Function par_case

src/gpre/sqe.cpp:1881–1955

____________________________________________________________ Parse a CASE clause There are two types of CASE clauses. 1) CASE WHEN (cond1) THEN value1 ... ELSE else_value END which is returned as nod_case In this case nod_arg[0] = cond1, nod_arg[1] = value1, ... nod_arg[n] = else_value 2) CASE value0 WHEN test_value1 THEN match_value1 ... ELSE else_value END which is returned as nod_case1 In thi

//			   nod_arg[n] = else_value
//
static gpre_nod* par_case(gpre_req* request)
{
	gpre_lls* stack = NULL;
	int count = 0;
	nod_t nod_type;

	if (MSC_match(KW_WHEN))
	{
		// Case 1 - CASE WHEN cond1 THEN value1 ...
		nod_type = nod_case;
		count++;
		MSC_push(SQE_boolean(request, NULL), &stack);

		while (MSC_match(KW_THEN))
		{
			count++;
			MSC_push(SQE_value_or_null(request, false, NULL, NULL), &stack);
			if (MSC_match(KW_WHEN))
			{
				count++;
				MSC_push(SQE_boolean(request, NULL), &stack);
			}
		}

		// If we have an odd number of nodes then we are missing a THEN
		if ((count % 2) == 1)
		{
			CPR_s_error("THEN");
		}
	}
	else
	{
		// Case 2 - CASE value0 WHEN test_value1 THEN match_value1 ...
		nod_type = nod_case1;
		count++;
		MSC_push(SQE_value_or_null(request, false, NULL, NULL), &stack);

		while (MSC_match(KW_WHEN))
		{
			count++;
			MSC_push(SQE_value_or_null(request, false, NULL, NULL), &stack);
			if (MSC_match(KW_THEN))
			{
				count++;
				MSC_push(SQE_value_or_null(request, false, NULL, NULL), &stack);
			}
			else
			{
				CPR_s_error("THEN");
			}
		}
	}

	// ELSE else_value END
	if (MSC_match(KW_ELSE))
	{
		count++;
		MSC_push(SQE_value_or_null(request, false, NULL, NULL), &stack);