Yeah, honestly, I'm wondering, not even why people are against plan-mode, but how they're getting stuff done without it.
Maybe it's me (it usually is), but I don't give an LLM small tasks that a human could knock out in a half-day. I give them big tasks, stuff that would take a human a few months to a year - and then I ask it to give me a plan, as a living document, and we spend a good hour or two iterating over the plan.
Then, when its finally at the point where I'm happy with the plan, and I've talked it down from wherever it first wanted to go, or pointed out that we don't need to be all-things-to-all-(wo)men and focus is important, I get it to start going through it.
Likewise, I get it to maintain TODO.md with lists of known bugs, separate lists of future-features, and again, I make a rule that this file must be updated whenever something material changes. I just asked Claude "where are we ?" and got back stuff like:
The ## Still-open detail section lists two items:
- Task #1070: the ported back end doesn't fold offsets into vector loads, so it emits an extra add on 11 files (from 892) at -O3. The output is correct, just longer.
- Task #1080: array sizes must constant-fold. For example, u8 buf[EVSZ * MAXEV] is rejected because size expressions only accept a literal.
This is for 'xc' [1] - a compiler for an Objective-C-like language (but without the excessive []). The language has ARC, blocks and bound-functions/methods named 'block' and 'callback', automatic parsing of DWARF data so you can #use a shared-object, so there's no header files - just read enums/types/functions/methods from the shared object. It's a cross-compiler, runs on mac,windows,linux and creates executables for mac,windows,linux,ios,android,WASM (amongst others). I have a binary running on my iPhone which was written on, and signed on a Linux box - no Apple software used at all. Oh, and it produces code that is very comparable to clang in speed on both arm64 and x86_64.
You can appreciate it's a reasonably large project. It's taken actual months(!) [grin] for me to get working. Months! There's no way I'd approach a problem like this without detailed plans of what I wanted the language to do, where we were going with it
FWIW, "I" wrote blewit.net [2] entirely in xc - both the server back-end (#use <psql> was very useful for binding to Postgres) and the WASM client - which share classes between client and back end, to make it very difficult to get out-of-step between them. No Apache (#use <tls>), no scripting, just a lean-and-mean daemon talking to postgres via valkey (#use <valkey>) - a reddis-alike. Oh yeah, blewit.net has a plan too. Actually it has lots of planning :)
1: https://compile-xc.org/compiler/
2: https://blewit.net/