twolfe18’s gists

twolfe18 / New Java folks don't give a crap about old Java folks...

Last active February 19, 2016 19:11

	File f = new File("foo.txt");
	// You're not allowed to make a Path using raw strings,
	// that would be dangerous!
	Path p = FileSystems.getDefault().getPath("foo.txt");

	// Both of these type check :)
	f.getName().endsWith(".txt"); // true
	p.getFileName().endsWith(".txt"); // false

twolfe18 / SoABenchmark.java

Last active January 9, 2025 18:37

Does SoA (structure of arrays) beat AoS (array of structures) for Java?

	package sandbox;

	import java.util.Arrays;
	import java.util.Random;

	public class SoABenchmark {

	public static Random rand = new Random(9001);
	public static int NUM_LABELS = 10;
	public static Struct[] aos;

twolfe18 / gist:24d3ffcb332a9021460d

Last active August 29, 2015 14:17

One more reason I hate Java serialization...

	package sanbox;

	import java.io.File;
	import java.io.FileInputStream;
	import java.io.FileOutputStream;
	import java.io.ObjectInputStream;
	import java.io.ObjectOutputStream;
	import java.io.Serializable;

	public class SerializationBugMWE {

twolfe18 / playing_with_features.scala

Last active December 30, 2015 20:59

how to write neat feature functions in scala

	object IDontCare {

	def main(args: Array[String]) {
	example
	example2
	example3
	}


	def conjoin[I,P,O](f1: I => P, f2: I => P, compose: (P, P) => O): I => O = {

twolfe18 / gist:7207779

Last active December 26, 2015 20:19

optimization package interfaces

	trait Func0[V, P] {
	def value(p: P): V
	def dimension: Int
	}

	trait Func1[V, G, P] extends Func0[V, P] {
	def grad(p: P): G = compute(p)._2
	def compute(p: P): (V, G)
	}

twolfe18 / BetterLogging.scala

Last active December 22, 2015 11:18

a simple logging scheme in scala (that i can understand). i know there are a million logging frameworks, most of which probably have more features than this. but the way i see it, the time that it takes to learn one of those is about the same as the time it takes to write this one. the nice benefit of doing it this way is that i can always just …

	// NOTE: I actually made a mistake in this implementation
	// Logging needs to have a redirect with type Logging, not Logger
	// this is so that if a->b and b gets redirected, things logged via a.log()
	// actually get forwarded along (regardless of what came first: redirecting
	// b somewhere else or the call to a.log()).
	// the only thing to worry about is loops, but i'm willing to take that risk for now.
	// i have an implementation of this in Parma called Logging2

	import util.Random

twolfe18 / gist:5767545

Created June 12, 2013 17:49

private[this] vs private in scala


	// Foo.scala
	class Foo {
	private var i = 0
	private[this] var j = 0
	def getJ = j
	def iThing = i * i
	def jThing = j * j
	}

twolfe18 / sort-compression.txt

Created March 14, 2013 16:08

a hack i've been considering for compressing log files: sort them first.


	time gzip -c <orig >orig.gz
	real 0m0.311s
	user 0m0.289s
	sys 0m0.005s

	time bzip2 -c <orig >orig.bz2
	real 0m3.358s
	user 0m2.981s
	sys 0m0.367s

twolfe18 / google.py

Created January 23, 2012 02:32

command line tool to get URLs for a google search

	#!/usr/bin/python
	import sys, httplib, re

	if len(sys.argv) < 2:
	print 'provide a query'
	exit(0)

	c = httplib.HTTPConnection('www.google.com')
	c.request('GET', '/search?q=%s' % ('_'.join(sys.argv[1:])))
	r = c.getresponse()

twolfe18 / diag_len.py

Created January 3, 2012 16:43

get the dimensions of a video screen given its diagonal length

	import sys, math

	if len(sys.argv) != 2:
	print 'provide a diagonal length'
	exit(0)

	diag = float(sys.argv[1])

	# xx + yy = diag^2
	# x*ar = y

Travis Wolfe twolfe18