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"""
The most atomic way to train and run inference for a GPT in pure, dependency-free Python.
This file is the complete algorithm.
Everything else is just efficiency.
@karpathy
"""
import os # os.path.exists
import math # math.log, math.exp
@wong2
wong2 / claude-code-tools.md
Last active March 12, 2026 16:26
Tools and system prompt of Claude Code

Task

Launch a new agent that has access to the following tools: Bash, Glob, Grep, LS, exit_plan_mode, Read, Edit, MultiEdit, Write, NotebookRead, NotebookEdit, WebFetch, TodoRead, TodoWrite, WebSearch. When you are searching for a keyword or file and are not confident that you will find the right match in the first few tries, use the Agent tool to perform the search for you.

When to use the Agent tool:

  • If you are searching for a keyword like "config" or "logger", or for questions like "which file does X?", the Agent tool is strongly recommended

When NOT to use the Agent tool:

  • If you want to read a specific file path, use the Read or Glob tool instead of the Agent tool, to find the match more quickly
  • If you are searching for a specific class definition like "class Foo", use the Glob tool instead, to find the match more quickly
  • If you are searching for code within a specific file or set of 2-3 files, use the Read tool instead of the Agent tool, to find the match more quickly
// Compile with clang or MSVC (WINDOWS ONLY RN)
//
// Implementing a POC green threads system using safepoints to show how cheap and simple it can
// be done, all you need to do is call SAFEPOINT_POLL in your own language at the top of every
// loop and function body (you can loosen up on this depending on the latency of pausing you're
// willing to pay). Safepoint polling is made cheap because it's a load without a use site
// which means it doesn't introduce a stall and pays a sub-cycle cost because of it (wastes resources
// sure but doesn't block up the rest of execution).
//
// # safepoint poll
@IshaanAdarsh
IshaanAdarsh / GSoC ’23 Project-Report.md
Last active June 17, 2025 09:34
Google Summer of Code 2023 (PostgreSQL)

Google Summer of Code 2023 Final Work Product


gsoc


Introduction

@pkhuong
pkhuong / yannakakis.md
Last active November 8, 2024 15:56
A minimal version of Yannakakis's algorithm for mostly plain Python
#!/usr/bin/env sed -re s|^|\x20\x20\x20\x20| -e s|^\x20{4}\x23\x23{(.*)$|<details><summary>\1</summary>\n| -e s|^\x20{4}\x23\x23}$|\n</details>| -e s|^\x20{4}\x23\x23\x20?|| -e s|\x0c|\x20|
license, imports
# Yannakakis.py by Paul Khuong
#
# To the extent possible under law, the person who associated CC0 with
# Yannakakis.py has waived all copyright and related or neighboring rights
# to Yannakakis.py.

# I happened to be looking at some of Cranelift's code, and I noticed that their constant-time dominates()
# check was using a somewhat more ad-hoc version of a hidden gem from the data structures literature called the
# parenthesis representation for trees. As far as I know, this was invented by Jacobson in his 1989 paper
# Space-Efficient Static Trees and Graphs. I first learned about it from the slightly later paper by Munro and Raman
# called Succinct Representations of Balanced Parentheses and Static Trees. I figured I'd give it an extremely
# quick intro and then show how it leads to a (slightly better) version of Cranelift's algorithm.
#
# This parenthesis representation of trees is surprisingly versatile, but its most striking feature is that
# it lets us query the ancestor relationship between two nodes in a tree in constant time, with a few instructions.
# And the idea is extremely simple and intuitive if you just draw the right kind of picture.
// This can grow a Robin Hood linear probing hash table near word-at-a-time memcpy speeds. If you're confused why I use 'keys'
// to describe the hash values, it's because my favorite perspective on Robin Hood (which I learned from Paul Khuong)
// is that it's just a sorted gap array which is MSB bucketed and insertion sorted per chain:
// https://pvk.ca/Blog/2019/09/29/a-couple-of-probabilistic-worst-case-bounds-for-robin-hood-linear-probing/
// The more widely known "max displacement" picture of Robin Hood hashing also has strengths since the max displacement
// can be stored very compactly. You can see a micro-optimized example of that here for small tables where the max displacement
// can fit in 4 bits: Sub-nanosecond Searches Using Vector Instructions, https://www.youtube.com/watch?v=paxIkKBzqBU
void grow(Table *table) {
u64 exp = 64 - table->shift;
// We grow the table downward in place by a factor of 2 (not counting the overflow area at table->end).
@creativcoder
creativcoder / main.rs
Last active November 5, 2023 13:23
Merge k sorted arrays in Rust
// Blog post: https://creativcoder.dev/merge-k-sorted-arrays-rust
// Merge 2 sorted arrays
fn merge_2(a: &[i32], b: &[i32]) -> Vec<i32> {
let (mut i, mut j) = (0, 0);
let mut sorted = vec![];
let remaining;
let remaining_idx;
loop {
if a[i] < b[j] {
@keichan34
keichan34 / config.fish
Created April 17, 2020 01:24
My Fish-shell config
function fish_greeting
echo "! COMPUTER_NAME"
end
set -x EDITOR vim
set -x LESS -asrRix8
set -x LANG en_US.UTF-8
set -x LC_ALL en_US.UTF-8
set -x LANGUAGE en_US.UTF-8
@pkhuong
pkhuong / dynamic-variance.py
Last active January 9, 2023 21:03
Fully dynamic variance for a bag of observations
import math
import struct
import unittest
import hypothesis.strategies as st
from hypothesis.stateful import Bundle, RuleBasedStateMachine, consumes, invariant, multiple, precondition, rule
class VarianceStack:
def __init__(self):
self.n = 0