Funx.Monad.Effect.Right

Mix.install([
  {:funx,
    git: "https://github.com/JKWA/funx.git",
    branch: "main"
  }
])

Overview

Represents the Right variant of the Effect monad, used to model a successful computation in an asynchronous context.

This module implements the following protocols:

• Funx.Monad: Implements the bind/2, map/2, and ap/2 functions to handle monadic operations within an effectful, lazy execution context.
• String.Chars: Provides a to_string/1 function to represent Right values as strings.

The Right effect allows the computation to proceed with successful values, supporting lazy, asynchronous tasks and capturing execution context through the Effect.Context struct.

Reader Operations

• ask/1 – Returns the environment passed to run/2 as a Right.
• asks/2 – Applies a function to the environment passed to run/2, wrapping the result in a Right.

Function Examples

import Funx.Monad.Effect.Right
alias Funx.Monad.Effect.Right

Functions

pure/2

Creates a new Right effect.

The pure/2 function wraps a value in the Right effect monad, representing an asynchronous success.

Examples

effect = pure("success")
Funx.Monad.Effect.run(effect)

ask/1

Returns a Funx.Monad.Effect.Right that yields the environment passed to Funx.Monad.Effect.run/2.

This is the Reader monad’s equivalent of ask, giving access to the entire injected environment for further computation.

Example

ask()
|> Funx.Monad.map(& &1[:user])
|> Funx.Monad.Effect.run(%{user: "alice"})

asks/2

Returns a Funx.Monad.Effect.Right that applies the given function to the environment passed to Funx.Monad.Effect.run/2.

This allows extracting a value from the environment and using it in an effectful computation, following the Reader pattern.

Example

asks(fn env -> env[:user] end)
|> Funx.Monad.bind(fn user -> Funx.Monad.Effect.right(user) end)
|> Funx.Monad.Effect.run(%{user: "alice"})