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# gtr ─ Git worktree helper
#
# Examples
# --------
#   gtr create feature0          # add ~/code/worktrees/feature0 (branch claude/feature0)
#   gtr create feat1 feat2       # add two worktrees at once
#   gtr rm feature0              # remove the worktree directory
#   gtr cd feature0              # jump into the worktree directory
#   gtr claude feature0          # run `claude` while inside that worktree
#

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#!/usr/bin/env zsh
# Multi-project worktree manager with Claude support
# 
# ASSUMPTIONS & SETUP:
# - Your git projects live in: ~/projects/
# - Worktrees will be created in: ~/projects/worktrees/<project>/<branch>
# - New branches will be named: <your-username>/<feature-name>
#
# DIRECTORY STRUCTURE EXAMPLE:
# ~/projects/

Gerst20051

require 'socket'
require 'rack'
require 'rack/lobster'

app = Rack::Lobster.new
server = TCPServer.new 5678

while session = server.accept
  request = session.gets
  puts request

Gerst20051

/**
*
*  Base64 encode / decode
*  http://www.webtoolkit.info/
*
**/
 
var Base64 = {
 
	// private property

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How To Install Different JDK Versions on MacOS with Homebrew

Keywords: Java, JDK (Java Development Kit), MacOS, Homebrew, Specific Version

This how-to guide covers how to install different versions of the JDK on MacOS with Homebrew.

Table of Contents

• Preface
• This Guide Favors OpenJDK

Gerst20051

function mapValues(obj, fn) {
  return Object.keys(obj).reduce((result, key) => {
    result[key] = fn(obj[key], key);
    return result;
  }, {});
}

function pick(obj, fn) {
  return Object.keys(obj).reduce((result, key) => {
    if (fn(obj[key])) {

Gerst20051

# My take on Mike's source_for method.
# (see http://pragmaticstudio.com/blog/2013/2/13/view-source-ruby-methods)
#
# (1) I named it 'src' rather than source_for (ok, I'm a lazy typer).
# (2) The edit function was broken out as a separate function.
# (3) The edit function is for emacs
# (4) If the method is not defined on the object, and the object 
#     is a class, then see if it is an instance method on the class.
#
# The fourth point allows my to say:

Gerst20051

import hashlib, struct, codecs
 
ver = 2
prev_block = "000000000000000117c80378b8da0e33559b5997f2ad55e2f7d18ec1975b9717"
mrkl_root = "871714dcbae6c8193a2bb9b2a69fe1c0440399f38d94b3a0f1b447275a29978a"
time_ = 0x53058b35 # 2014-02-20 04:57:25
bits = 0x19015f53
 
# https://en.bitcoin.it/wiki/Difficulty
exp = bits >> 24

Gerst20051

import hashlib, struct
 
ver = 2
prev_block = "000000000000000117c80378b8da0e33559b5997f2ad55e2f7d18ec1975b9717"
mrkl_root = "871714dcbae6c8193a2bb9b2a69fe1c0440399f38d94b3a0f1b447275a29978a"
time_ = 0x53058b35 # 2014-02-20 04:57:25
bits = 0x19015f53
 
# https://en.bitcoin.it/wiki/Difficulty
exp = bits >> 24

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System Design Cheatsheet

Picking the right architecture = Picking the right battles + Managing trade-offs

Basic Steps

1. Clarify and agree on the scope of the system

• User cases (description of sequences of events that, taken together, lead to a system doing something useful)
  • Who is going to use it?
  • How are they going to use it?