unify namespaces and objects

Namespaces are objects that can hold types, but cannot be passed around because don't have a type themselves.
Objects are mostly namespaces which can be passed around because they are typed, but cannot hold types in them.

Looks like this difference is a made up thing.

Consider unifying objects and namespaces.

possible resolution of #8308

so what is the proposal? and how is it different from #8308?

proposal goes: make namespaces first class citizens, which is

make it possible to close them over types and values from a current scope
return from a function
pass as a parameter

they are different in a scope of work, #8308 is (hopefully) less work and because of that might win over this request

pass as a parameter

i am guessing you mean define a parameter as a namespace, you can pass them now just fine.

not sure what you mean:

namespace N {
    type T = string;
}

function f(n: typeof N) { // <-- ?
    return <n.T> undefined;
}

the value N (the object literal equivalent) does not exist. so typeof N is nothing. namespace N { export var x; } has a type and it is { x: any }.

I still do not see much difference and/or proposals than #8308. i would rather have one issue.

which one is more likely to be implemented this (unifying objects and namespaces) or #8308 (adding types as pseudo-properties of objects)?

...does not exist. so typeof N is nothing

can you show an example of passing a namespace as an argument?

namespace N {
    export var x = 0;
}

function f(n: typeof N) {
    return
}

f(N) // OK
f({ x: 0 }); //OK


function f2(n: { x: number }) {
    return
}

f2(N) // OK
f2({ x: 0 }); //OK

i am talking about this

OK, so there is a value, i.e. the entity that exists at runtime in JS, there is a type, i.e. the design time construct that is defined in a TS file, and there is a namespace, something that can contain, values, types and other namespaces.

a name can have 1, 2, or all 3 meanings based on its declaration. so a class is both a type and a value. an enum, is a value, a type, and a namespace, etc..

you can read more about this at: http://www.typescriptlang.org/docs/handbook/declaration-merging.html

typeof value returns the type of a value. a namespace can not have a type. just cause it does not make much sense. in the example above, T is a type, it is not a property on the value N, it is just another type that is accessed using the name N.T.

this is what i meant by askign for a proposal on how this would fit in the existing design in #8308 (comment)

I think the two issues are the more or less the same issue, and a clear and detailed proposal is needed. marking this issue as a duplicate.

i am closing the other one (#8308) then

#420 seems vaguely related for the record.

The thing is that there is no value side to non-instantiated namespaces. Something like

namespace n {
    export interface Foo { }
}

doesn't actually have any associated emit, so it's not clear what you'd pass in for a function like

function foo(x: typeof n) {
    // ...
}

Does

foo(n);

compile to the following?

foo(undefined);

practically (as far as i know it) i only pass types and values (never types alone), although it is a valid question, need to find a use case that does it

side note, you don't need to pass types-only namespace, you can make it on site as you want:


    declare namespace HiThere<A, B, C> {
    }

    type NamepsceWithTypesThatINeed = HiThere<string, boolean, number>;

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unify namespaces and objects #8358

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unify namespaces and objects #8358

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mhegazy commented on Apr 28, 2016

zpdDG4gta8XKpMCd commented on Apr 28, 2016

mhegazy commented on Apr 28, 2016

zpdDG4gta8XKpMCd commented on Apr 28, 2016

mhegazy commented on Apr 28, 2016

mhegazy commented on Apr 28, 2016

zpdDG4gta8XKpMCd commented on Apr 28, 2016

mhegazy commented on Apr 28, 2016

zpdDG4gta8XKpMCd commented on Apr 28, 2016

mhegazy commented on Apr 28, 2016

zpdDG4gta8XKpMCd commented on Apr 28, 2016

DanielRosenwasser commented on Apr 28, 2016

zpdDG4gta8XKpMCd commented on Apr 28, 2016

zpdDG4gta8XKpMCd commented on Apr 28, 2016

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