Added LEFT() expression function.

Operand.cpp

@@ -11,16 +11,12 @@ namespace jet {
       
       in.skipWhitespace();
 
-//      std::cout << "op: [" << in.unparsed() << "]" << std::endl;
-
       if(in.ifNext("(")) {
-//	 std::cout << "(" << in.unparsed() << std::endl;
 	 Operand op(in);
 	 string = op.string;
 	 doubleValue = op.doubleValue;
 	 if(!in.ifNext(")")) 
 	   throw coreutils::Exception("expected ) in expression.");	      
-//	 std::cout << ")" << in.unparsed() << std::endl;	 
       } 
       
       if(in.ifNext("SUBSTRING")) {
@@ -42,7 +38,17 @@ namespace jet {
 	 else
 	   throw coreutils::Exception("Expecting ) at end of substring expression.");
       } else if(in.ifNext("LEFT")) {
-	 
+	 if(!in.ifNext("("))
+	   throw coreutils::Exception("Expecting ( for LEFT parameters.");
+	 Operand parm1(in);
+	 if(!in.ifNext(","))
+	   throw coreutils::Exception("Expecting , in LEFT expression.");
+	 Operand parm2(in);
+	 if(in.ifNext(")")) {
+	    string = parm1.string.substring(0, parm2.string.asInteger());
+	 }
+	 else
+	   throw coreutils::Exception("Expecting ) at end of LEFT expression.");	 
       } else if(in.ifNext("RIGHT")) {
 	 
       } else if(in.ifNext("TRIM")) {