feat: read stdin

Author: IB004

lab-parser/src/JsonParser.hs

@@ -1,5 +1,6 @@
 module JsonParser (
     JsonValue(..),
+    json,
     jsonValue,
     jsonNull,
     jsonBool,
@@ -22,6 +23,8 @@ data JsonValue = JsonNull
                | JsonObject [(String, JsonValue)]
                deriving (Show, Eq)
 
+json = ws *> jsonValue <* ws
+
 jsonValue :: Parser JsonValue
 jsonValue =     jsonNull 
             <|> jsonBool 
@@ -45,8 +48,18 @@ jsonNumber = lstToInt <$> number
     where
     lstToInt nms = JsonNumber $ read $ map intToDigit nms
 
+simpleChar_ :: Parser Char
+simpleChar_ = satisfy ((&&) <$> (/= '"') <*> (/= '\\'))
+
+escapedChar_ :: Parser Char 
+escapedChar_ =  ('"' <$ string "\\\"") 
+            <|> ('\\' <$ string "\\\\")
+            <|> ('\n' <$ string "\\n") 
+            <|> ('\r' <$ string "\\r") 
+            <|> ('\t' <$ string "\\t") 
+
 stringLiteral :: Parser [Char]
-stringLiteral = char '"' *> (many $ satisfy (/= '"')) <* char '"'
+stringLiteral = char '"' *>  many (simpleChar_ <|> escapedChar_) <* char '"'
 
 jsonString :: Parser JsonValue
 jsonString =  JsonString <$> stringLiteral

lab-parser/src/Lib.hs

@@ -4,6 +4,38 @@ module Lib (
 
 import Parser
 import JsonParser
+import System.IO
 
 mainLoop :: IO ()
-mainLoop = putStrLn "mainLoop"
+mainLoop = do 
+    inp <- readStdin
+    putStrLn inp
+    case (runParser json inp) of
+        (Right (ast, rest)) -> putStrLn $ show ast
+        (Left err) -> putStrLn err
+    hFlush stdout 
+
+myLoop = do 
+    done <- isEOF
+    if done
+      then do 
+        putStrLn "Bye!"
+        hFlush stdout   
+      else do 
+        inp <- getLine
+        putStrLn inp
+        hFlush stdout 
+        myLoop
+
+readStdin :: IO String
+readStdin = readStdin_ ""
+
+readStdin_ :: String -> IO String
+readStdin_ acc = do
+    done <- isEOF
+    if done
+      then do
+        return acc
+      else do 
+        inp <- getLine
+        readStdin_ $ acc ++ "\n" ++  inp

lab-parser/src/Parser.hs

@@ -53,14 +53,13 @@ char :: Char -> Parser Char
 char c = Parser $ \inp ->
     case (runParser (char_ c) inp) of 
         (Left err) -> Left (err ++ ", expected '" ++ [c] ++ "'" ++ context inp )
-        result -> result 
-
+        result -> result
 
 digit :: Parser Int
 digit = digitToInt <$> satisfy isDigit
 
 ws :: Parser String
-ws = many (satisfy isSpace)
+ws = many (satisfy (\c -> isSpace c || c == '\xfeff'))
 
 string_ :: String -> Parser String
 string_ str = sequenceA $ map char str 
@@ -78,4 +77,4 @@ number :: Parser [Int]
 number = some digit 
 
 context :: String -> String
-context inp = " in " ++ take 10 inp
+context inp = ": " ++ take 20 inp