diff options
Diffstat (limited to 'src/Builtins.hs')
| -rw-r--r-- | src/Builtins.hs | 49 |
1 files changed, 49 insertions, 0 deletions
diff --git a/src/Builtins.hs b/src/Builtins.hs new file mode 100644 index 0000000..71401d8 --- /dev/null +++ b/src/Builtins.hs @@ -0,0 +1,49 @@ +module Builtins where + +import qualified Data.Map as M +import Control.Monad.Except +import Types + +builtinEnv :: Env +builtinEnv = M.fromList [ + ("+", builtinAdd2), + ("-", builtinSubtract2), + ("head", builtinHead), + ("tail", builtinTail) + ] + +builtinAdd2 :: AST +builtinAdd2 = + let outer ast1 = do + (ASTInteger a) <- assertIsASTInteger ast1 + let inner ast2 = do + (ASTInteger b) <- assertIsASTInteger ast2 + return $ ASTInteger $ a + b + return $ ASTFunction $ inner + in ASTFunction outer + +builtinSubtract2 :: AST +builtinSubtract2 = + let outer ast1 = do + (ASTInteger a) <- assertIsASTInteger ast1 + let inner ast2 = do + (ASTInteger b) <- assertIsASTInteger ast2 + return $ ASTInteger $ a - b + return $ ASTFunction $ inner + in ASTFunction outer + +builtinHead :: AST +builtinHead = + let outer ast = do + (ASTVector vec) <- assertIsASTVector ast + when (length vec == 0) $ throwError $ LException $ "head of empty vector" + return $ head vec + in ASTFunction outer + +builtinTail :: AST +builtinTail = + let outer ast = do + (ASTVector vec) <- assertIsASTVector ast + when (length vec == 0) $ throwError $ LException $ "tail of empty vector" + return $ ASTVector $ tail vec + in ASTFunction outer
\ No newline at end of file |