Ghc Alternatives

Reviews and mentions

• Status of Record Dot Syntax?
  reddit.com/r/haskell | 2021-10-08

  Thanks, it seems to be implemented in 9.2.1 with the extensions OverloadedRecordDot and OverloadedRecordUpdate. It seems that GHC 9.2.1 is at stage "RC1": https://github.com/ghc/ghc/tags

• Variable not in scope error
  reddit.com/r/haskellquestions | 2021-09-26

  % ghci scratch.hs GHCi, version 8.8.4: https://www.haskell.org/ghc/ :? for help Loaded GHCi configuration from /home/bss/.ghc/ghci.conf [1 of 1] Compiling Main ( scratch.hs, interpreted ) Ok, one module loaded. (0.05 secs,)

  reddit.com/r/haskell | 2021-09-26

  $ cat a.hs module Main where foo :: Int foo = 42 $ cat b.hs foo :: Int foo = 42 $ ghci a.hs GHCi, version 8.10.4: https://www.haskell.org/ghc/ :? for help Loaded package environment from /home/username/.ghc/x86_64-linux-8.10.4/environments/default Loaded GHCi configuration from /home/username/git/dotfiles/.ghci [1 of 1] Compiling Main ( a.hs, interpreted ) a.hs:1:1: error: The IO action ‘main’ is not defined in module ‘Main’ | 1 | module Main where | ^ Failed, no modules loaded. Prelude> Leaving GHCi. $ ghci b.hs GHCi, version 8.10.4: https://www.haskell.org/ghc/ :? for help Loaded package environment from /home/username/.ghc/x86_64-linux-8.10.4/environments/default Loaded GHCi configuration from /home/username/git/dotfiles/.ghci [1 of 1] Compiling Main ( b.hs, interpreted ) Ok, one module loaded. *Main> Leaving GHCi. $

• Integer coordinate from String
  reddit.com/r/haskell | 2021-09-25

  GHCi, version 9.0.1: https://www.haskell.org/ghc/ :? for help ghci> import Data.Char ghci> ord 'H' 72 ghci> ord 'H' - ord 'A' 7 ghci> ord '3' - ord '0' 3

• Defining an Applicative instance on a GADT
  reddit.com/r/haskellquestions | 2021-09-11

  GHCi, version 8.8.4: https://www.haskell.org/ghc/ :? for help Loaded GHCi configuration from /home/bss/.ghc/ghci.conf GHCi> :set -XGADTs GHCi> :{ GHCi| data Foo a where GHCi| Bar1 :: Int -> Foo Int GHCi| Bar2 :: Float -> Foo Float GHCi| :} type role Foo nominal data Foo a where ... (0.00 secs, 0 bytes) GHCi> :set -XEmptyCase GHCi> :{ GHCi| instance Functor Foo where GHCi| fmap f x = case x of {} GHCi| :} (0.00 secs, 0 bytes)

• stack ghci --ghci-options="-v0" <<< 'reverse [1, 2, 3]' -v0 does not remove all the message from console?
  reddit.com/r/haskell | 2021-09-09

  ghci -v1 <<< 'reverse [1, 2, 3]' GHCi, version 8.10.6: https://www.haskell.org/ghc/ :? for help Prelude> [3,2,1] Prelude> Leaving GHCi.

• How to hide extra stuff in the GHCi prompt?
  reddit.com/r/haskell | 2021-09-09

  GHCi, version 8.10.7: https://www.haskell.org/ghc/ :? for help Loaded GHCi configuration from /home/natewind/.ghci Prelude λ>

• nth element from a list
  reddit.com/r/haskellquestions | 2021-09-01

  GHCi, version 8.6.5: http://www.haskell.org/ghc/ :? for help Prelude> :{ Prelude| nth _ [] = error "nth: empty list" Prelude| nth 0 (x:_) = x Prelude| nth n (_:xs) = nth (n - 1) xs Prelude| :} Prelude> nth 3 [1,4,5,9,8] 9 Prelude> nth k l = if k == 1 then head l else nth (k - 1) (tail l) Prelude> nth 3 [1,4,5,9,8] 5

