blob: c8d8d34f5115685699423cd2f074f1a002598c80 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
|
module Evaluator (
eval
) where
import Control.Monad.Except
import Error (LispError (..), LispResult (..),
unwrap)
import Operators
import Parser
import Text.ParserCombinators.Parsec
apply :: String -> [Expr] -> LispResult Expr
apply fn args =
case lookup fn primitives of
Just f -> f args
_ -> throwError $ UnknownFunction fn
eval :: Expr -> LispResult Expr
eval v@(StringLiteral s) = return v
eval v@(IntLiteral i) = return v
eval v@(BoolLiteral b) = return v
eval v@(FloatLiteral f) = return v
-- handle quotes as literals
eval (List[Id "quote", val]) = return val
eval (List (Id fn : args)) = mapM eval args >>= apply fn
-- handle bad forms
eval idk = throwError $ BadForm "lisk can't recognize this form" idk
|
