What's inside Google's new Go app for iOS and Android

https://sourcedna.com/blog/20150712/golang-on-ios.html

by KateLawson • 11 years ago

74 21 11 years ago

NateLawson7• 11 years ago

Hi, I'm the author. SourceDNA has built a platform for crawling the app stores & indexing app code. We provide app review, helping developers improve their code and security by finding apps that have out-of-date SDKs or use platform APIs incorrectly.

As a fun exercise, we looked into Google’s recent moves with Go 1.5 pre-release, which can compile apps for iOS and Android. They just published their first app (a calculator) on the app stores and we looked inside to see if there was anything too surprising. The apps are mostly Go, with a thin platform-specific UI and event layer but this does raise some questions about Google’s long-term mobile strategy.

Previous discussion about the app, including comments by one of the developers:

https://news.ycombinator.com/item?id=9875886

Let me know here if you have other questions. Is Google going after the cross-platform tools market? Is this the future of the Android SDK? Or is it just a curiosity?

Sphax• 11 years ago

Where did you get the idea that Go's syntax is inspired by Python ? I don't think I ever saw that claim before.

NateLawson7• 11 years ago

Array slices, godoc/pydoc, syntax relevance (export names by TitleCasing them), lack of semi-colons, etc. There's even a guide about it.

https://golang-for-python-programmers.readthedocs.org/en/lat...

It's not so much that the syntax was derived from Python (because it's not) as that the language was clearly informed by the authors' experience working commercially with Python, Java, and C projects.

ohleg• 11 years ago

Cool! I'm the developer of AnGoIde (the Go IDE that runs right on your Android device) and actually one of the future features was an option to generate APKs for custom CLI Go apps on Android; e.g., with a bootstrap GUI that just executes a Go binary. One challenge is supporting both ARM (different versions) and the x86 (gaining popularity) architectures, so I'm interested to see how the official tools will accommodate that going forward.

NateLawson7• 11 years ago

Go recently ported the toolchain to being self-hosted, so hopefully they can keep code-generation up to date as well. There's nothing special about the current Go mobile runtime so it should work on Android x86 as well.

http://golang.org/s/go13compiler

bgentry• 11 years ago

There was a great talk on the subject of Go for iOS/Android apps by Hana Kim at last week's Gophercon: https://sourcegraph.com/blog/live/gophercon2015/123653512740

NateLawson7• 11 years ago

Thanks, looks great. BTW, the notes say no support for os/exec, but this library code is definitely present in both apps. It may not be usable though. :-)

scosman3• 11 years ago

I disagree that there should be libraries for GUI components. As soon as you try that, you end up compromising the UX with either non-native UI components, or lowest common denominator APIs that try to bridge iOS/Android. Write your models/controllers and other logic in Go, but keep your views native and use go's bind tool.

Sidenote: You can write OpenGL ES apps in Go (aka games). These typically don't use native UI controls so that's a great use case for go mobile.

miguelrochefort• 11 years ago

How important is native UI to users? Is there any literature on the subject? I've always assumed it was important, but I keep seeing big name apps reinventing the UI and going the custom route.

scosman3• 11 years ago

Who are the big names you're referring to? Many of them highly customize the look of the controls (Spotify, AirBnb, MSFT) but they are still the native controls. The back stack, physics, etc are all native.

mwcampbell• 11 years ago

In addition to providing the look and feel that users expect, native UIs are the most practical way to achieve accessibility for people with disabilities, e.g. blind people using screen readers like VoiceOver (iOS) and TalkBack (Android). You can implement the platform accessibility APIs for a non-native UI, but it's a lot of work; just ask the relevant developers of Chrome and Firefox.

Addendum: If your app uses a web view, it can be accessible, as long as you use standard semantic HTML elements and/or add the appropriate ARIA attributes and focus behavior for custom widgets. But in this comment, I was comparing a native UI to something completely custom.

NateLawson7• 11 years ago

Yes, direct GL access with a thin app delegate is the most common way C++ game engines like Unreal Engine, Crytek, and Marmalade are packaged for iOS and Android. There's no reason you couldn't do that in Go too, except for the lack of other libraries like scripting, mesh, etc.

I'm not talking just a simple GUI abstraction wrapper, which has earned a deservedly bad reputation. The more full-fledged UI models have gotten much nicer, like in React Native or Xamarin.

mratzloff• 11 years ago

I agree.

Unless a third-party fills this vacuum, Golang on mobile will remain a curiosity.

No, it will be used for shared libraries, as intended.

NateLawson7• 11 years ago

Yes, that's a good point. Though I'm not sure what Go library would be worth the couple MB runtime overhead purely by itself. Ideas?

microtonal• 11 years ago

With syntax inspired by Python

If anything, the syntax is inspired by C, with Pascal-order type declarations (variable first, type thereafter).

michaelwww• 11 years ago

I wrote my first Go program this weekend. The syntax felt like a cross between Python and C, notably doing away with parens in if statements and returning multiple values.

NateLawson7• 11 years ago

Yes, this is what I was trying to say.

mjcohen• 11 years ago

You can't fool me - this is an attempt to bring back APL!

BuckRogers• 11 years ago

Rooting for this stuff to keep moving forward, because as a Python(2) user, my Python3 migration is going to be to Go. It's just the ecosystem I'm waiting to catch up before I take the big plunge and port my relevant apps.

What's inside Google's new Go app for iOS and Android

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