ga2arch

<code_scheme name="TW" version="173">
  <ClojureCodeStyleSettings>{
  :cljs.core/as-&gt; :only-indent
  :cljs.core/assoc 0
  :cljs.core/cond-&gt; :only-indent
  :cljs.core/cond-&gt;&gt; :only-indent
  :cljs.core/defonce :only-indent
  :cljs.core/with-meta :only-indent
  :cljs.core.async/go :only-indent
  :cljs.core.async/go-loop :only-indent

ga2arch

This note explains how to build Postgres from source and setup to debug it using LLDB on a Mac. I used this technique to research this article:
http://patshaughnessy.net/2014/10/13/following-a-select-statement-through-postgres-internals

1. Shut down existing postgres if necessary - you don’t want to mess up your existing DB or work :)

$ ps aux | grep postgres
pat               456   0.0  0.0  2503812    828   ??  Ss   Sun10AM   0:11.59 postgres: stats collector process       
pat               455   0.0  0.0  2649692   2536   ??  Ss   Sun10AM   0:05.00 postgres: autovacuum launcher process       
pat               454   0.0  0.0  2640476    304   ??  Ss   Sun10AM   0:00.74 postgres: wal writer process       
pat               453   0.0  0.0  2640476    336   ??  Ss   Sun10AM   0:00.76 postgres: writer process       

ga2arch

{-# LANGUAGE GeneralizedNewtypeDeriving #-}

import Control.Monad.IO.Class
import Control.Monad.Trans.Class
import Prelude hiding (log)

--------------------------------------------------------------------------------
-- The API for cloud files.
class Monad m => MonadCloud m where
  saveFile :: Path -> Bytes -> m ()

ga2arch

# OS X temporary files that should never be committed
#
# c.f. http://www.westwind.com/reference/os-x/invisibles.html

.DS_Store

# c.f. http://www.westwind.com/reference/os-x/invisibles.html

.Trashes

ga2arch

#include <CoreServices/CoreServices.h>
#include <iostream>

void callback(
  ConstFSEventStreamRef stream,
  void *callbackInfo,
  size_t numEvents,
  void *evPaths,
  const FSEventStreamEventFlags evFlags[],
  const FSEventStreamEventId evIds[])

ga2arch

{-# LANGUAGE OverloadedStrings, ScopedTypeVariables #-}
module Main where 

import Data.ByteString (ByteString)
import System.IO.Streams (InputStream, OutputStream)
import Network.Http.Client
import Text.Printf (printf)

import qualified Data.ByteString as B
import qualified Data.ByteString.Char8 as C8

ga2arch

I like LYAH as a reference and cheat-sheet but I found it a little slow for learning Haskell.

Here's my recommended order for just learning Haskell:

http://yannesposito.com/Scratch/en/blog/Haskell-the-Hard-Way/ 80% completion here is fine if you feel your attention waning, the next thing will address hammering in things like functors and monads via typeclasses.

https://github.com/NICTA/course/ this will hammer in the lessons in a very direct form by forcing you to confront the challenges and lessons learned by the creators and community of Haskell itself. Doing the exercises here is critical for being fluent.

Real World Haskell is available online. (Thanks bos!)

ga2arch

13:15 < xQuasar> HASKELL IS FOR FUCKIN FAGGOTS. YOU'RE ALL A BUNCH OF FUCKIN
                 PUSSIES
13:15 < xQuasar> JAVASCRIPT FOR LIFE FAGS
13:16 < luite> hello
13:16 < ChongLi> somebody has a mental illness!
13:16 < merijn> Wow...I suddenly see the error of my ways and feel compelled to 
                write Node.js!
13:16 < genisage> hi
13:16 < luite> you might be pleased to learn that you can compile haskell to
               javascript now

ga2arch

-- simple unification for predicate logic

data AtomicFormula = Variable String |  -- single variable 
                     Function String [AtomicFormula] -- function with some args

instance Show AtomicFormula where       
         show (Variable a) = a
         show (Function f l) = f ++ (show l)

data Formula = And Formula Formula -- conjunction, not needed

ga2arch

; http://groups.google.com/group/clojure/browse_thread/thread/974e2c7f89e27231/5f4bff3e58dfa36f
; output images http://i.imgur.com/gSASS.png (square maze)
;               http://i.imgur.com/uEqaq.png (hex maze)

;; generic Wilson's algorithm implementation
(defn maze 
 "Returns a random maze carved out of walls; walls is a set of
  2-item sets #{a b} where a and b are locations.
  The returned maze is a set of the remaining walls."
 [walls]