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mal/haskell/Core.hs
2015-01-09 16:16:53 -06:00

148 lines
3.7 KiB
Haskell

module Core
( ns )
where
import qualified Data.Map as Map
import Reader (read_str)
import Types
import Printer (_pr_str, _pr_list)
-- General functions
equal_Q args = case args of
[a, b] -> return $ if a == b then MalTrue else MalFalse
_ -> error $ "illegal arguments to ="
run_1 :: (MalVal -> MalVal) -> [MalVal] -> IO MalVal
run_1 f args = do
case args of
(x:[]) -> return $ f x
_ -> error $ "function takes a single argument"
run_2 :: (MalVal -> MalVal -> MalVal) -> [MalVal] -> IO MalVal
run_2 f args = do
case args of
(x:y:[]) -> return $ f x y
_ -> error $ "function takes a two arguments"
-- String functions
pr_str args = do
return $ MalString $ _pr_list True " " args
str args = do
return $ MalString $ _pr_list False "" args
prn args = do
putStrLn $ _pr_list True " " args
return Nil
println args = do
putStrLn $ _pr_list False " " args
return Nil
slurp args = do
case args of
([MalString path]) -> do
str <- readFile path
return $ MalString str
_ -> error $ "invalid arguments to slurp"
-- Numeric functions
num_op op args = case args of
[MalNumber a, MalNumber b] -> return $ MalNumber $ op a b
_ -> error $ "illegal arguments to number operation"
cmp_op op args = case args of
[MalNumber a, MalNumber b] ->
return $ if op a b then MalTrue else MalFalse
_ -> error $ "illegal arguments to comparison operation"
-- List functions
list args = do
return $ MalList args
-- Vector functions
vector args = do
return $ MalVector args
-- Hash Map functions
hash_map args = do
return $ MalHashMap $ Map.fromList $ _pairs args
-- Sequence functions
cons x Nil = MalList [x]
cons x (MalList lst) = MalList $ x:lst
cons x (MalVector lst) = MalList $ x:lst
concat1 a (MalList lst) = a ++ lst
concat1 a (MalVector lst) = a ++ lst
do_concat args = return $ MalList $ foldl concat1 [] args
nth args = do
case args of
(MalList lst):(MalNumber idx):[] ->
if idx < length lst then return $ lst !! idx
else error "nth: index out of range"
(MalVector lst):(MalNumber idx):[] ->
if idx < length lst then return $ lst !! idx
else error "nth: index out of range"
first (MalList lst) = if length lst > 0 then lst !! 0 else Nil
first (MalVector lst) = if length lst > 0 then lst !! 0 else Nil
rest (MalList lst) = MalList $ drop 1 lst
rest (MalVector lst) = MalList $ drop 1 lst
empty_Q Nil = MalTrue
empty_Q (MalList []) = MalTrue
empty_Q (MalVector []) = MalTrue
empty_Q _ = MalFalse
count Nil = MalNumber 0
count (MalList lst) = MalNumber $ length lst
count (MalVector lst) = MalNumber $ length lst
count _ = error $ "non-sequence passed to count"
ns = [
("=", _func equal_Q),
("pr-str", _func pr_str),
("str", _func str),
("prn", _func prn),
("println", _func println),
("read-string", _func (\[(MalString s)] -> read_str s)),
("slurp", _func slurp),
("<", _func $ cmp_op (<)),
("<=", _func $ cmp_op (<=)),
(">", _func $ cmp_op (>)),
(">=", _func $ cmp_op (>=)),
("+", _func $ num_op (+)),
("-", _func $ num_op (-)),
("*", _func $ num_op (*)),
("/", _func $ num_op (div)),
("list", _func $ list),
("list?", _func $ run_1 _list_Q),
("vector", _func $ vector),
("vector?", _func $ run_1 $ _vector_Q),
("hash-map", _func $ hash_map),
("map?", _func $ run_1 $ _hash_map_Q),
("cons", _func $ run_2 $ cons),
("concat", _func $ do_concat),
("nth", _func nth),
("first", _func $ run_1 $ first),
("rest", _func $ run_1 $ rest),
("empty?", _func $ run_1 $ empty_Q) ,
("count", _func $ run_1 $ count)]