Added support for cartesian product

A.csv

+patryk,malinowski
+maram, jones
+jeffrey,sylvester

B.csv

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

Eval.hs

@@ -25,6 +25,9 @@ eval env expr = let (eval', evalFull') = (eval env, evalFull env) in case expr o
             RecordIndex -> let (Record recordData:Int index:_) = (map eval' args) in
                 recordData !! index
 
+            XProduct -> debug (show env) $ let ((Set l1): (Set l2):_) = map eval' inputSets in
+                Set $ [ x `concatRecord` y | x <- l1, y <- l2]
+
             --implement later
             --(Map) -> Set $ (map (\r -> FuncCall predicate [] [r]) inputRecords)
         (FuncDef setParams argParams body) -> eval newEnv body
@@ -49,3 +52,4 @@ evalFull = eval
 --evalFull env (Set xs) = Set (map (eval env) xs) -- evaluates expression fully (not just weak head normal form)
 --evalFull _ e = e
 --TODO implement properly
+concatRecord (Record r1) (Record r2) = Record (r1 ++ r2)
\ No newline at end of file

Interpreter.hs

@@ -2,6 +2,7 @@ import Types
 import Debug
 import Eval
 import System.IO
+import System.Environment
 import CSV
 import Lexer
 import Parser
@@ -11,7 +12,12 @@ parse :: String -> Program
 parse = parseSource.alexScanTokens
 --outline
 
-main = interpret "sampleprogram.txt"
+main = do
+    args <- getArgs
+    case args of
+        (srcname:_) -> interpret srcname
+        _ -> interpret "q1.txt"
+    
 
 interpret :: FilePath -> IO () -- the main function, takes in file name, prints out result
 interpret sourceFName = do

Lexer.x

@@ -26,8 +26,9 @@ false                           {\s -> TokenFalse }
 \)                             {\s -> TokenRightBracket }
 \;                             {\s -> TokenSemiCol }
 \\                            {\s -> TokenLambda }
---\,                             {\s -> TokenComma }
+\,                             {\s -> TokenComma }
 \.                             {\s -> TokenFullStop }
+x                                {\s -> TokenXProduct }
 $lower [$lower $digit \_ \']*   {\s -> TokenVarName s }
 $upper[$alpha]*                 {\s -> TokenSetName s }
 $digit+                         {\s -> TokenNat (read s) }
@@ -56,6 +57,7 @@ data Token =
     TokenComma          |
     TokenFullStop       |
     TokenInSet          |
+    TokenXProduct       |
     TokenOutSet
     deriving  (Eq, Show)
 }

Parser.y

@@ -29,6 +29,7 @@ import Types
 	'\\'            { TokenLambda }
 	','             { TokenComma  }
 	'.'             { TokenFullStop }
+	x				{ TokenXProduct }
 
 %right "->"
 %left "/=" "==" ';'
@@ -49,6 +50,8 @@ SetFuncCalls : SetFuncCall    {[$1]}
 SetFuncCall : filter '['SetName']' '('Func')' {FuncCall (PredefFunc Filter) [Var $3] [$6]}
 	| filter '('Func')' {FuncCall (PredefFunc Filter) [] [$3]}
 
+	| SetName x SetName	{FuncCall (PredefFunc XProduct) (map Var [$1, $3]) []}
+
 Func : '\\' '(' VarNames ')' "->" Expr {FuncDef [] $3 $6}