PoudlardoLeanstral: Open-source agent for trustworthy coding and formal proof engineering
Lean 4 paper (2021): https://dl.acm.org/doi/10.1007/978-3-030-79876-5_37
It’s great to see this pattern of people realising that agents can specify the desired behavior then write code to conform to the specs.
TDD, verification, whatever your tool; verification suites of all sorts accrue over time into a very detailed repository of documentation of how things are supposed to work that, being executable, puts zero tokens in the context when the code is correct.
It’s more powerful than reams upon reams of markdown specs. That’s because it encodes details, not intent. Your intent is helpful at the leading edge of the process, but the codified result needs shoring up to prevent regression. That’s the area software engineering has always ignored because we have gotten by on letting teams hold context in their heads and docs.
As software gets more complex we need better solutions than “go ask Jim about that, bloke’s been in the code for years”.
I feel like the difference is minimal, if not entirely dismissable. Code in this sense is just a representation of the same information as someone would write in an .md file. The resolution changes, and that's where both detail and context are lost.
I'm not against TDD or verification-first development, but I don't think writing that as code is the end-goal. I'll concede that there's millions of lines of tests that already exist, so we should be using those as a foundation while everything else catches up.
Say you describe your kitchen as “I want a kitchen” - where are the knives? Where’s the stove? Answer: you abdicated control over those details, so it’s wherever the stochastic parrot decided to put them, which may or may not be where they ended up last time you pulled your LLM generate-me-a-kitchen lever. And it may not be where you want.
Don’t like the layout? Let’s reroll! Back to the generative kitchen agent for a new one! ($$$)
The big labs will gladly let you reroll until you’re happy. But software - and kitchens - should not be generated in a casino.
A finished software product - like a working kitchen - is a fractal collection of tiny details. Keeping your finished software from falling apart under its own weight means upholding as many of those details as possible.
Like a good kitchen a few differences are all that stands between software that works and software that’s hell. In software the probability that an agent will get 100% of the details right is very very small.
Details matter.
If it is fast enough, and cheap enough, people would very happily reroll specific subsets of decisions until happy, and then lock that down. And specify in more details the corner cases that it doesn't get just how you want it.
People metaphorically do that all the time when designing rooms, in the form of endless browsing of magazines or Tik Tok or similar to find something they like instead of starting from first principles and designing exactly what they want, because usually they don't know exactly what they want.
A lot of the time we'd be happier with a spec at the end of the process than at the beginning. A spec that ensures the current understanding of what is intentional vs. what is an accident we haven't addressed yet is nailed down would be valuable. Locking it all down at the start, on the other hand, is often impossible and/or inadvisable.
Agreed; often you don’t know quite what you want until you’ve seen it.
Spec is an overloaded term in software :) because there are design specs (the plan, alternatives considered etc) and engineering style specs (imagine creating a document with enough detail that someone overseas could write your documentation from it while you’re building it)
Those need distinct names or we are all at risk of talking past each other :)