FUNCTION BREAK STATEMENT

▶ FUNCTION BREAK STATEMENT

Function break statements are used when the execution of the enclosing function needs to be stopped immediately.

To make a function break statement, write:

Tyl symbolizer will replace the double percent code '%%', with '✖✖', the function break symbol:

✖✖

Consider this program:

num 6

divisor 0

num // divisor

print num

The critical division by zero line num // divisor, and all lines thereafter, will not be executed since the function break line '%%', will cause the system to stop executing the program.

Say we have a divide by program:

go:

num 6

divideby num 2

divideby num divisor: num // divisor

All divisions by non zero divisors will be fine. But to ensure code integrity, we need to handle also the zero divisor case.

We add global ok variable to the program:

ok \t

go:

num 6

divisor 2 ~

result divideby num divisor

not ok ?

print 'Division by zero!'

print 'Division result: ' + result

divideby num divisor:

ok \t

divisor 0 ? %% ok \f

num // divisor

In divideby function, the zero divisor check statement 'divisor 0 ?', will activate function break statement '%% ok \f'. As with all break statements, a statement can be activated upon breaking, so ok flag will be turned off, and function execution will be stopped. If divisor is not zero, division is done.