debug-0.0: README.md
# Shake [](https://hackage.haskell.org/package/debug) [](https://www.stackage.org/package/debug) [](https://travis-ci.org/ndmitchell/debug) [](https://ci.appveyor.com/project/ndmitchell/debug)
Module for debugging Haskell programs. To use, take the functions that you are interested in debugging, e.g.:
```haskell
module QuickSort(quicksort) where
import Data.List
quicksort :: Ord a => [a] -> [a]
quicksort [] = []
quicksort (x:xs) = quicksort lt ++ [x] ++ quicksort gt
where (lt, gt) = partition (<= x) xs
```
Turn on the `TemplateHaskell` and `ViewPatterns` extensions, import `Debug`, indent your code and place it under a call to `debug`, e.g.:
```haskell
{-# LANGUAGE TemplateHaskell, ViewPatterns #-}
module QuickSort(quicksort) where
import Data.List
import Debug
debug [d|
quicksort :: Ord a => [a] -> [a]
quicksort [] = []
quicksort (x:xs) = quicksort lt ++ [x] ++ quicksort gt
where (lt, gt) = partition (<= x) xs
|]
```
We can now run our debugger with:
```console
$ ghci QuickSort.hs
GHCi, version 8.2.1: http://www.haskell.org/ghc/ :? for help
[1 of 1] Compiling QuickSort ( QuickSort.hs, interpreted )
Ok, 1 module loaded.
*QuickSort> quicksort "haskell"
"aehklls"
*QuickSort> debugView
```
The call to `debugView` starts a web browser to view the recorded information, looking something like:
