Hi everyone. I’m Erica from the Mojo Docs team :waving_hand: We’re trying to get a better picture of where people struggle when adopting Mojo, especially early on. I’m not looking for “what’s wrong with Mojo” but for what felt painful, confusing, frustrating, or slow to click for you. This can be a…

[image] JosephWakeling: I suspect I’m finding this grating because my concept of Mojo has been roughly, “Performance matching or exceeding C/C++/Rust/D, ease of use comparable to Python/D”, and so the fact that metaprogramming isn’t easy feels like a big wrench, and also a potential ongoing pain…

Thank you; this is certainly helpful for newcomers. One thing I would suggest to work on is the parallelism between Python and mojo examples. For example when writing on mutability, the examples for Python and mojo do different things, and the example fn foo(mut value: Int): value += 1 # This w…

[image] owenhilyard: There are a lot of missing things in Mojo right now, but you can think of traits like Rust traits but you can only use associated types. Can you give some examples of specific things you’ve tried to do with metaprogramming? Sorry for late response, it’s been a busy last f…

[image] erica_sadun: @JosephWakeling What are your thoughts on how Mojo names its metaprogramming elements, particularly the distinction between parameters and arguments? The syntax of using square brackets for compile-time parameters, regular parentheses for runtime arguments is fine. It’s j…

Also, related to Iterable and Iterator: I’d like to see a Bounded trait as a more general version of Sized, which would implement the bounds method that’s currently part of the Iterator trait, with Iterator itself being rewritten to derive from Bounded. (I’d be happy to try implementing this if th…

Great feedback, thanks! I’ll see if we can update the docs to clarify this.

I think that’s a pretty good page that covers some of the nuances in instances where Mojo and Python are similar. I guess my biggest complaint is that it doesn’t really touch on where there are glaring differences from Python. I realize that it’s not meant to be exhaustive and is more of a “cheat sh…

What made you want to throw your hands up or walk away? Lack of guidance on calling Mojo from C and other languages besides Python, and what’s possible/impossible at this moment. I’m working on a more ambitious followup to From OpenCL towards Mojo GPU kernels in digital photo editing (first look…

I totally agree with this. It’s currently not clear at all from the documentation what kinds of external interop is supported (or even possible) when interfacing with non-Mojo code that may be written in OpenCL/Metal/CUDA/HIP/etc. It would be very helpful to have a documentation page on what kinds …

The recent Int.__truediv__ change is so far the biggest frustration I have with Mojo. I literally had a “WAIT, WHAT?!” moment after updating, because it silently broke my code. I still hope this change will be reverted.

What Was Your Biggest “Wait, What?” Moment in Mojo?

Mojo

Turcik (Turcik) April 1, 2026, 7:05am 47

At this point it’s hard to pick the biggest “wait, what?” moment. They just dropped a new one: Proposal: Bounds checking and removing negative indexing

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What Was Your Biggest “Wait, What?” Moment in Mojo?

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