# Bubblewrap

Fork of `MonEx`, simplifying the `Option` type to be value that can be `nil`.

Bubblewrap implements two most common monadic data types:

- `Bubblewrap.Result` - container for a result of operation or error.
  Result can be created using a constructor macro: `ok(value)` or `error(e)`,
  where underlying structure is a tuple: `{:ok, value}` or `{:error, e}` respectively.

- `Bubblewrap.Option` - container for a value that might be present or missing.
  It is a simple wrapper around a value that could be `nil`.

- `Bubblewrap` - collection of utility functions to work with both of these types.

## Result

Result type fits perfectly with idiomatic Erlang/Elixir return values.
When some library function returns either `{:ok, val}` or `{:error, err}`,
you can use functions provided by Bubblewrap right away. The most typical example,
where Bubblewrap shines, is a pipeline, where each operation can fail. Normally
this would be organized in a form of nested case expressions:

    final = case op1(x) do
      {:ok, res1} ->
        case op2(res1) do
          {:ok, res2} -> op3(res2)
          {:error, e} -> {:error, e}
      {:error, e} -> {:error, e}

With Bubblewrap you can do the same using `flat_map` operation:

    final = op1(x) |> flat_map(&op2/1) |> flat_map(&op3/1)

Once any of the operations returns `error(e)`, following operations
are skipped and the error is returned. You can either do something
based on pattern matching or provide a fallback (can be a function or a default value).

    case final do
      ok(value) -> IO.puts(value)
      error(e) -> IO.puts("Oh, no, the error occured!")

    final |> fallback(ok("No problem, I got it"))

## Option

Option type is just an alias for `t() | nil`. With Option type, you can use the
same set of functions, such as `map`, `flat_map`, etc.

    |> map(&find_posts_by_user/1)

This will only request for posts if the user was found.

See docs per Result and Option modules for details. [docs](

## Installation

The package can be installed as:

1. Add `bubblewrap` to your list of dependencies in `mix.exs`:

   def deps do
     [{:bubblewrap, "~> 0.1.0"}]