hrldcpr

One-line Tree in Python

Using Python's built-in defaultdict we can easily define a tree data structure:

def tree(): return defaultdict(tree)

That's it!

jboner

Latency Comparison Numbers (~2012)
----------------------------------
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        3 us
Send 1K bytes over 1 Gbps network       10,000   ns       10 us
Read 4K randomly from SSD*             150,000   ns      150 us          ~1GB/sec SSD

MohamedAlaa

tmux shortcuts & cheatsheet

start new:

tmux

start new with session name:

tmux new -s myname

tony4d

Download and install p4merge

• Download the perforce visual tool suite from here: http://www.perforce.com/perforce/downloads/index.html
• Copy only the p4merge.app file into your /Applications/ directory

Setup p4merge as a visual mergetool

willurd

Each of these commands will run an ad hoc http static server in your current (or specified) directory, available at http://localhost:8000. Use this power wisely.

Discussion on reddit.

Python 2.x

$ python -m SimpleHTTPServer 8000

benbalter

# Bulk convert shapefiles to geojson using ogr2ogr
# For more information, see http://ben.balter.com/2013/06/26/how-to-convert-shapefiles-to-geojson-for-use-on-github/

# Note: Assumes you're in a folder with one or more zip files containing shape files
# and Outputs as geojson with the crs:84 SRS (for use on GitHub or elsewhere)

#geojson conversion
function shp2geojson() {
  ogr2ogr -f GeoJSON -t_srs crs:84 "$1.geojson" "$1.shp"
}

rekkusu

require 'mkmf'
create_makefile('shellcode')

noonat

• Download and install VirtualBox.
• Download the CoreOS ISO
• Create a new VM in VirtualBox
  • For the OS, Other Linux, 64-bit should be fine
  • Give the VM 1gb of memory, like your physical hardware has.
  • Create a disk of whatever size you want. I made a VMDK file that could expand dynamically up to 8gb.
• Mount the ISO in the VM
  • Right click on the VM and click settings
• Go to the storage tab

jorisvandenbossche

Avaq

const I  = x => x
const K  = x => y => x
const A  = f => x => f (x)
const T  = x => f => f (x)
const W  = f => x => f (x) (x)
const C  = f => y => x => f (x) (y)
const B  = f => g => x => f (g (x))
const S  = f => g => x => f (x) (g (x))
const S_ = f => g => x => f (g (x)) (x)
const S2 = f => g => h => x => f (g (x)) (h (x))