Invoking ghci with hackage modules
Hi all, a very basic question, that I cannot solve alone: How do I load modules from hackage into ghci ? Say, I have a module arrows.hs : {-# LANGUAGE Arrows #-} module Main where import Control.Arrow import Control.Monad import qualified Control.Category as Cat import Data.List import Data.Maybe import System.Random I get the error in ghci: % ghci arrows.hs GHCi, version 8.10.6: https://www.haskell.org/ghc/ :? for help [1 of 1] Compiling Main ( arrows.hs, interpreted ) arrows.hs:9:1: error: Could not find module ‘System.Random’ Use -v (or `:set -v` in ghci) to see a list of the files searched for. | 9 | import System.Random | ^^^^^^^^^^^^^^^^^^^^ Failed, no modules loaded. Prelude> System.Random is in the package "random" from hackage, where the other modules are in the package base. I cannot find a solution in the doku that works :-( Thanks for help!
Hi, With Stack:
stack ghci --resolver=lts-18.28 --package=random arrows.hs
You can use Stack's script feature to specify resolver and packages directly in the .hs file. See https://www.wespiser.com/posts/2020-02-02-Command-Line-Haskell.html for some examples. Cheers, Sylvain On 16/06/2022 01:39, Lists0 wrote:
Hi all,
a very basic question, that I cannot solve alone: How do I load modules from hackage into ghci ? Say, I have a module arrows.hs :
{-# LANGUAGE Arrows #-}
module Main where import Control.Arrow import Control.Monad import qualified Control.Category as Cat import Data.List import Data.Maybe import System.Random
I get the error in ghci:
% ghci arrows.hs GHCi, version 8.10.6: https://www.haskell.org/ghc/ :? for help [1 of 1] Compiling Main ( arrows.hs, interpreted )
arrows.hs:9:1: error: Could not find module ‘System.Random’ Use -v (or `:set -v` in ghci) to see a list of the files searched for. | 9 | import System.Random | ^^^^^^^^^^^^^^^^^^^^ Failed, no modules loaded. Prelude>
System.Random is in the package "random" from hackage, where the other modules are in the package base.
I cannot find a solution in the doku that works :-(
Thanks for help!
_______________________________________________ Beginners mailing list Beginners@haskell.org http://mail.haskell.org/cgi-bin/mailman/listinfo/beginners
if you're using stack, then indeed, as Sylvain said.
if not, this means that the ghci that is being used, and it's relevant
haskell does not have "random" installed. so for example if this is the
system installed one, install the relevant package with haskell's random
too.
On Thu, Jun 16, 2022 at 9:55 AM Sylvain Henry
Hi,
With Stack:
stack ghci --resolver=lts-18.28 --package=random arrows.hs
You can use Stack's script feature to specify resolver and packages directly in the .hs file. See https://www.wespiser.com/posts/2020-02-02-Command-Line-Haskell.html for some examples.
Cheers, Sylvain
On 16/06/2022 01:39, Lists0 wrote:
Hi all,
a very basic question, that I cannot solve alone: How do I load modules from hackage into ghci ? Say, I have a module arrows.hs :
{-# LANGUAGE Arrows #-}
module Main where import Control.Arrow import Control.Monad import qualified Control.Category as Cat import Data.List import Data.Maybe import System.Random
I get the error in ghci:
% ghci arrows.hs GHCi, version 8.10.6: https://www.haskell.org/ghc/ :? for help [1 of 1] Compiling Main ( arrows.hs, interpreted )
arrows.hs:9:1: error: Could not find module ‘System.Random’ Use -v (or `:set -v` in ghci) to see a list of the files searched for. | 9 | import System.Random | ^^^^^^^^^^^^^^^^^^^^ Failed, no modules loaded. Prelude>
System.Random is in the package "random" from hackage, where the other modules are in the package base.
I cannot find a solution in the doku that works :-(
Thanks for help!
_______________________________________________ Beginners mailing list Beginners@haskell.org http://mail.haskell.org/cgi-bin/mailman/listinfo/beginners
Beginners mailing list Beginners@haskell.org http://mail.haskell.org/cgi-bin/mailman/listinfo/beginners
--
With cabal repl, you can specify dependencies on Hackage with
--build-depends or -b for short, e.g.
cabal repl --build-depends random
Am Do., 16. Juni 2022 um 05:19 Uhr schrieb Lists0
Hi all,
a very basic question, that I cannot solve alone: How do I load modules from hackage into ghci ? Say, I have a module arrows.hs :
{-# LANGUAGE Arrows #-}
module Main where import Control.Arrow import Control.Monad import qualified Control.Category as Cat import Data.List import Data.Maybe import System.Random
I get the error in ghci:
% ghci arrows.hs GHCi, version 8.10.6: https://www.haskell.org/ghc/ :? for help [1 of 1] Compiling Main ( arrows.hs, interpreted )
arrows.hs:9:1: error: Could not find module ‘System.Random’ Use -v (or `:set -v` in ghci) to see a list of the files searched for. | 9 | import System.Random | ^^^^^^^^^^^^^^^^^^^^ Failed, no modules loaded. Prelude>
System.Random is in the package "random" from hackage, where the other modules are in the package base.
I cannot find a solution in the doku that works :-(
Thanks for help!
_______________________________________________ Beginners mailing list Beginners@haskell.org http://mail.haskell.org/cgi-bin/mailman/listinfo/beginners
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Sylvain Henry -
יהושע ולך