Revert "Support unary '+' operators for strings (#3013)" (#3282)

This reverts commit 8ad86ff.
[PR 3013](#3013) incorrectly ended up in BABEL_4_4_STABLE.

Signed-off-by: Rob Verschoor <[email protected]>

contrib/babelfishpg_tsql/src/tsqlIface.cpp

@@ -2483,11 +2483,11 @@ class tsqlBuilder : public tsqlCommonMutator
 	{
 		// Check for comparison operators directly followed by an '@@' variable, like =@@
 		handleAtAtVarInPredicate(ctx);
-	}	
+	}		
 	void exitUnary_op_expr(TSqlParser::Unary_op_exprContext *ctx) override
 	{
 		handleBitNotOperator(ctx);
-	}		
+	}
 	void exitPlus_minus_bit_expr(TSqlParser::Plus_minus_bit_exprContext *ctx) override
 	{
 		handleBitOperators(ctx);
@@ -3201,7 +3201,10 @@ class tsqlMutator : public TSqlParserBaseListener
 		// Check for comparison operators directly followed by an '@@' variable, like =@@
 		handleAtAtVarInPredicate(ctx);
 	}	
-
+	void exitUnary_op_expr(TSqlParser::Unary_op_exprContext *ctx) override
+	{
+		handleBitNotOperator(ctx);
+	}
 	void exitPlus_minus_bit_expr(TSqlParser::Plus_minus_bit_exprContext *ctx) override
 	{
 		handleBitOperators(ctx);
@@ -3210,54 +3213,6 @@ class tsqlMutator : public TSqlParserBaseListener
 	{
 		handleModuloOperator(ctx);
 	}
-
-	void enterUnary_op_expr(TSqlParser::Unary_op_exprContext *ctx) override
-	{
-		/* 
-		 * The T-SQL grammar allows an arbitrary number of unary '+' operators to precede an expression, 
-		 * but PG only supports that for numeric expressions. For string expressions, such a '+' will raise an error in PG.
-		 * In SQL this shows as redundant operators, for example for concatenation: SELECT 'a' ++ 'b'. Expressions
-		 * such as +++(+++@v)) are also valid syntax according to the T-SQL grammar even though they look unusual.
-		 * Here we remove such unary '+' operators, which are redundant anyway. 
-		 * However we do not touch numeric constants (e.g. +123) since the '+', although still redundant, may
-		 * have been included for code clarity (e.g. +123 as opposed to -123).
-		 */
-		std::string op = getFullText(ctx->op);	
-		if (op.front() == '+') {	
-			auto rhsctx = ctx->expression();
-			while (true) {						
-				std::string rhs = getFullText(rhsctx);
-				if (
-					(rhs.front() == '\'') ||    // single-quoted strings
-					(rhs.front() == '"')  ||    // both double-quoted strings and double-quoted identifiers
-					(rhs.front() == '@')  ||    // variables
-					(rhs.front() == '(')  ||    // bracketed expressions			
-					(rhs.front() == '[')  ||    // bracket-delimited identifiers
-					(rhs.front() == '_')  ||    // identifiers starting with an underscore
-					std::isalpha(rhs.front())   // identifiers as well as the N'...' string notation
-				   ) {
-					stream.setText(ctx->op->getStartIndex(), " ");	
-					break;
-				}
-				if (rhs.front() == '+')  {
-					if (dynamic_cast<TSqlParser::Unary_op_exprContext *>(rhsctx)) {
-						TSqlParser::Unary_op_exprContext *uctx = static_cast<TSqlParser::Unary_op_exprContext *>(rhsctx);
-						op = getFullText(uctx->op);	
-						if (op.front() == '+') {
-							rhsctx = uctx->expression();	
-							continue;
-						}
-					}
-				}	
-				break; 
-			}
-		}
-		return;
-	}	
-	void exitUnary_op_expr(TSqlParser::Unary_op_exprContext *ctx) override
-	{
-		handleBitNotOperator(ctx);
-	}
 
 };