timmytofu

# unregister broken GHC packages. Run this a few times to resolve dependency rot in installed packages.
# ghc-pkg-clean -f cabal/dev/packages*.conf also works.
function ghc-pkg-clean() {
  for p in `ghc-pkg check $* 2>&1  | grep problems | awk '{print $6}' | sed -e 's/:$//'`
  do
    echo unregistering $p; ghc-pkg $* unregister $p
  done
}

# remove all installed GHC/cabal packages, leaving ~/.cabal binaries and docs in place.

MohamedAlaa

tmux shortcuts & cheatsheet

start new:

tmux

start new with session name:

tmux new -s myname

hellerbarde

Latency numbers every programmer should know

L1 cache reference ......................... 0.5 ns
Branch mispredict ............................ 5 ns
L2 cache reference ........................... 7 ns
Mutex lock/unlock ........................... 25 ns
Main memory reference ...................... 100 ns             
Compress 1K bytes with Zippy ............. 3,000 ns  =   3 µs
Send 2K bytes over 1 Gbps network ....... 20,000 ns  =  20 µs
SSD random read ........................ 150,000 ns  = 150 µs

Read 1 MB sequentially from memory ..... 250,000 ns = 250 µs

henrik

tmux cheatsheet

As configured in my dotfiles.

start new:

tmux

start new with session name:

dupuy

Markdown and reStructuredText

GitHub supports several lightweight markup languages for documentation; the most popular ones (generally, not just at GitHub) are Markdown and reStructuredText. Markdown is sometimes considered easier to use, and is often preferred when the purpose is simply to generate HTML. On the other hand, reStructuredText is more extensible and powerful, with native support (not just embedded HTML) for tables, as well as things like automatic generation of tables of contents.