Fixed issue with lines starting with comma

A.csv

-Steven , Steve , Butcher
-Dudley , Dudley , Timms
-Gillian , Gillian , Carter
\ No newline at end of file

B.csv

-jian,shi
-andrew,sogokon
-julian,rathke
\ No newline at end of file

CSV.hs

@@ -2,6 +2,7 @@ module CSV where
 
 import System.IO
 import Data.List
+import Debug.Trace
 
 readCSV :: FilePath -> IO [[String]]
 readCSV fname = do
@@ -9,16 +10,19 @@ readCSV fname = do
     return $ readCSVString str
 
 readCSVString :: String -> [[String]]
-readCSVString whole = [splitElem ',' (line++" " )  | line <- splitElem '\n' whole]
-splitElem :: Eq a => a -> [a] -> [[a]]
-splitElem elem = split (/=elem)
+readCSVString whole = [split ',' (' ':line ++ " ")  | line <- split '\n' whole]
+split :: Eq a => a -> [a] -> [[a]]
 
-split :: (a -> Bool) -> [a] -> [[a]]
-split p l = case span p l of
-        ([], _) -> []
-        (match, []) -> [match]
-        (match, _:rem') -> match:split p rem'
+split c l = (\(l, _,  _) -> reverse $ map reverse l) $ head $ dropWhile notEnd $ iterate split_ ([], [], l)
+    where
+        split_ (la, wa, []) = (wa:la, [], [])
+        split_ (la, wa, c':l_tail) | c == c' = (wa:la, [], l_tail)
+            | otherwise = (la, c':wa, l_tail)
 
+        notEnd (_, [], []) = False
+        notEnd _= True
+
+split1 a = span (==a)
 print2DList :: [[String]] -> IO ()
 print2DList = putStrLn.toCSVString
 

P.csv

-1 ,5 ,4 ,
-2 , ,2 ,
-3 ,7 ,1 ,2
-4 ,8 , ,
\ No newline at end of file

P42.csv

-David , Beckham
-Pele ,
-Diego , Maradona
-Cristiano, Ronaldo
-Ronaldinho ,
\ No newline at end of file

Q.csv

-1 ,6 ,4 ,7
-2 ,8 ,5 ,3
-2 , , ,1
-4 , ,2 ,3
\ No newline at end of file

R.csv

-1 ,5 ,4 ,0
-2 , 0,2 ,0
-3 ,7 ,1 ,2
-4 ,8 , 0,0
\ No newline at end of file

S.csv

-1 ,6 ,4 ,7
-2 ,8 ,5 ,3
-2 ,0,0,1
-4 ,0,2 ,3
\ No newline at end of file

SampleSet.csv

-  hello  ,tree
-big ,apple
-hello,world
-he,good
-hello,good bye

sampleprogram.txt

-.in
-SampleSet:4
-
-.out
-let f = \(r) -> r[1] == "hello";
-filter[SampleSet](f);
\ No newline at end of file

solutions/pr1.cql

-.in
-A:2, # declare input files and their numbers of cols in .in section
-B:2
-
-.out # statements for the query are in .out section
-A x B; # returns the cartesian product of the two sets (conjunction)
\ No newline at end of file

solutions/pr2.cql

-.in
-A:3
-
-.out
-filter( \(r) -> r[1] == r[2]);
-map (\(r) -> r[3,1]);
\ No newline at end of file

solutions/pr3.cql

-.in
-P: 4,
-Q: 4
-
-.out
-P x Q;
-filter(\(r) -> r[1] == r[5]);
-let f = \(a,y) -> if (isEmpty(a)) then y else a;
-map (\(r) -> [r[1], f(r[2], r[6]), f(r[3], r[7]), f(r[4], r[8])]);
\ No newline at end of file

solutions/pr4.cql

-.in
-P42 :2
-
-.out
-filter (\(r) -> not(isEmpty(r[2]) ) );
\ No newline at end of file

solutions/pr5.cql

-.in
-A:1
-
-.out
-map{A}(\(r) -> [r[1],"0",r[1]] );
\ No newline at end of file