Hello World of PureScript-Python

Requisite

• Installation of PureScript Python, currently you have to install it from source with command stack install ..

• Python version >=3.5, and the installation of following Python packages:

  • purescripto
  • pysexpr

Notes

Currently, we cannot use Prelude and many other libraries.

Hence we use this src/Main.purs:

module Main where
data IO a
foreign import println :: forall a. a -> IO {}

main :: IO {}
main = println "hello world"

Main.js in src is only for IDE use. PureScript has an awesome IDE support within VSCode, and I bet you will be a fan of this IDE functions if you're also a Haskeller(you know why)..

You can remove Main.js if you don't want to enjoy the IDE.

Main.py is the Python FFI file.

Just use the purescript build tool spago(bundled in purescript releases), type spago run in the root of this project, you got

hello world

See Python package hello_world/hello_world to check the effect.

See configurations in spago.dhall, there're 2 crucial points:

1. remove dependencies = [ "console", "effect", ...], use dependencies = [] : List Text
2. add backend = "pspy"

Finally, we will give examples of customizing the name of generated Python package, and the search path of foreign files.