JoshCheek

# Backticks and %x make a string literal and implicitly pass it to the backticks method,
# so if we define backticks to be identity, then that makes then equal to normal string literals.
# Though in practice, I've always taken advantage of the implicit invocation instead of nooping it.
def `(str)
  str
end

# I'm ignoring different delimiters, on the percent literals.
# eg I consider %q(str) and %q[str] to be equivalent, because otherwise there'd
# probably be another 500 possibilities.

JoshCheek

# A potential way to deal with https://twitter.com/postmodern_mod3/status/1348330707420991497

# include it to get reasonable JSONability
module JsonCreatable
  def self.append_features(base)
    base.extend ClassMethods
    base.include InstanceMethods
  end

  module ClassMethods

JoshCheek

Can you redeem sed's honour?

The premise

Been doing coding challenges. One of them is a golfing challenge, and you can use bash, I've got a really good Ruby solution, but figured I could get it even shorter if I used sed.

JoshCheek

# https://www.codingame.com/clashofcode/clash/report/15311917e86988f7c91d80a62ec9bf1022c0607
# It's a multiplexer, first bits select an output bit from the remaining bits.
# Only one person actually figured it out, and the others seem to think that person is a bot, so :shrug:
DATA.read.split("\n\n").map(&:lines).each do |test|
  width, num_rows = test.shift.split.map(&:to_i)
  rows      = test.take(num_rows)
  expecteds = test.drop(num_rows).map(&:chomp)

  outputs = rows.map do |row|
    # first $width bits choose which of the remaining bits we select

JoshCheek

// EXPLANATION / CHALLENGE: https://vimeo.com/492391391

// The program in JavaScript: `for(let i=10; i; --i) console.log(i)`
// But THIS!! is the program in "lambda calculus JavaScript"!!!!

// Functoins that begin with a dollar sign cheat and use JS stuff
const $DIE = arg => { throw new Error("should not call!") }

// The rest of these cheat by assigning to constants instead of passing into variables,
// but none of them are self refferential, so that's just to make it easier to read

JoshCheek

require 'active_record'

# An in-memory sqlite database, this is configured in config/database.yml
# Note that you will need the `sqlite3` gem installed
ActiveRecord::Base.establish_connection adapter: 'sqlite3', database: ':memory:'

# The db schema and data which do not follow the Rails convention,
# these might come from the Python app
sqlite = ActiveRecord::Base.connection.raw_connection
sqlite.execute 'create table user(id integer primary key, name string)'

JoshCheek

# Simulating the thought experiment in this paper:
# https://en.chessbase.com/post/what-gender-gap-in-chess

def simulate(n:, samples: 100_000)
  sum, maxes = 0, 0
  samples.times do
    scores = n.times.map { rand 1..100 }
    maxes += scores.max
    sum   += scores.sum
  end

JoshCheek

def json_parse(json)
  success, index, _ws   = json_parse_optional_whitespace(0, json)
  success, index, value = json_parse_value(index, json)
  raise "Could not parse" unless success
  value
end

def json_parse_value(index, json)
  %I[
    json_parse_null

JoshCheek

module Consistency
  original = Enumerable.instance_method :reduce
  refine Enumerable do
    # I didn't actually check it against the real impl or docs or anything, but its something like this
    alias_method :inject, define_method(:reduce) { |*args, &block|
      block = args.pop if args.size == 2
      Enumerator.new do |y|
        original.bind(self).call(*args) { |l, r| y.yield r, l }
      end.each &block
    }

JoshCheek

def rot13(ascii_char)
  ascii_offset  = 65
  alphabet_size = 26
  full_index    = ascii_char.ord - ascii_offset
  cap_bit       = full_index & 0b100000
  half_index    = full_index & 0b011111
  rotated       = (half_index + alphabet_size/2) % alphabet_size
  (rotated + cap_bit + ascii_offset).chr
end