How Effectively Agents Write D

[Peter Alexander]

Hey folks, long-time D user here and active contributor many 
years ago. I recently quit full-time employment to pursue some 
personal projects and expect to be doing a bunch of D-related 
work as well on the side in addition to using it for my main 
projects.

I've long felt that D could be a good language for LLM coding due 
to its fast compilation times, good runtime performance, safety, 
and expressive language features. Fast builds in particular feel 
more important when writing code is no longer the bottleneck.

This is just a feeling though, and I'm keen to start measuring it 
and sharing what I find with the community.

I've published an initial attempt to get data around agentic 
effectiveness with D at 
https://pja.name/2026/11/06/how-effectively-agents-write-d.html. 
Certainly not a perfect study by any means, but could serve as an 
initial starting point to iterate on the "agentic experience" of 
D.

The main takeaway from this study is that there are quite a lot 
of tooling-based improvements and changes to defaults that could 
significantly improve how agents use D. There are also some 
potential language changes, but I assume those are likely more 
difficult to make.

Keen to hear any and all feedback. Also interesting in what other 
ideas people have for how to measure D for agents.