alt Hacker NewsIt fascinates me that really smart and experienced people have written that page and debated approaches for many years, and yet nowhere on that page is the Haskell-solution mentioned, which is the Maybe and Either monads, including their do-notation using the bind operator. Sounds fancy, intimidating even, but is a very elegant and functionally pure way of just propagating an error to where it can be handled, at the same time ensuring it's not forgotten.
This is so entrenched into everybody writing Haskell code, that I really can't comprehend why that was not considered. Surely there must be somebody in the Go community knowing about it and perhaps appreciating it as well? Even if we leave out everybody too intimidated by the supposed academic-ness of Haskell and even avoiding any religios arguments.
I really appreciate the link to this page, and overall its existence, but this really leaves me confused how people caring so much about their language can skip over such well-established solutions.
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Well, Rust's `?` was initially designed as a hardcoded/poor man's `Either` monad. They quote `?` as being one of the proposals they consider, so I think that counts?
Source: I'm one of the people who designed it.
It was not forgotten. Maybe/Either and 'do-notation' are literally what Rust does with Option/Result and '?', and that is mentioned a lot.
That said as mentioned in a lot of places, changing errors to be sum types is not the approach they're looking for, since it would create a split between APIs across the ecosystem.
> and yet nowhere on that page is the Haskell-solution mentioned
What do you mean? Much of the discussion around errors from above link is clearly based on the ideas of Haskell/monads. Did you foolishly search for "monad" and call it a day without actually reading it in full to reach this conclusion?
In fact, I would even suggest that the general consensus found there is that a monadic-like solution is the way forward, but it remains unclear how to make that make sense in Go without changing just about everything else about the language to go along with it. Thus the standstill we're at now.
I don't get why people keep thinking it was forgotten; I will just charitably assume that people saying this just don't have much background on the Go programming language. The reason why is because implementing that in any reasonable fashion would require massive changes to the language. For example, you can't build Either/Maybe in Go (well, of course you can with some hackiness, but it won't really achieve the same thing) in the first place, and I doubt hacking it in as a magic type that does stuff that can't be done elsewhere is something the Go developers would want to do (any more than they already have to, anyway.)
Am I missing something? Is this really a good idea for a language that can't express monads naturally?