ndmitchell

 TOT   INH   IND
51.0  47.4     -  Hint.Match readMatch (53)
12.0  12.0     -  Data.Generics.Uniplate.Internal.Data readCacheFollower (3)
10.3  10.2    .6  Language.Haskell.Exts parseFileContentsWithComments (53)
 8.7   7.5   7.5  Data.Generics.Uniplate.Internal.Data uniplateData (1377837)
99.9   5.2     -  MAIN MAIN (0)
 2.9   2.8   2.0  Data.Generics.Uniplate.Internal.Data descendBiData (109203)
 2.4   2.4     -  HSE.All runCpp (53)
 2.3   2.3   2.3  Data.Generics.Uniplate.Internal.Data typeKey (2721430)
 1.9   1.5   1.5  Data.Generics.Uniplate.Internal.Data fromOracle (1031785)

ndmitchell

	Thu Jun 01 08:33 2017 Time and Allocation Profiling Report  (Final)

	   hlint +RTS -P -RTS src

	total time  =        1.24 secs   (1242 ticks @ 1000 us, 1 processor)
	total alloc = 2,511,288,344 bytes  (excludes profiling overheads)

COST CENTRE                   MODULE                                %time %alloc  ticks     bytes

ndmitchell

{-# OPTIONS_GHC -O2 #-}
import Control.Monad
import Control.Exception
import System.Time.Extra

import Criterion.Main

type DList a = [a] -> [a]

dTo f = f []

ndmitchell

	Tue Jan 24 08:33 2017 Time and Allocation Profiling Report  (Final)

	   hlint +RTS -p -RTS src

	total time  =        2.27 secs   (2274 ticks @ 1000 us, 1 processor)
	total alloc = 42,443,280,112 bytes  (excludes profiling overheads)

COST CENTRE   MODULE                                %time %alloc

uniplateData  Data.Generics.Uniplate.Internal.Data   41.4   68.1

ndmitchell

Haskell can be written using nothing more than a text editor, and most popular editors include Haskell syntax highlighting out of the box. In addition, some editors can be enhanced to provide IDE-like features, using the tools listed below.

Intero (Emacs enhancement)

• Provides instant error feedback, completions, go to definition, applying suggestions, type of expression.
• Works with GHC 7.8 onwards, benefits from Stack.

ndmitchell

{-# LANGUAGE Rank2Types #-}

import qualified Core.IO as F
import qualified Core.String as F
import qualified Core.Array as F
import qualified Core.VFS as F
import qualified Data.ByteString.Lazy as LBS
import qualified Data.ByteString as BS
import Codec.Compression.GZip as GZip
import Codec.Archive.Tar as Tar

ndmitchell

Each key gets intern'd into an Id


Key :-> Id

Id :-> Status

ndmitchell

I suspect the below isn't a good idea, because the remember needs repeating lots of times for every user of a rule. The new design seems to eliminate these issues more cleanly, but it's an interesting point in the design space.

Rethinking Rules

The current Rule typeclass has a number of issues. It's a bit complex to use, it often results in more dependencies than you were hoping, it's hard to control. People often end up defining oracles instead or rules but then you don't get options for other things. This document attempts to rethink that.

Concept

Shake runs rules that produce values. These rules track the current state of the system (other rules) and external values (files on disk). Currently the value produced by a rule is tracked automatically. This is often awkward. Imagine we want:

ndmitchell

stack setup
stack install happy alex
stack exec -- pacman -S gcc binutils git automake-wrapper tar make patch --no-confirm
stack exec -- git clone --recursive git://git.haskell.org/ghc.git
cd ghc
stack exec -- git clone git://github.com/snowleopard/shaking-up-ghc shake-build
stack exec -- perl boot
stack exec -- bash configure --enable-tarballs-autodownload
stack build --stack-yaml=shake-build/stack.yaml --only-dependencies
stack exec  --stack-yaml=shake-build/stack.yaml -- shake-build/build.bat -j

ndmitchell

module Main(main) where

import Data.Maybe
import Data.List

-- Data table copied from https://matthewearl.github.io/2015/12/10/gchq-xmas-card/
width = 25
height = 25
rows = [