davejachimiak

countChange :: Integer -> [Integer] -> Integer
countChange amount denominations
    | null denominations || amount < 0 = 0
    | amount == 0 = 1
    | otherwise = countChange amount (tail denominations) + countChange (amount - head denominations) denominations

davejachimiak

-- SICP 1.11
--
-- A function f is defined by the rule that f(n) = n if n < 3 and
-- f(n) = f(n - 1) + 2f(n - 2) + 3f(n - 3) if n >= 3. Write a
-- procedure computes f by means of a recursive process.
--
f :: Integer -> Integer
f n
    | n < 3 = n
    | otherwise = f (n - 1) + 2 * f (n - 2) + 3 * f (n - 3)

davejachimiak

-- SICP 1.12
--
-- The following pattern of numbers is called Pascal's triangle.
--
--      1
--     1 1
--    1 2 1
--   1 3 3 1
--  1 4 6 4 1
--     ...

davejachimiak

var Evented;

Evented = {
  on: function(event, callback) {
    var _base;
    (_base = this.callbacks)[event] || (_base[event] = []);
    return this.callbacks[event].push(callback);
  },
  trigger: function(event) {
    var args, callbacks;

davejachimiak

-- ...
-- ...
-- [Assume your language doesn't have a multiplication function or
-- table. Given `double` and `half` functions,] design a
-- multiplication procedure that uses a logarithmic number of steps.

double :: Integer -> Integer
double x = x + x

halve :: Integer -> Integer

davejachimiak

-- [Design an *iterative* process for multiplying to integers that] uses a
-- logarithmic number of steps.

double :: Integer -> Integer
double x = x + x

halve :: Integer -> Integer
halve x = x `div` 2

multiply :: Integer -> Integer -> Integer

davejachimiak

all:
	/usr/local/Cellar/bison/3.0.4/bin/bison lispcalc.y && gcc -lm -o lispcalc lispcalc.tab.c 

davejachimiak

class Resource < ActiveRecord::Base
  module Types
    ACTIVE    = 'active'
    CANCELLED = 'cancelled'
    CEASED    = 'ceased'
    DITCHED   = 'ditched'
    MEDIA     = 'media'
    ONE_TIME  = 'one time'
    ARCHIVED  = 'archived'
  end

davejachimiak

class CreateCohabitantsNotifications < ActiveRecord::Migration
  def change
    create_table :cohabitants_notifications, :id => false do |t|
      t.string :cohabitant_id,   :null => false
      t.string :notification_id, :null => false
    end
  end
end

davejachimiak

class CreateCohabitantsNotifications < ActiveRecord::Migration
  def change
    create_join_table :cohabitants, :notifications
  end
end