Add build platform enum

[zekth]

added an enum for the build platform and exported it to be exposed to user. And make it consistent for any other plaform update. To be used like:

if(Deno.plaform == BuildPlatform.win) {

[ry]

Rename this to OperatingSystem.
And export this from js/deno.ts too.

CI is failing because of formatting. Run tools/format.py

[kevinkassimo]

Hmm OperatingSystem sounds like a really long name, personally preferring OSType, OSKind (we already have ErrorKind) or other similar names...

[ry]

Sure OSKind is fine. I think the longness doesn't matter much, since this is a fairly internal bit of code.

[zekth]

Agreed with @kevinkassimo . So i rename it to OSType ?

[ry]

sure

[kevinkassimo]

LGTM

[kitsonk]

What is the use case? I am not sure enums really add any value here over string literals. It requires an extra export too and string comparison is impaired. Just because you can doesn't mean we should.

[zekth]

As users may compare it, it's more revelant to add it to an enum instead of making string comparison. Avoiding mistakes. IMO as a user i don't really want to be bothered by OS is win / windows / win10 etc.

[ry]

LGTM

[kitsonk]

When using TypeScript, which you would for an enum anyways, string literals are just as "safe" as enums. You get errors as well as code completion in IDEs and you don't have to reference the type. I am still opposed to this.

[zekth]

And if for some reason you migrate the string from win to windows . Refactor of calling code is needed, not in the case of the enum.

[kitsonk]

But that is solving a problem we don't have. You can just as easily decide to rename BuildPlatform.win to BuildPlatform.windows as well. That argument doesn't make sense.

[zekth]

What ever, revert the PR if it's such a huge problem ....

[kevinkassimo]

I think this boils down whether we really want to enforce that all users to use TypeScript (or preferring at least CheckJS)...
There is so much uncertainty at this point whether Deno would be treated by the users as a real TS runtime or an alternative JS runtime. Similar debates happened months ago over adding runtime parameter type checks.
I'm personally ambivalent on this topic at this point. Guess I'll just wait and see public responses as Deno gradually improves and stabilizes...
(RN I'm looking forward much more on performance boost than ergonomics discussions. I've realized that I myself haven't actually used Deno for any real scenarios except for developing Deno itself, mostly due to performance issues)

[ry]

I'm sorry I merged before this conversation happened. I think Kitson has a point - I've asked him to set a fix PR which will change the enum to a type alias. (I also think it should be renamed to OperatingSystem from OSType...)

I think this boils down whether we really want to enforce that all users to use TypeScript

I definitely want this to be usable for normal JS too. This is part of browser compatibility, but also eschewing types is useful in many situations where I want to use Deno: prototyping, data cleaning, plotting.
If we were going to program in super strict type systems all day, we might as well use Rust - the benefit of this system is that we can opt in to different levels of type checking. Deno and deno_std obviously need the most strict linting and type checking, since these are complex bits of code meant for mass consumption. But we shouldn't force user code into that - only give them the option to opt-in.