Function EXP_rse

src/gpre/exp.cpp:708–851

//

gpre_rse* EXP_rse(gpre_req* request, gpre_sym* initial_symbol)
{
	// parse FIRST n clause, if present

	gpre_nod* first = NULL;
	if (MSC_match(KW_FIRST))
	{
		if (!global_count_field)
			global_count_field = MET_make_field("jrd_count", dtype_long, 4, false);
		first = par_value(request, global_count_field);
	}

	// parse first context clause

	if (initial_symbol && gpreGlob.sw_language == lang_ada && !check_relation())
		return NULL;

	gpre_ctx* context = EXP_context(request, initial_symbol);
	SSHORT count = 1;

	// parse subsequent context clauses if this is a join
	gpre_nod* boolean = NULL;
	while (MSC_match(KW_CROSS))
	{
		context = EXP_context(request, 0);
		count++;
		if (MSC_match(KW_OVER))
			boolean = make_and(boolean, par_over(context));
	}

	// bug_3380 - could have an "over" clause without a "cross" clause
	if (MSC_match(KW_OVER))
		boolean = make_and(boolean, par_over(context));

	// build rse node

	gpre_rse* rec_expr = (gpre_rse*) MSC_alloc(RSE_LEN(count));
	rec_expr->rse_count = count;
	rec_expr->rse_first = first;
	rec_expr->rse_boolean = boolean;

	while (count)
	{
		rec_expr->rse_context[--count] = context;
		HSH_insert(context->ctx_symbol);
		context = context->ctx_next;
	}

	// parse boolean, if any.  If there is an error, ignore the
	// boolean, but keep the rse

	if (MSC_match(KW_WITH))
		boolean = make_and(boolean, par_boolean(request));

	rec_expr->rse_boolean = boolean;

	// Parse SORT clause, if any.