Re: [RFC PATCH 1/1] Add a type for errors

[Eric Sunshine <sunshine@sunshineco.com>]

On Wed, Oct 2, 2024 at 6:04 PM brian m. carlson
<sandals@crustytoothpaste.net> wrote:
> On 2024-10-02 at 09:54:52, Phillip Wood wrote:
> > Part of the reason it works well in rust is that it supports discriminated
> > unions with pattern matching and has the "?" macro for early returns. In C
> > the code ends up being quite verbose compared to taking a pointer to error
> > struct as a function parameter and returning a boolean success/fail flag.
> >
> >     struct git_error e;
> >     struct object_id oid;
> >
> >     e = repo_get_oid(r, "HEAD", &oid);
> >     if (!GIT_ERROR_SUCCESS(e))
> >         return e;
> >
> > With a boolean return we can have
> >
> >     struct object_id oid;
> >
> >     if (repo_get_oid(r, "HEAD", &oid, e))
> >         return -1;
> >
> > where "e" is a "struct git_error*" passed into the function.
>
> However, Go still uses this kind of error handling, and many people use
> it every day with this limitation, so I don't think it's too awful for
> what we're getting.  I won't say that Go is my favourite language and I
> do prefer the less verbose error handling in Rust, but the fact that
> this design is widely used means that it's at least a defensible
> decision.

I'm not sure I understand your response to Phillip's observation.
Idiomatic error handling in Go:

    if oid, err := repo_get_oid(r, "HEAD"); err != nil {
        return err;
    }

seems much closer to Phillip's more succinct example than to the more
verbose example using GIT_ERROR_SUCCESS().