linter/checker for single-threaded state via numbered variables?

Fernando Benavides elbrujohalcon@REDACTED
Mon Jan 27 15:09:57 CET 2020

This looks like a great rule to add to Elvis
Would you mind writing an issue for it here
Or if you're brave enough, we also accept Pull Requests ;)


On Mon, Jan 27, 2020 at 2:22 PM Mikael Pettersson <mikpelinux@REDACTED>

> Since Erlang doesn't allow you to rebind a variable in a scope where it's
> already bound (that becomes a match instead), there is a convention of
> using numbered variables to denote successive "generations" of some object
> or state that's intended to be used in a single-threaded or linear way.
> For example:
> foo(X0) ->
>   X1 = update(X0),
>   case predicate(X1) of
>     true ->
>       X2 = another_update(X1),
>       persist(X2);
>     false ->
>      persist(X1)
>   end.
> Here, whenever X(N+1) becomes bound, X(N) should become unused, and it
> should be an error if X(N) did not become unused.  A variation is that the
> "final" value is the one without a number suffix.
> Is there any Erlang linter or style checker that can perform these types
> of checks?

Brujo Benavides
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