From c1713b4ea6c542fa2fe0d66b51c5b7b27fedf57a Mon Sep 17 00:00:00 2001 From: Jan Tuomi Date: Tue, 4 Oct 2022 15:21:56 +0300 Subject: Add import! --- src/Evaluator.hs | 227 ------------------------------------------------------- 1 file changed, 227 deletions(-) delete mode 100644 src/Evaluator.hs (limited to 'src/Evaluator.hs') diff --git a/src/Evaluator.hs b/src/Evaluator.hs deleted file mode 100644 index b7b792b..0000000 --- a/src/Evaluator.hs +++ /dev/null @@ -1,227 +0,0 @@ -{-# LANGUAGE LambdaCase #-} -module Evaluator ( - evaluate, -) where - -import qualified Data.Map as M -import qualified Data.List as L -import Data.Function ( on ) -import Control.Monad.Reader -import Control.Monad.Except ( catchError ) -import Utils --- import Debug.Trace - -type Depth = Int - -_curryCall :: Env -> [AST] -> LFunction -> LContext AST -_curryCall _ [] f = return $ (makeNonsenseAST $ ASTFunction f) -_curryCall env (arg:[]) f = f env arg -_curryCall env (arg:rest) f = do - g <- _curryCall env rest f - case astNode g of - ASTFunction f' -> f' env arg - other -> throwL (astPos g) $ "cannot call value " ++ show other ++ " as a function" - -curryCall :: Env -> [AST] -> LFunction -> LContext AST -curryCall env [] f = f env (makeNonsenseAST ASTUnit) -curryCall env args f = _curryCall env args f - -traverseAndReplace :: String -> AST -> AST -> AST -traverseAndReplace param arg ast@AST { astNode = ASTSymbol sym } - | sym == param = arg - | otherwise = ast -traverseAndReplace param arg ast@AST { astNode = ASTFunctionCall body } = - ast { astNode = ASTFunctionCall $ (map (traverseAndReplace param arg) body) } -traverseAndReplace param arg ast@AST { astNode = ASTVector vec } = - ast { astNode = ASTVector $ (map (traverseAndReplace param arg) vec) } -traverseAndReplace param arg ast@AST { astNode = ASTHashMap hmap } = - ast { astNode = ASTHashMap $ M.assocs hmap - $> L.concatMap (\(a, b) -> [a, b]) - .> map (traverseAndReplace param arg) - .> asPairs .> M.fromList } -traverseAndReplace _ _ other = other - -foldSymValPairs :: [(String, AST)] -> AST -> AST -foldSymValPairs [] body = body -foldSymValPairs ((sym, val):rest) body = - let replacedRestVals = map (snd .> traverseAndReplace sym val) rest - replacedRest = zip (map fst rest) (replacedRestVals) - replacedBody = traverseAndReplace sym val body - in foldSymValPairs replacedRest replacedBody - -letArgsToSymValPairs :: Depth -> Env -> [AST] -> LContext (String, AST) -letArgsToSymValPairs d env args = - case args of - [AST { astNode = ASTSymbol symbol' }, value'] -> do - (_, evaledValue) <- evaluate d env value' - return (symbol', evaledValue) - [AST { astNode = ASTSymbol "lazy" }, AST { astNode = ASTSymbol symbol' }, value'] -> do - return (symbol', value') - other -> throwL (astPos $ head other) $ "let! called with invalid args " ++ show other - -defineUserFunction :: Depth -> AST -> [AST] -> LContext LFunction -defineUserFunction d AST { astNode = ASTSymbol param } exprs = return fn where - fn :: LFunction - fn env arg = do - let replacedExprs = map (traverseAndReplace param arg) exprs - let letExprs = take (length exprs - 1) replacedExprs - letSymValPairs <- letExprs - $> mapM (\case AST { astNode = ASTFunctionCall v } -> return $ drop 1 v - ast -> throwL (astPos ast) $ "unreachable: map letExprs, ast: " ++ show ast) - .> fmap (mapM $ letArgsToSymValPairs d env) .