Can you elaborate on that a little bit? When you search like that, what do you type in to find stuff in a programming language source file? I'd like to better understand this workflow, it seems interesting and I might be missing out.
Khoj works more like an incremental, natural language version of org-agenda-search (or projectile) rather than isearch.
You've to configure which files it should index first. You can then use natural language to search those files with a search-as-you-type experience.
This is not the same as isearch that just searches the current file for keyword matches.
Second, khoj doesn't index source code and the default search models don't work well with code files.
But yeah someone should implement a natural language isearch as a standalone tool (as suggested by parent comment). It'd be super-useful