• Fragen zum Informatik Studium
  reddit.com/r/rwth | 2021-08-21

  Hierfür wird der Glasgow Haskell Compiler (GHC) genutzt: https://www.haskell.org/ghc/

• Help with understanding some Haskell questions for uni
  reddit.com/r/learnprogramming | 2021-08-18

  GHCi, version 8.4.4: http://www.haskell.org/ghc/ :? for help Prelude> :t 20:[2+0] 20:[2+0] :: Num a => [a] Prelude> :t (2.0, "2.0") (2.0, "2.0") :: Fractional a => (a, [Char]) Prelude> :t (id, map, sum) (id, map, sum) :: (Foldable t, Num a1) => (a2 -> a2, (a3 -> b) -> [a3] -> [b], t a1 -> a1)

• How to hide extra stuff before GHCi prompt in Stack?
  reddit.com/r/haskell | 2021-08-17

  /home/nate/.stack/programs/x86_64-linux/ghc-8.10.4/lib/ghc-8.10.4/bin/ghc: /lib/x86_64-linux-gnu/libtinfo.so.5: no version information available (required by /home/nate/.stack/programs/x86_64-linux/ghc-8.10.4/lib/ghc-8.10.4/bin/../haskeline-0.8.0.1/libHShaskeline-0.8.0.1-ghc8.10.4.so) /home/nate/.stack/programs/x86_64-linux/ghc-8.10.4/lib/ghc-8.10.4/bin/ghc: /lib/x86_64-linux-gnu/libtinfo.so.5: no version information available (required by /home/nate/.stack/programs/x86_64-linux/ghc-8.10.4/lib/ghc-8.10.4/bin/../ghc-8.10.4/libHSghc-8.10.4-ghc8.10.4.so) /home/nate/.stack/programs/x86_64-linux/ghc-8.10.4/lib/ghc-8.10.4/bin/ghc: /lib/x86_64-linux-gnu/libtinfo.so.5: no version information available (required by /home/nate/.stack/programs/x86_64-linux/ghc-8.10.4/lib/ghc-8.10.4/bin/../terminfo-0.4.1.4/libHSterminfo-0.4.1.4-ghc8.10.4.so) GHCi, version 8.10.4: https://www.haskell.org/ghc/ :? for help Loaded GHCi configuration from /home/nate/.ghci Prelude λ>

• I want `coerce` to make my newtype problems disappear. It stubbornly refuses.
  reddit.com/r/haskell | 2021-07-13

  $ ghci -XImpredicativeTypes GHCi, version 9.3.20210504: https://www.haskell.org/ghc/ :? for help ghci> import Data.Coerce ghci> newtype Foo = Foo { unFoo :: Char } ghci> newtype Bar = Bar { unBar :: String } ghci> somePolymorphicFunc :: Int -> a -> [a] -> [a]; somePolymorphicFunc = undefined ghci> import Control.Monad.State.Lazy ghci> :t \x y -> modify (coerce somePolymorphicFunc x y) \x y -> modify (coerce somePolymorphicFunc x y) :: (Coercible p1 Int, Coercible s [a], Coercible a p2, MonadState s m) => p1 -> p2 -> m ()

• Does 3d modelling / 3d game engines require sine/cosine / distance
  reddit.com/r/gamedev | 2021-06-23

  $ ghci GHCi, version 8.8.4: https://www.haskell.org/ghc/ :? for help Prelude> 1/3 + 1/3 :: Rational 2 % 3

• The Levenshtein Distance in Production
  news.ycombinator.com | 2021-06-06

  GHC also uses Demarau-Levenshtein [0]. The fuzzy lookup function gets re-used for a couple places too (including whatever you encountered in GHCi).

  [0]: https://github.com/ghc/ghc/blob/25977ab542a30df4ae71d9699d01...

• Monthly Hask Anything (June 2021)
  reddit.com/r/haskell | 2021-06-02

  % ghci GHCi, version 8.8.4: https://www.haskell.org/ghc/ :? for help Loaded GHCi configuration from /home/bss/.ghc/ghci.conf GHCi> data Job = MkJob { state :: Int } deriving Show data Job = ... GHCi> MkJob 42 MkJob {state = 42} GHCi> it{state=69} MkJob {state = 69} GHCi> it { state = 420 } MkJob {state = 420}