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module Base (Expr (..)
, Env (..)
) where
import Data.IORef
-- TODO: use LispNumber (src/Operators.hs) here instead of IntLiteral and FloatLiteral
-- TODO: add character literals: \#a \#b \#c \#space \#newline
-- TODO: add support for complex numbers, oct and hex numbers
data Expr = List [Expr]
| Vector [Expr]
| DottedList [Expr] Expr
| StringLiteral String
| IntLiteral Integer
| FloatLiteral Double
| BoolLiteral Bool
| Id String
| Function Fn
data Fn =
Fn {
params :: [String]
, body :: Expr
, environment :: Env
}
type Env = IORef [(String, IORef Expr)]
showLispList :: [Expr] -> String
showLispList = unwords . map show
instance Show Expr where
show (DottedList xs x) = "(" ++ showLispList xs ++ " . " ++ show x ++ ")"
show (List xs) = "(" ++ showLispList xs ++ ")"
show (Vector xs) = "#(" ++ showLispList xs ++ ")"
show (StringLiteral s) = "\"" ++ s ++ "\""
show (IntLiteral n) = show n
show (FloatLiteral n) = show n
show (BoolLiteral True) = "#t"
show (BoolLiteral False) = "#f"
show (Id i) = i
show (Function (Fn params body env)) = "<#procedure " ++ unwords params ++ ">"
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