nh2

Does realToFrac compile to a no-op for (CFloat <-> Float / CDouble <-> Double)?

(14:27:30) kosmikus: nh2: it'll be a noop in many situations. CDouble normally is a newtype wrapper around Double. There are GHC Rule pragmas that'll turn realToFrac between Double and CDouble into a realToFrac between Double and Double by applying the constructor. Applying the constructor is a no-op, and there's a Double/Double instance having id as implementation.
(14:28:17) kosmikus: nh2: that being said, it's known that while simple applications of newtype constructors are newtypes, that doesn't translate to all contexts (such as mapping the constructor over a datastructure, for example)
(14:28:55) FreeFull: kosmikus: realToFrac isn't part of a typeclass though, it is defined as realToFrac = fromRational . toRational
(14:30:37) kosmikus: FreeFull: hm, you're right, I've been looking at the wrong place. let's check again.
(14:32:38) nh2: kosmikus, FreeFull: I really hope that realToFrac has rewrite rules for Double/CDouble and

nh2

{-# LANGUAGE ScopedTypeVariables, BangPatterns #-}

-- Example of how forM_ [1..N] is slow

module Main (main) where

import Prelude hiding (read)
import Control.Monad
import Data.Vector ((!), Vector)
import qualified Data.Vector as V

nh2

{-# LANGUAGE FlexibleInstances, GeneralizedNewtypeDeriving #-}


newtype TimeUnit = TimeUnit Integer -- how many microseconds
  deriving (Eq, Show, Num)

instance Num (TimeUnit -> TimeUnit) where
  fromInteger n = \(TimeUnit scale) -> TimeUnit (n * scale)
  -- a + b = ... -- task for you

nh2

#!/bin/bash

# Creates a git repository called "testgit-generated"
# with two separate histories branching from the initial
# commit, each being 500 commits long.
# On top of each, we create 200 branches with one extra
# commit per branch.
# Should take around 30 seconds.

set -e

nh2

import Criterion.Main
import Data.List (sort)
import Data.Vector (Vector, fromList, unsafeThaw)
import qualified Data.Vector.Mutable as VM
import Data.Vector.Algorithms.Heap (select)
import Control.Monad.ST (runST)
import Data.Maybe (fromJust)

kSmallest1 :: Int -> [Int] -> Int

nh2

import Data.List (sort)
import qualified Data.Map as Map
import Distribution.PackDeps
import Control.Monad

main :: IO ()
main = do
  newest <- loadNewest

  let reverses = getReverses newest

nh2

{-# LANGUAGE BangPatterns, ScopedTypeVariables #-}

module Main (main) where

import Criterion.Main
import Control.Monad
import Data.Vector ((!), Vector)
import qualified Data.Vector as V
import qualified Data.Vector.Unboxed as U
import qualified Data.Vector.Unboxed.Mutable as UM

nh2

#include <stdio.h>

int main(int argc, char const *argv[])
{
  float f = 1.23;

  int i = * (int *) &f;
  printf("%d\n", i);

  float f2 = * (float *) &f;

nh2

import GHC.Generics
import Data.Typeable

deriving instance Show (f p) => Show (M1 i c f p)
deriving instance (Show (f p), Show (g p)) => Show ((f :*:g) p)
deriving instance (Show (f p), Show (g p)) => Show ((f :+:g) p)
deriving instance (Show c) => Show (K1 i c p)
deriving instance Show (V1 p)
deriving instance Show (U1 p)
deriving instance Show D

nh2

nh2: does `#if MIN_VERSION_base(4,7,0)` fail when using ghci / do I need to build with cabal? I'm trying to get my packages 7.8-ready
thoughtpolice: that macro is only defined by Cabal, IIRC. so yes, you do need cabal
nh2: thoughtpolice: is what they describe in https://github.com/hesselink/flock/pull/1 a valid workaround, using __GLASGOW_HASKELL__?
carter: nh2: yup, only in cbal
carter: yes
thoughtpolice: nh2: sure, __GLASGOW_HASKELL__ should be fine, since the accompanying version of base is fixed anyway
thoughtpolice: nh2: so you probably want something like '#if __GLASGOW_HASKELL__ >= 708'
thoughtpolice: nh2: but note __GLASGOW_HASKELL__ does not account for the minor version, so you can't distinguish base 4.7.0.0 from 4.7.1.0 for example
thoughtpolice: (although i think historically we've never bumped an update like that - only very minor bumps per release)
carter: thoughtpolice: edward just pointed out to me that GHC doesn't expose GHC minor version cpp