HP Pascal/iX Programmer's Guide (31502-90023)

11- 7
If the compiler can determine that b is a constant expression
whose value is true , then it does not generate code for the call
to assert .
i An integer expression. If the value of b is false and p is
specified, procedure p is called with i as the actual value
parameter. If b is false and p is not specified, the system
issues a run-time error message that includes the value of i .
A call to the predefined function statement_number is a useful
integer expression for i . It returns the statement number (as
shown on the compiler listing) for the statement from which it is
called (in this case, the call to assert ).
p The name of a procedure whose heading has the syntax
PROCEDURE p ( parameter_name : integer);
If the value of b is false and p is specified, the system
executes the call p(i) .
Figure 11-1 illustrates how the predefined procedure assert works.
Figure 11-1. How the Predefined Procedure Assert Works