C is Brittle D is Plastic

[Derek Fawcus]

On Monday, 23 March 2026 at 01:51:40 UTC, Walter Bright wrote:
> On 3/22/2026 10:19 AM, Derek Fawcus wrote:
> LLMs don't really solve the problem, as the wrangled C code is 
> just as ugly looking.

In the example I cited, that was not an issue.  I was able to 
tightly specify the replacement, such that it effectively added 
as an editor "search and replace" facility on steroids.  So the 
result was exactly what I would have written.

I'm still in the process of evaluating LLM based agents in my 
workflow, but the above is one where I have concluded they are 
useful.  The one detrimental issue being the volume of change 
which may result from a global application to fix a poor pattern.


However, for your quoted example, that would not arise.  As there 
would only be the one (or small set of) function(s) implementing 
the algorithm to be changed, together with use of _Generic hidden 
by a macro to catch all of the call sites.

Only if that algorithmic change the proved to be valuable would 
it then be worth the cost of updating the call instances, and 
eliminating the _Generic using macro.  Then there the review cost 
for the LLM generated diffs would be minimal.


As to using an LLM agent to produce 'original' code for a 
project, I'm still skeptical.