View Source Funx.Monad.Maybe.Just (funx v0.1.7)

Represents the Just variant of the Maybe monad, used to model the presence of a value.

A Just wraps a single value and participates in functional composition by propagating the contained value through monadic operations.

This module implements the following protocols:

  • Funx.Monad: Implements bind/2, map/2, and ap/2 for monadic composition.
  • Funx.Foldable: Provides fold_l/3 and fold_r/3 to fold over the wrapped value.
  • Funx.Filterable: Supports filtering with filter/2, filter_map/2, and guard/2.
  • Funx.Eq: Enables equality checks between Just and other Maybe values.
  • Funx.Ord: Defines ordering behavior between Just and Nothing.

These protocol implementations allow Just to participate in structured computation, validation, filtering, and comparison within the Maybe context.

Summary

Types

t(value)

Functions

pure(value)

Creates a new Just value.

Types

Link to this type

t(value)

View Source 
@type t(value) :: %Funx.Monad.Maybe.Just{value: value}

Functions

Link to this function

pure(value)

View Source 
@spec pure(value) :: t(value) when value: term()

Creates a new Just value.

The pure/1 function wraps a value in the Just monad, representing the presence of the value.

Examples 

iex> Funx.Monad.Maybe.Just.pure(5)
%Funx.Monad.Maybe.Just{value: 5}

Raises

  • ArgumentError if nil is provided.

    iex> Funx.Monad.Maybe.Just.pure(nil) ** (ArgumentError) Cannot wrap nil in a Just