Skip to content

Instantly share code, notes, and snippets.

@stevecj
stevecj / yaml_value_extraction_benchmarks.rb
Last active August 29, 2015 13:57
Benchmarking of ways of extracting single value from large YAML map (e.g. ActiveRecord serialized data)
require 'yaml'
require 'benchmark'
def make_yaml_string(num_entries=500)
entry_nums = (0...num_entries).to_a
entry_nums.shuffle!
result = ''
entry_nums.each do |n|
result << "something_#{n}: #{Random.rand}\n"
end
@stevecj
stevecj / n-is-the-loneliest-number.txt
Last active September 10, 2015 15:02
(n) is the Loneliest Number
One is the loneliest number that you'll ever do
Two can be as bad as one, well it's the loneliest number since the number one
Three is really not so bad, but it can still be lonely, and that's really sad
Four is really no big deal, so if you think it's lonely, then you'd best get real
Five is practically a crowd, and if you're tryin' to think, it can seem really loud.
Five is the loneliest number
Five is the loneliest number
Five is the loneliest number since the number four dum dum-dum dum-dum
@stevecj
stevecj / require_limit_for_mysql_text.rb
Last active August 29, 2015 14:03
Require a :limit option for MySQL text columns created in Rails 3 app so don't unintentionally make 64K column that silently truncates.
# == config/initializers/require_limit_for_mysql_text.rb ==
# Fail when an attempt is made to specify a MySQL text
# columnn in a migration without providing a :limit value.
# This helps to prevent accidentally defining a 64K column
# (default) when a 16MB or 4GB coumn is desired.
# Note that MySQL silently truncates the data when it is
# too long for the column, so problems are only apparent
# later when attempting to retrieve the data (if then).
@stevecj
stevecj / colortest
Created July 29, 2014 16:50
ANSI color test written in Ruby
#!/usr/bin/env ruby
ColorNameSequence = %w[
Black
Red
Green
Yellow
Blue
Magenta
Cyan
@stevecj
stevecj / reversible_queue.rb
Last active August 29, 2015 14:10
ReversibleQueue: Works much like Ruby's native Queue, but provides an #undeq method, which Ruby's own Queue does not have
# Works much like Ruby's native Queue, but provides an #undeq
# method, which Ruby's own Queue does not have.
class ReversibleQueue
def initialize
@queue_array = []
@threads_waiting = []
@mutex = Mutex.new
end
# Push an object onto the tail of the queue
@stevecj
stevecj / gist:9ace6a70370f6d1a1511
Last active December 2, 2019 06:34
Ruby will destructure objects that are not arrays, but respond to #to_ary
S=Struct.new(:a,:b)
ss = [S.new(1,2), S.new(3,4)]
p ss.map{|a,b| "#{a} #{b}" }
# => ["#<struct S a=1, b=2> ", "#<struct S a=3, b=4> "]
class S ; def to_ary ; to_a ; end ; end
p ss.map{|a,b| "#{a} #{b}" }
# => ["1 2", "3 4"]
@stevecj
stevecj / flatten-it.rb
Last active March 30, 2016 08:49
Coding exercise: Flatten an array in Ruby w/o using `Array#flatten`
module ArrayUtils
def self.flatten(array, result=[])
array = Array(array)
array.each do |entry|
case entry
when Array
flatten entry, result
else
result << entry
end