Created
May 20, 2020 23:40
-
-
Save maciejsmolinski/189d00ec355017c21f85b2f1ae0ff2d5 to your computer and use it in GitHub Desktop.
Simple EDSL in PureScript
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
module Main where | |
import Data.Traversable (traverse_) | |
import Effect (Effect) | |
import Effect.Console (logShow) | |
import Prelude | |
data Expression | |
= Num Int | |
| Add Expression Expression | |
| Subtract Expression Expression | |
eval :: Expression -> Int | |
eval (Num a) = a | |
eval (Add a b) = (eval a) + (eval b) | |
eval (Subtract a b) = (eval a) - (eval b) | |
expressions :: Array Expression | |
expressions = | |
[ Num 1 -- 1 | |
, Add (Num 1) (Num 2) -- 1 + 2 | |
, Subtract (Add (Num 1) (Num 2)) (Num 2) -- (1 + 2) - 2 | |
] | |
main :: Effect Unit | |
main = traverse_ (logShow <<< eval) expressions |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment