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Diffstat (limited to 'src/Parser.hs')
| -rw-r--r-- | src/Parser.hs | 67 |
1 files changed, 67 insertions, 0 deletions
diff --git a/src/Parser.hs b/src/Parser.hs new file mode 100644 index 0000000..62eff14 --- /dev/null +++ b/src/Parser.hs @@ -0,0 +1,67 @@ +module Parser ( + parse, +) where + +import qualified Data.Map as M +import qualified Data.List as L +import Control.Monad.Except +import Text.Regex.TDFA +import Utils + +validateBalance :: [String] -> [AST] -> LContext [AST] +validateBalance allowed asts = do + when (ASTSymbol "(" `elem` asts && "(" `notElem` allowed) + $ throwL "unbalanced function call" + when (ASTSymbol "[" `elem` asts && "[" `notElem` allowed) + $ throwL "unbalanced vector" + when (ASTSymbol "{" `elem` asts && "{" `notElem` allowed) + $ throwL "unbalanced hash map" + return asts + +parseToken :: String -> AST +parseToken token + | isInteger token = ASTInteger (read token) + | isDouble token = ASTDouble (read token) + | isString token = ASTString $ removeQuotes token + | isBoolean token = ASTBoolean $ asBoolean token + | otherwise = ASTSymbol token + where + integerRegex = "^-?[[:digit:]]+$" + isInteger :: String -> Bool + isInteger t = t =~ integerRegex + doubleRegex = "^-?[[:digit:]]+(\\.[[:digit:]]+)?$" + isDouble :: String -> Bool + isDouble t = t =~ doubleRegex + isString t = "\"" `L.isPrefixOf` t + removeQuotes s = drop 1 s $> take (length s - 2) + isBoolean t = t `elem` ["true", "false"] + asBoolean t = if t == "true" then True else False + +_parse :: [AST] -> [String] -> LContext [AST] +_parse acc' [] = do + acc <- validateBalance [] acc' + return $ reverse acc +_parse acc (")":rest) = do + let children' = takeWhile (/= ASTSymbol "(") acc + children <- validateBalance ["("] children' + let fnCall = ASTFunctionCall (reverse children) + let newAcc = fnCall : drop (length children + 1) acc + _parse newAcc rest +_parse acc ("]":rest) = do + let children' = takeWhile (/= ASTSymbol "[") acc + children <- validateBalance ["["] children' + let vec = ASTVector (reverse children) + let newAcc = vec : drop (length children + 1) acc + _parse newAcc rest +_parse acc ("}":rest) = do + let children' = takeWhile (/= ASTSymbol "{") acc + children <- validateBalance ["{"] children' + pairs <- asPairsM $ reverse children + let vec = ASTHashMap (M.fromList pairs) + let newAcc = vec : drop (length children + 1) acc + _parse newAcc rest +_parse acc (token:rest) = + _parse (parseToken token : acc) rest + +parse :: [String] -> LContext [AST] +parse = _parse []
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