Код к докладу "Нетрадиционное использование Ruby и PostgreSQL" http://www.slideshare.net/evtuhovich/ruby-postgresql

rmongo.rb

require 'rubygems'
require 'pg'
require 'yaml'

class DB
  def initialize(debug = true)
    @conn = PG::Connection.open()
    @debug = debug
  end

  def things
    @things ||= Collection.new('things', self)
  end

  def conn
    @conn
  end

  def exec(query)
    puts query if @debug
    if @timing
      start = Time.now
    end
    res = @conn.exec query
    if @timing
      puts Time.now - start
    end

    res
  end

  def timing=(value)
    @timing = value
  end

  def debug=(value)
    @debug = value
  end
end

class Collection
  def initialize(name, db)
    @name = name
    @db = db
  end

  def insert(obj)
    serialize = obj.to_yaml
    @db.exec("INSERT INTO #{@name}(value) VALUES('#{@db.conn.escape_string(serialize)}')")
  end

  def count(conditions = {})
    query = "SELECT count(*) FROM #{@name}"

    cond = []
    conditions.each do | k, v|
      cond << "rmongorb_get_key('#{k}'::text, value) = '#{v}'"
    end

    unless cond.empty?
      query += ' WHERE ' + cond.join(' AND ')
    end

    @db.exec(query)[0]["count"].to_i
  end

  def find(conditions = {}, options = {})
    query = "SELECT * FROM #{@name}"

    cond = []
    conditions.each do | k, v|
      cond << "rmongorb_get_key('#{k}'::text, value) = '#{v}'"
    end

    unless cond.empty?
      query += ' WHERE ' + cond.join(' AND ')
    end

    if limit = options[:limit] || 30
      query += " LIMIT #{limit}"
    end

    if offset = options[:offet]
      query += " OFFSET #{offset}"
    end

    res = @db.exec(query)

    res.inject([]) do |result, tuple|
      value = YAML.load(tuple['value'])
      value['id'] = tuple['id']
      result << value
      result
    end
  end

  def ensureIndex(keys)
    keys.each do |k, v|
      query = "CREATE INDEX ON #{@name} (rmongorb_get_key('#{k}'::text, value))"

      @db.exec query
    end
  end
end

def db()
  @db ||= DB.new
  @db
end

=begin
CREATE OR REPLACE FUNCTION rmongorb_get_key(key text, value text) RETURNS text AS '
  require "yaml"
  obj = YAML.load(value)
  obj[key]
' LANGUAGE 'plruby' IMMUTABLE;
=end

serpinski.vim

function! Serpinski()
ruby << EOF
def draw(arr, x, y)
  arr[x][y] = '*'
end

def carpet(arr, size, x, y)
  if size == 1
    draw(arr, x, y)
  else
    new_size = size / 3
    carpet(arr, new_size, x, y)
    carpet(arr, new_size, x + new_size, y)
    carpet(arr, new_size, x + new_size * 2, y)
    carpet(arr, new_size, x, y + new_size)
    carpet(arr, new_size, x + new_size * 2, y + new_size)
    carpet(arr, new_size, x, y + new_size * 2)
    carpet(arr, new_size, x + new_size, y + new_size * 2)
    carpet(arr, new_size, x + new_size * 2, y + new_size * 2)
  end
end

arr = Array.new(27) { Array.new }
carpet(arr, 27, 0, 0)

arr.each_with_index do |line, i|
  l = line.map { |e| e.nil? ? ' ' : e }
  Vim::Buffer.current.append(Vim::Buffer.current.line_number + i, l.join(''))
end
EOF
endfunction