changed grammar rules according to June 12 discussion

todo: build parse tree

SQLPGrammar_new.y

@@ -30,8 +30,8 @@ SQLPProgram
 	{
 		printf("Input Query\n");
 		cons_cell *n = $1;
-        printf("Printing Tree\n");
-        print_cons_tree(n);
+		printf("Printing Tree\n");
+		print_cons_tree(n);
 	}
     ;
 
@@ -41,11 +41,13 @@ Query
 		printf("Union Query\n");
 		$$ = $1;
 	}
+	| Union_Query Limit Constant // todo: limit by or limit?
 	| Select_Query
 	{
 		printf("Select Query\n");
 		$$ = $1;
 	}
+	| Select_Query Limit Constant
 	;
 
 Select_Query
@@ -54,6 +56,7 @@ Select_Query
 		printf("SQLP Query\n");
 		$$ = create_proj_operator($2, $3);
 	}
+	| SELECT ELIM Select_List Body
 	;
 
 Elim
@@ -67,46 +70,44 @@ Limit
 	;
 
 Body
-	: FROM TablePath
+	: FROM TableList
 	{
 		printf("Body 1\n");
 		$$ =  $2;
 	}
-    | FROM TablePath WHERE Pred
+    | FROM TableList WHERE Pred
 	{
 		printf("Body 2\n");
 		$$ = create_eval_operator($4, $2);
 	}
 	;
 
-TablePath
+TableList
    	: TableIdentifier VarIdentifier
 	{
-		printf("Table path 1\n");
+		printf("TableList 1\n");
         $$ = create_rename_operator($1, $2);
     }
-   	| TableIdentifier VarIdentifier ',' TablePath
+   	| TableIdentifier VarIdentifier ',' TableList // keep right-recursive
 	{
-		printf("Table path 2\n");
+		printf("TableList 2\n");
     	$$ = create_cross_operator(create_rename_operator($1, $2), $4);
     }
    	;
 
+
 Union_Query
-	: Union_Query UNION Select_Query
+	: '(' Select_Query ')' UNION Union_Query
 	{
 		printf("Union query\n");
-   		$$ = create_union_all_operator($1, $3);
+   		$$ = create_union_all_operator($1, $3); // todo: create_union_operator
     }
+	| '(' Select_Query ')' UNIONALL Union_Query
+	: Select_Query
    	;
 
 Select_List
-	: STAR
-	{
-		printf("Select_List 1\n");
-		$$ = create_atom("STAR");
-	}
-	| Col
+	: Col
 	{
 		printf("Select_List 2\n");
 		$$ = create_rename_operator($1, NULL);
@@ -161,7 +162,7 @@ AttrIdentifier
 		$$ = create_var(yytext);
 	}
 
-Operator
+CompOperator
 	: EQ
 	{
 		printf("Operator EQ\n");
@@ -195,62 +196,23 @@ Operator
 	;
 
 Pred
-	: Col Operator Col
-	{
-		printf("Pred 1\n");
-		cons_cell* first_term = create_term($1);
-		cons_cell* second_term = create_term($3);
-		$$ = create_comp_operator($2, first_term, second_term, NULL);
-	}
-	| Col Operator Constant
-	{
-		printf("Pred 2\n");
-		cons_cell* first_term = create_term($1);
-		$$ = create_comp_operator($2, first_term, $3, NULL);
-	}
-	| Pred AND Col Operator Col
-	{
-		printf("Pred 3\n");
-		cons_cell* first_term = create_term($1);
-		cons_cell* second_term = create_term($3);
-		comp_cons = create_comp_operator($2, first_term, second_term, NULL);
-		$$ = create_and_operator($1, comp_cons);
-	}
-	| Pred AND Col Operator Constant
-	{
-		printf("Pred 4\n");
-		cons_cell* first_term = create_term($1);
-		cons_cell* second_term = create_term($3);
-		comp_cons = create_comp_operator($2, first_term, $3, NULL);
-		$$ = create_and_operator($1, comp_cons);
-	}
-	| Pred OR Col Operator Col
-	{
-		printf("Pred 5\n");
-		cons_cell* first_term = create_term($1);
-		cons_cell* second_term = create_term($3);
-		comp_cons = create_comp_operator($2, first_term, second_term, NULL);
-		$$ = create_or_operator($1, comp_cons);
-	}
-	| Pred OR Col Operator Constant
-	{
-		printf("Pred 6\n");
-		cons_cell* first_term = create_term($1);
-		cons_cell* second_term = create_term($3);
-		comp_cons = create_comp_operator($2, first_term, $3, NULL);
-		$$ = create_or_operator($1, comp_cons);
-	}
-	| NOT Pred
-	{
-		printf("Pred 7\n");
-		$$ = create_not_operator($1, NULL);
-	}
-	| EXIST '(' SELECT STAR Body ')'
-	{
-		printf("Pred 8\n")
-		// todo: create exist operator?
-	}
-	;
+	: Conj
+	| Pred OR Conj
+	| BasicPred
+	| Conj AND BasicPred
+
+BasicPred
+	: Term CompOperator Term
+	| EXIST '(' Body ')'
+	| NOT BasicPred
+	| '(' Pred ')'
+
+Term
+	: Constant
+	| TableList
+
+
+
 
 Constant
 	: INTEGER
@@ -268,3 +230,5 @@ Constant
 		printf("STRING is |%s|", yytext);
 		$$ = create_constant(yytext);
 	}
+	;
+