Question

我正在为Coursera的AI Planning课程编写一个Lispy PDDL解析器。

如何在Haskell中定义Lispy数据类型？

Answer 1

它看起来像Lispy，不是吗？

{-# LANGUAGE FlexibleInstances #-}

import Data.List

data S s = T s | S [S s] deriving (Eq)

instance Show (S String) where
 show (T s) = s
 show (S list) = "(" ++ (intercalate " " $ map show list) ++ ")"

sExpr = S [T "define",T "x",T "10",S [T "print",T "hello"],S []]

main = do
 putStrLn $ show sExpr

运行main的结果：

(define x 10 (print hello) ())

Answer 2

My Lispy PDDL Parser：

https://dl.dropbox.com/u/46434672/Code/LispyPddlParser.hs

DWR-operators.txt文件：

https://spark-public.s3.amazonaws.com/aiplan/resources/DWR-operators.txt

如何在Haskell中定义Lispy数据类型？

2 个答案: