FsService - purs

Main.purs

module Main where

import Prelude

import Effect (Effect)
import Effect.Class (liftEffect)
import Effect.Aff (Aff, launchAff_)
import Node.FS.Aff as FS
import Node.Buffer as Buffer
import Node.Encoding (Encoding(..))

type Path = String

class Monad m <= FsService m where -- [1]
  exists :: Path -> m Boolean
  create :: Path -> String -> m Unit

initProject :: ∀ m.
  FsService m => -- [2]
  String -> m Unit
initProject projectName = do
  doesExist <- exists projectName -- [3]
  if doesExist
  then pure unit
  else create projectName "Generated content" -- [4]
  
instance affFsService :: FsService Aff where -- [1]
  exists path = FS.exists path
  create path content = do
    FS.mkdir path
    buff <- liftEffect $ Buffer.fromString "Yoo" UTF8
    FS.writeFile path buff

main :: Effect Unit
main = launchAff_ do
  initProject "my-awesome-project"