It does use line numbers, which definitely aren't infallible. That's why a `plandex changes` TUI is included to review changes before applying. Unfortunately no one has figured out a file update strategy yet that doesn't make occasional mistakes--probably we'll need either next-gen models or fine-tuning to get there.

That said, counting isn't necessarily required to use line numbers. If line numbers are included in the file when it's sent to the model, it becomes a text analysis task rather than a counting task. Here are the relevant prompts: https://github.com/plandex-ai/plandex/blob/main/app/server/m...