.mayfail_success(t())
@spec mayfail({:error, exception()}) :: Hike.MayFail.mayfail_failure(exception())
@spec mayfail(t()) :: Hike.MayFail.mayfail_success(t())
option()
@spec option() :: Hike.Option.option()
option(value)
@spec option({:ok, t()}) :: Hike.Option.option(t())
@spec option({:error, exception()}) :: Hike.Option.option()
@spec option(t()) :: Hike.Option.option() | Hike.Option.option(t())
right(value)
@spec right(t()) :: Hike.Either.either_right(t())
success(value)
@spec success(t()) :: Hike.MayFail.mayfail_success(t())
try(func)
@spec try((() -> tr() | exception())) :: Hike.MayFail.mayfail()
wraps a function call if function runs successfully will return MayFail
in Success
state
otherwise return MayFail
in Failure
state.
try(func, arg1)
@spec try((tArg1() -> tr() | exception()), tArg1()) :: Hike.MayFail.mayfail()
wraps a function with arity 1 call if function runs successfully will return MayFail
in Success
state
otherwise return MayFail
in Failure
state.
example
Example
iex> add1 = fn (x) -> x + 1 end
iex> Hike.try(add1, 5) |> Hike.MayFail.map_success(fn x -> x end )
%Hike.MayFail{failure: nil, success: 6, is_success?: true}
try(func, arg1, arg2)
wraps a function with arity 2 call if function runs successfully will return MayFail
in Success
state
otherwise return MayFail
in Failure
state.
example
Example
iex> divide = fn (x, y) -> x / y end
iex> Hike.try(divide, 5, 0) |>
...> Hike.MayFail.map_success(fn x -> {:ok, x + 1} end ) |>
...> Hike.MayFail.map_failure(fn x -> String.upcase(x) end)
%Hike.MayFail{
failure: "BAD ARGUMENT IN ARITHMETIC EXPRESSION",
success: nil,
is_success?: false
}
try(func, arg1, arg2, arg3)
@spec try( (tArg1(), tArg2(), tArg3() -> tr() | exception()), tArg1(), tArg2(), tArg3() ) :: Hike.MayFail.mayfail()
wraps a function with arity 3 call if function runs successfully will return MayFail
in Success
state
otherwise return MayFail
in Failure
state.
try(func, arg1, arg2, arg3, arg4)
@spec try( (tArg1(), tArg2(), tArg3(), tArg4() -> tr() | exception()), tArg1(), tArg2(), tArg3(), tArg4() ) :: Hike.MayFail.mayfail()
wraps a function with arity 4 call if function runs successfully will return MayFail
in Success
state
otherwise return MayFail
in Failure
state.