Haskell Stack Tutorial

• You can specify your resolver and package names inside myproject.cabal file.
• stack build will automatically download the packages to stack project. It is like Java Maven build.

Home brew it on your MacOS

brew update
brew install haskell-stack
# you might need to relink the stack symbol links
rm /usr/local/bin/stack
brew link --overwrite haskell-stack

Find out the location of stack and check your stack version

which stack
# /usr/local/bin/stack
stack --version
# /usr/local/Cellar/haskell-stack/1.9.3:

Create new project with Stack called myproject

stack new myproject simple

Download GHC for your project, it will take a while to download and it will not interfere your local GHC.

stack setup

Build Your Hello World

stack build

Run your project

stack exec myproject

Add time package to your build. myproject.cabal

# myproject.cabal
executable myproj
hs-source-dirs:      src
main-is:             Main.hs
default-language:    Haskell2010
build-depends:       base >= 4.7 && < 5,
                     time

Now we can use functions(e.g. getCurrentTime) from time package

import Data.Time
main::()
main = do
     time <- getCurrentTime
     putStrLn (show time)

• stack build and stack exec myproject

Try to figure out how to use your own module on Stack.

• It seems to me you have to put your modules under src inside .cabal file.
• You can use symbol link. e.g.

cd src && ln -s $b/haskelllib/AronModule.hs AronModule.hs

# myproject.cabal
hs-source-dirs:  src

Use different resolver Long Term Supported 12.13 ghc-8.4.3 in file: stack.yaml

-- ghc 8.4.3
stack new myproject --resolver=12.13 simple
-- check your stack.yaml