IF statement

The XCSB if statement is a conditional construct designed to conditionally execute a sequence of statements. The general format of the if statement is:

if cond_expr then
	true_statement_list
else
	false_statement_list
endif

however the false_statement_list is optional and if omited the else can also be omited providing the alternate format:

if cond_expr then
	true_statement_list
endif

where:

cond_expr is the expression that is executed to determin which of the true_statement_list or the false_statement_list should be executed. If cond_expr produces a non-zero result the true_statement_list is executed, if cond_expr produces a zero result and a false_statement_list is present then the false_statement_list is executed

When checking for multiple conditions using a chain of if statements the code can start looking untidy very quickly. Consider

if cond_1 then
	statement_list_1
else

	if cond_2 then
		statement_list_2
	else

		if cond_3 then
			statement_list_3
		else
			false_statement_list
		endif

	endif

endif

XCSB allows a special form of the chained if statement which looks like this:

if cond_1 then
	statement_list_1

else if cond_2 then
	statement_list_2

else if cond_3 then
	statement_list_3

else
	false_statement_list
endif

This is the only time another statement is allowed on the same line as the else statement