> join - let body = head $ drop (length exprs - 1) replacedExprs - let newBody = traverseAndReplace param arg body - $> foldSymValPairs letSymValPairs - (_, ret) <- evaluate d env newBody - return ret - -defineUserFunction _ param exprs = throwL (astPos param) - $ "unreachable: defineUserFunction, param: " ++ show param ++ ", exprs: " ++ show exprs - -defineUserFunctionWithLetExprs :: Depth -> [AST] -> [AST] -> LContext LFunction -defineUserFunctionWithLetExprs d [] exprs = - -- the position info is nonsensical, but it should never get read anyway - defineUserFunction d (makeNonsenseAST $ ASTSymbol "unit") exprs -defineUserFunctionWithLetExprs d (param:[]) exprs = - defineUserFunction d param exprs -defineUserFunctionWithLetExprs d (AST { astNode = ASTSymbol param }:rest) exprs = return fn where - fn :: LFunction - fn _ arg = do - let newExprs = map (traverseAndReplace param arg) exprs - ret <- defineUserFunctionWithLetExprs d rest newExprs - -- the returned AST will not have the correct position info, but that's fine - -- because the info is overridden in evaluateFunctionDef anyway - return $ makeNonsenseAST $ ASTFunction $ ret -defineUserFunctionWithLetExprs _ (param:_) _ = throwL (astPos $ param) - $ "unreachable: defineUserFunctionWithLetExprs, param: " ++ show param - -evaluateFunctionDef :: Depth -> Env -> [AST] -> LContext (Env, AST) -evaluateFunctionDef d env asts = do - let defAst = head asts - args = tail asts - (params'', exprs) <- case args of - args' - | length args' < 2 -> - throwL (astPos defAst) $ "\\ called with " ++ show (length args) ++ " arguments" - | otherwise -> return $ (head args', tail args') - - AST { astNode = ASTVector params' } <- assertIsASTVector params'' - params <- mapM assertIsASTSymbol params' - - let shadowingParamM = L.find (astNode .> (\(ASTSymbol sym) -> sym) .> isParamNameShadowing) params - case shadowingParamM of - Just shadowingParam -> throwL (astPos shadowingParam) - $ "parameter is shadowing already defined symbol " ++ show (astNode shadowingParam) - Nothing -> return () - - let letExprs = take (length exprs - 1) exprs - let nonLetExprM = L.find (not . isLetAST) letExprs - case nonLetExprM of - Just nonLetExpr -> throwL (astPos nonLetExpr) - $ "non-let expression in function definition before body: " ++ show nonLetExpr - Nothing -> return () - - fn <- defineUserFunctionWithLetExprs d params exprs - return $ (env, defAst { astNode = ASTFunction fn }) - where - isLetAST AST { astNode = ASTFunctionCall (AST { astNode = ASTSymbol "let!" }:_) } = True - isLetAST _ = False - isParamNameShadowing name = M.member name env - -evaluateMatch :: Depth -> Env -> [AST] -> LContext (Env, AST) -evaluateMatch d env asts = do - let matchAst = head asts - args = tail asts - (actualExpr, rest) <- case args of - [] -> throwL (astPos matchAst) $ "match called with no arguments" - (_:[]) -> throwL (astPos matchAst) "empty match cases" - (a:b) -> return (a, b) - - pairs <- (asPairsM rest) `catchError` - (\_ -> throwL (astPos matchAst) $ "invalid number of arguments passed to match\n" - ++ "- matching on expr: " ++ show actualExpr ++ "\n" - ++ "- arguments: " ++ show rest) - - (_, evaledActual) <- evaluate d env actualExpr - ret <- matchPairs (actualExpr, evaledActual) pairs - return (env, matchAst { astNode = astNode ret }) - where - matchPairs :: (AST, AST) -> [(AST, AST)] -> LContext AST - matchPairs (actualExpr, evaledActual) [] = throwL (astPos actualExpr) - $ "matching case not found when matching on expression: " ++ show actualExpr - ++ " (actual value: " ++ show evaledActual ++ ")" - matchPairs (actualExpr, evaledActual) ((matcher, branch):restPairs) = do - (_, evaledMatcher) <- evaluate d env matcher - if evaledActual == evaledMatcher - then do - (_, ret) <- evaluate d env branch - return ret - else matchPairs (actualExpr, evaledActual) restPairs - -evaluateLet :: Depth -> Env -> [AST] -> LContext (Env, AST) -evaluateLet d env asts = do - let letAst = head asts - args = tail asts - when (d > 1) $ throwL (astPos letAst) $ "let! can only be called on the top level or in a function definition" - (symbol, value) <- letArgsToSymValPairs d env args - when (M.member symbol env) $ throwL (astPos letAst) $ "symbol already defined: " ++ symbol - let newEnv = M.insert symbol value env - return $ (newEnv, letAst { astNode = ASTUnit }) - -evaluateEnv :: Depth -> Env -> [AST] -> LContext (Env, AST) -evaluateEnv d env asts = do - let envAst = head asts - when (d > 1) $ throwL (astPos envAst) $ "env! can only be called on the top level or in a function definition" - let pairs = M.assocs env - let longestKey = L.maximumBy (compare `on` (length . fst)) pairs $> fst - let pad s = s ++ take (length longestKey + 4 - length s) (L.repeat ' ') - let rows = pairs $> map (\(k, v) -> pad k ++ show v) - liftIO $ mapM_ putStrLn rows - return (env, envAst { astNode = ASTUnit }) - -evaluateUserFunction :: Depth -> Env -> [AST] -> LContext (Env, AST) -evaluateUserFunction d env children = do - let fnAst = head children - args = tail children - (_, fnEvaled) <- evaluate d env fnAst - AST { astNode = (ASTFunction fn) } <- assertIsASTFunction fnEvaled - evaledArgs' <- mapM (evaluate d env) args - let evaledArgs = map snd evaledArgs' - doubleEvaledArgs' <- mapM (evaluate d env) evaledArgs - let doubleEvaledArgs = map snd doubleEvaledArgs' - result <- curryCall env (reverse doubleEvaledArgs) fn - -- maybe remove double eval here? can't remember why it was added - return (env, fnAst { astNode = astNode result }) - -evaluateSymbol :: Env -> AST -> LContext (Env, AST) -evaluateSymbol env ast@AST { astNode = ASTSymbol sym } = do - let val = M.lookup sym env - case val of - Just ast' -> return (env, ast') - Nothing -> throwL (astPos ast) $ "symbol " ++ sym ++ " not defined in environment" -evaluateSymbol _ ast = throwL (astPos ast) $ "unreachable: evaluateSymbol, ast: " ++ show ast - -evaluate :: Depth -> Env -> AST -> LContext (Env, AST) -evaluate d env AST { astNode = fnc@(ASTFunctionCall args@(x:_)) } = - do config <- ask - when (configPrintCallStack config) $ liftIO $ putStrLn $ "fn call: " ++ show fnc - case astNode x of - -- remember to add these as reseved keywords in Builtins! - ASTSymbol "\\" -> - evaluateFunctionDef (d + 1) env args - ASTSymbol "match" -> - evaluateMatch (d + 1) env args - ASTSymbol "let!" -> - evaluateLet (d + 1) env args - ASTSymbol "env!" -> - evaluateEnv (d + 1) env args - _ -> - evaluateUserFunction (d + 1) env args -evaluate _ env ast@AST { astNode = (ASTSymbol _) } = - evaluateSymbol env ast -evaluate d env ast@AST { astNode = (ASTVector vec) } = - do rets <- mapM (evaluate (d + 1) env) vec - let vec' = map snd rets - return $ (env, ast { astNode = ASTVector vec' }) -evaluate _ env other = - return (env, other) -- cgit v1.3