Re: New VSI post on Youtube

In article <vae3fe$1j523$1@dont-email.me>,
Arne Vajhøj  <arne@vajhoej.dk> wrote:

On 8/24/2024 9:33 PM, Stephen Hoffman wrote:

On 2024-08-20 12:36:51 +0000, Simon Clubley said:

One thing I wish was available in all languages is the ability to
return multiple values from a function call so you can return both a
status and the value(s) in one assignment. Ie: "a, b, c =
demo_function(param1, param2);".
>
In languages with dynamic associative arrays (such as PHP), I simulate
this by returning an associative array from a function call with both
status and value fields. Makes coding _so_ much cleaner and robust.

 
For those following along at home, C supports returning a struct.
 
Languages including Swift allow returning an "optional", where you
either get a value such as an object, or an indication or its absence.
Swift uses the concept of "unwrapping" a result marked optional, which
means you have to check before access.
 
Returning objects is more widely available, and hides a lot of this
mess, as well as hiding dealing with potentially-larger data buffers.
Objects and message-passing is akin to itemlist-based APIs, dragged
forward a few decades.
 
In other languages, support for an optional requires explicit code,
whether that might return a struct, or might return a value and a
sentinel, or ilk.

>
I don't know Swift but I will assume Swift optional is similar to
optional in other languages.
>
It solves the return both status and value problem. But it is
not a general multiple return value solution. And it is really
just a small evolution of the traditional "return null
indicate an error".
>
[snip overly long Java sequence]

What a failure of imagination.  When you have the Maybe monad,
it actually opens up a lot of ground for abstraction.
https://lexi-lambda.github.io/blog/2019/11/05/parse-don-t-validate/

- Dan C.