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Comment by ejcx | Hacker News Reader

This is awesome. Ignoring the fact that it is written in Go, the iOS calculator only goes up to 100,000,000 and it is super annoying. Free ones have obnoxious advertisements.

Now, I want to learn to write iOS apps in Go as well.. Super neat and a great app to start with

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Fun trick: turn your phone to landscape mode while in Calculator and you get 26 digits instead of 9.

26? I get 15 digits before it switches to exponent representation. This is on iPhone 5s running iOS 8.4.

15 decimal digits around is the approximate limit for a 64-bit IEEE floating-point number, which is what the built-in Calculator uses (most non-integral math done on computers uses either 32-bit of 64-bit IEEE floating-point numbers). The exponential notation is because floating-point numbers can represent absurdly large values, it just is limited on precision. So you can represent 10^31, you just can't represent 10^31 + 1.

Why should the user of a calculator care how the numbers are represented internally?

More importantly, why should they be forced to?

It's a bug.

Well, what if these users you speak of are trying to accomplish more than just homework?

Some users do expect arbitrary precision for basic operations (addition, subtraction, multiplication, division) since the Calculator app that comes with Windows does it[0].

[0] http://blog.codinghorror.com/if-you-dont-change-the-ui-nobod...

Yep, typo, 16 not 26.

I could possibly see the point of this if Swift didn't exist (ObjC is my second least-favorite language, right behind C ), but otherwise it seems like little more than an interesting POC.

The point is to demonstrate that Go runs on iOS, regardless of what other languages also run on iOS.

That's not news, Apple allows a lot of languages to run on their OS now.

What matters is: how extensive is the support for this language on iOS? As far as this app shows, the support for Go looks very primitive and not really applicable to anything but toy apps.

You can write business logic for both iOS and Android using Go and only have to write the UI specific stuff in Swift/objc or Java.

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