undefined | Better HN

0 pointsunrealhoang2y ago0 comments

I think they are talking about the cons of Go allowing zero value. Rust doesn’t have that problem.

0 comments

Kamq2y ago

    type Gender int
    const (
        Unspecified Gender = iota
        Male
        Female
        Other
    )

Works the same way. Declaring an empty variable of the type Gender (var x Gender) results in unspecified.

stouset2y ago

…and now you need to check for nonsense values everywhere, instead of ever being able to know through the type system that you have a meaningful value.

It’s nil pointers all over again, but for your non-pointer types too! Default zero values are yet another own goal that ought to have been thrown away at the design stage.

Kamq2y ago

> instead of ever being able to know through the type system that you have a meaningful value.

That's... not what I'm looking for out of my type system. I'm mostly looking for autocomplete and possibly better perf because the compiler has size information. I really hate having to be a type astronaut when I work in scala.

So, I mean, valid point. And I do cede that point. But it's kind of like telling me that my car doesn't have a bowling alley.

2 more replies

the_gipsy2y ago

But it does not work. It looks like it would, with the indentation and iota keyword, but its just some variables that do not constrain the type. There will be incoming rogue values, from json or sql or something else.

    var g Gender // ok so far.
    if err := json.Unmarshal("99", &g); err != nil { panic(err) }
    // no error and g is Gender(99)!

Now you must validate, remember to validate, and do it in a thousand little steps in a thousand places.

Go is simple and gets you going fast... but later makes you stop and go back too much.

j / k navigate · click thread line to collapse

0 comments

Kamq2y ago

    type Gender int
    const (
        Unspecified Gender = iota
        Male
        Female
        Other
    )

Works the same way. Declaring an empty variable of the type Gender (var x Gender) results in unspecified.

stouset2y ago

…and now you need to check for nonsense values everywhere, instead of ever being able to know through the type system that you have a meaningful value.

It’s nil pointers all over again, but for your non-pointer types too! Default zero values are yet another own goal that ought to have been thrown away at the design stage.

Kamq2y ago

> instead of ever being able to know through the type system that you have a meaningful value.

So, I mean, valid point. And I do cede that point. But it's kind of like telling me that my car doesn't have a bowling alley.

2 more replies

the_gipsy2y ago

    var g Gender // ok so far.
    if err := json.Unmarshal("99", &g); err != nil { panic(err) }
    // no error and g is Gender(99)!

Now you must validate, remember to validate, and do it in a thousand little steps in a thousand places.

Go is simple and gets you going fast... but later makes you stop and go back too much.

j / k navigate · click thread line to collapse