Refactor Lib.hs

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 []
\ No newline at end of file