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# Dave Jachimiakdavejachimiak

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Created Oct 3, 2014
tree-recursive solution to the counting change problem, pg. 41 SICP
View count-change.hs
 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
Last active Aug 29, 2015
SICP 1.11
View sicp-1.1.hs
 -- 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)
Created Oct 8, 2014
View sicp-1.12.hs
 -- 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 -- ...
Created Oct 20, 2014
ugh
View evented.js
 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;
Created Oct 25, 2014
View sicp1.17.hs
 -- ... -- ... -- [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
Created Oct 25, 2014
sicp 1.18
View sicp-1.18.hs
 -- [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
Created Aug 8, 2015
A lispy arithmetic REPL
View Makefile
 all: /usr/local/Cellar/bison/3.0.4/bin/bison lispcalc.y && gcc -lm -o lispcalc lispcalc.tab.c
Created Jun 9, 2012
:inclusion validator
View inclusion.rb
 class Resource < ActiveRecord::Base module Types ACTIVE = 'active' CANCELLED = 'cancelled' CEASED = 'ceased' DITCHED = 'ditched' MEDIA = 'media' ONE_TIME = 'one time' ARCHIVED = 'archived' end
Created Jun 27, 2012
Rails 3 join table migration