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unify namespaces and objects #8358
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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 Nis 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 valuereturns the type of a value. a namespace can not have a type. just cause it does not make much sense. in the example above,Tis a type, it is not a property on the valueN, it is just another type that is accessed using the nameN.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>;Reacted by Alexey Golev
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