New features for development in iOS 26 and MacOS 26 - Part 1
iOS 26 Beta, MacOS 26 Beta and iPadOS 26 Beta
Xcode and Coding Assistant
The basic structure of Xcode coming with the new Beta MacOS 26 is similar to the previous versions, but there are some improvements, as always. Since there was a lot of hype about coding with AIs lately, I wanted to use the new Coding Assistant that is embedded to Xcode. I had previously used ChatGPT itself, which has added the ability to work with windows on screen, thus enabling us to ask ChatGPT to use the code in Xcode windows to improve or whatever we want to do.
This implementation is just the opposite, namely you invoke ChatGPT from within Xcode, or if you do not prefer to use ChatGPT, then you can use Apple’s own internal on-device model.
While re-compiling some of my existing code to see how my software would look under the new Liquid Glass interface introduced in iOS 26, macOS 26 and iPadOS 26, I decided to ask the new Coding Assistant to improve some code (shown below).
As you can see from the dialog, ChatGPT is already aware of what code is active on screen and analyses it. It is also clear that it checks other source files as well (it refers to which other classes or functions it will check).
It correctly identified the redundant use of findPersonWithID in the implementation and even suggested a - good - implementation that gets rid of the redundancy.
The second suggestion is more subtle, since it is based on a more complex analysis. Detecting that the function property is used as an integer and is used as an index for a string array, it suggested an alternate implementation.
The third suggestion is also fine, with the fourth suggestion being a minor UI fix.
The rest are minor suggestions as well, but it is still useful.
At the end of the session, ChatGPT suggests to apply all the suggestions. I did not do that, but it is obviously a time saver when a lot of changes are applied.
Performance
This was mentioned ion the Platforms State of the Union talk on the first day of WWDC. I do not have any metrics, but I realised that my Library application in preparation suddenly started to perform 2-3 times faster when I recompiled it with Xcode 26. My application heavily uses SwiftUI and SwiftData. I still have to check what has actually improved, but the performance with close to 6000 book records and several thousand authors and publishers, the application is quite snappy now.
(… to be continued)