Fl4m3Ph03n1x
Monadex bind operator
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?
Marked As Solved
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
Also Liked
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.








