zeeshanlakhani

;; Deriving something like generators, but I didn't really feel like
;; doing exactly that.

;; It doesn't, for instance, support sending back into the generator

;; This applys a function across a range from 0 to x.
(define (apply-to-range f i x)
  (when (< i x)
    (f i)
    (apply-to-range f (+ 1 i) x)))

zeeshanlakhani

#Code from http://fmota.eu/, great!
class Monoid:
	def __init__(self, null, lift, op):
		self.null = null
		self.lift = lift
		self.op   = op

	def fold(self, xs):
		if hasattr(xs, "__fold__"):
			return xs.__fold__(self)

zeeshanlakhani

Testing Stateful Code

So far, all the properties we have written have tested stateless code. Stateless code is made up of pure functions and is inherently easier to test than stateful code with side effects. The chief problem with testing stateful code is that the input to output mapping depends on the current state of the program. Previous operations can cause the same function to return different output given the same input. Therefore, in order to test stateful code, our tests must maintain some state of their own. This state is known as the model state and is updated as part of the testing process.

zeeshanlakhani

(ns markerbot.core
 (:require [taoensso.timbre :as log]
           [clojure.data.json :as json]
           [clojure.string :as s]
           [clj-http.client :as client])
  (:import (java.net Socket)
           (java.io PrintWriter InputStreamReader BufferedReader))
  (:gen-class))

;; marksy

zeeshanlakhani

Erlang Tracing: more than you wanted to know

Rough Outline

• What can be traced?
• How can trace events be specified?
• "match specifications": twisty passages, all alike
• WTF, can I just use DTrace and drink my coffee/beer/whisky in peace?
• Trace delivery mechanisms: pick one of two

zeeshanlakhani

Latency Comparison Numbers
--------------------------
L1 cache reference                            0.5 ns
Branch mispredict                             5   ns
L2 cache reference                            7   ns             14x L1 cache
Mutex lock/unlock                            25   ns
Main memory reference                       100   ns             20x L2 cache, 200x L1 cache
Compress 1K bytes with Zippy              3,000   ns
Send 1K bytes over 1 Gbps network        10,000   ns    0.01 ms
Read 4K randomly from SSD*              150,000   ns    0.15 ms

zeeshanlakhani

/**
 * Creates an ArrayBuffer, converts the binary to a Uint8 Array, and
 * places the buffer in a DataView, which is needed to create a Blob
 **/
_makeBlob: function(binary) {
    var data = new ArrayBuffer(binary.length),
        mimeString = "text/plain",
        ui8a =  new Uint8Array(data, 0),
        dataView,
        blob;

zeeshanlakhani

import os, sys, glob
import cv
import math
import argparse

HAAR_CASCADE_FRONT = \
    "/usr/local/share/OpenCV/haarcascades/haarcascade_frontalface_alt2.xml"
HAAR_CASCADE_PROFILE = \
    "/usr/local/share/OpenCV/haarcascades/haarcascade_profileface.xml"

zeeshanlakhani

import os
import sys
import glob
import cv
import math
import argparse
from collections import OrderedDict

HAAR_CASCADE_FRONT = \
    "/usr/local/share/OpenCV/haarcascades/haarcascade_frontalface_alt2.xml"

zeeshanlakhani

_.mixin({

	capitalize: function(string) {
		return string.charAt(0).toUpperCase() + string.substring(1).toLowerCase();
	},

	startsWith: function(string, start) {
		return string.slice(0, start.length) == start;
	},