Fl4m3Ph03n1x

Fl4m3Ph03n1x

Background

I am trying a new library called Monadex and in specific I am trying the Result Monad. The documentation mentions a function called Result.bind and I have made it work with the following code snippet:

defmodule TestMonadex do
  use Monad.Operators

  import Monad.Result

  def p1(x) do
    x
    |> success()
    |> bind(&plus_1/1)
  end

  defp plus_1(n), do: n + 1
end

And so far so good.

Problem

The problem arises when I try to use the bind operator. According to the docs, this operator is the same thing as the Result.bind function. Following this logic, the following code snippet should work:

defmodule TestMonadex do
  use Monad.Operators

  import Monad.Result

  def p2(x) do
    success(x) ->> (&plus_1/1) # This does not compile!
  end

  defp plus_1(n), do: n + 1
end

Unfortunately, this is not compiling:

(SyntaxError) syntax error before: '>'

Stacktrace:
  │ (elixir 1.11.2) lib/kernel/parallel_compiler.ex:314: anonymous fn/4 in Kernel.ParallelCompiler.spawn_workers/7

an expression is always required on the right side of ->. Please provide a value after ->

At this point I strongly believe I am not understanding something from the docs or from the library.

Question

What a I doing wrong?

Showing Posts 1 to 5

dorgan

dorgan

The operator is ~>>, not ->>. It uses a tilde ~ instead of a dash. That code is parsed as

-> > (&plus_1/1)

Ie -> followed by the strictly greather than operator >, which is invalid.

Fl4m3Ph03n1x

Fl4m3Ph03n1x OP

So the documentation is wrong:

Or does it appear different in your browser ?

dorgan

dorgan

I still see a tilde, but the font choice may be a poor one and it’s easy to not spot the difference
It’s clearer looking at the source: MonadEx/lib/monad/operators.ex at master · rob-brown/MonadEx · GitHub
Or zooming:

Definitely an accessibility issue

Fl4m3Ph03n1x

Fl4m3Ph03n1x OP

Good point there, even the URL has a tilde.

Out of curiosity, what is your browser’s default font ?

dorgan

dorgan

The default one, it think it’s Arial since I’m on windows.
I do see the same as in your screenshot though, and the difference is barely noticeable.

— All posts loaded —

Where Next? Top

Trending in Questions Top

stjefim
Hello! Suppose you are building workflow (order / task / payment) processing system with the following requirements: Each workflow con...
New
itzmidinesh
Hi all, I’m working on a Phoenix project where I need to make external HTTP requests and I’m trying to choose between Req and HTTPoison....
New
pragdave
How do I tell Hologram not to escape HTML when substituting into templates? {Textile.render(@product.long_description)} escapes the HTM...
New
rlipscombe
I’d like to create a file with 600 permissions (rw-------), but there’s a race condition if I create it and then change the permissions. ...
New
leoschweizer
Hi, we run different LLM models across a cluster, with each node loading a configurable subset. Model-specific queues let nodes consume ...
New
rlipscombe
When I use Mix.install with a git dependency, using git@github.com:... how do I change the SSH identity used? I’ve got two Github accoun...
New
adr
Hello all. I have a question as to best practices for code organization when implementing a liveview with a lot of responsibilities. Sup...
New

Other Trending Topics Top

dominicletz
Hey there, I haven’t seen a list of useful Elixir specific skills for the popular AI tools yet so I’m starting one here with my first. ...
New
raa-ziq
Hi everyone :waving_hand: I wanted to share something I’ve been building — NowBlind, a random chat app designed to help people discover ...
New
mudasobwa
I fully migrated to my own harness from Anthropic/Gemini and I think it’s time to share it. Welcome DSH, the DeepSeek Harness, fully writ...
New
KristerV
Hey. Is there anyone here who creates agents in their apps? Not talking about using agents, but creating them. I’m finding it pretty diff...
New
OndrejValenta
(I just needed to vent somewhere and LinkedIn is full of hope, or hype, I’m not sure which exactly) AI dream has many faces, but general...
New
kip
Localize is the next generation localisation library for Elixir. Think of it as ex_cldr version 3.0. The first version will be released ...
New

Latest on Elixir Forum

We're in Beta

About us Mission Statement

Options

Thread Display Mode




Thread Preview

Skip Thread Previews