How to prevent Oracle to use short circuit in PL/SQL - plsql

Question

The following PL/SQL code shows the function ensure(...) and how I will use it in Oracle 11g.
declare
valid boolean;
function ensure(b boolean, failure_message varchar) return boolean is begin
if not b then
dbms_output.put_line(failure_message);
return false;
else
return true;
end if;
end ensure;
begin
valid := true;
valid := valid
and ensure(1=1, 'condition 1 failed')
and ensure(1=2, 'condition 2 failed')
and ensure(2=3, 'condition 3 failed');
if not valid then
dbms_output.put_line('some conditions failed, terminate the program');
return;
end if;
dbms_output.put_line('do the work');
end;
/
I want to use ensure(...) to pre-validate a set of conditions, the program is allowed to do the work only if all conditions pass.
I want the program to evaluate every ensure(...) even if the preceding ensure(...) return false, so that the failure_message will be printed for every conditions that fails.
The problem is Oracle uses short-circuit evaluation and ignore the rest conditions that come after the one that return false. For example, the above program prints the following message.
condition 2 failed
some conditions failed, terminate the program
How to tell Oracle to not use short-circuit evaluation so that the above program print the following message.
condition 2 failed
condition 3 failed
some conditions failed, terminate the program

Answer 1

Try:
declare
valid boolean;
con1 boolean;
con2 boolean;
con3 boolean;
function ensure(b boolean, failure_message varchar) return boolean is begin
if not b then
dbms_output.put_line(failure_message);
return false;
else
return true;
end if;
end ensure;
begin
valid := true;
con1 := ensure(1=1, 'condition 1 failed') ;
con2 := ensure(1=2, 'condition 2 failed') ;
con3 := ensure(2=3, 'condition 3 failed');
valid := con1 AND con2 AND con3;
if not valid then
dbms_output.put_line('some conditions failed, terminate the program');
return;
end if;
dbms_output.put_line('do the work');
end;
/

Answer 2

I usually validate preconditions with assertions. I don't know if this is suitable in the OP's case, but I think it's a worth of mentioning as a viable solution alternative.
Example:
declare
procedure assert(p_cond in boolean, p_details in varchar2 default null) is
begin
if not p_cond then
raise_application_error(-20100, p_details);
end if;
end;
begin
assert(1 = 1, 'first');
assert(1 = 2, 'second');
assert(1 = 1, 'third');
-- all preconditions are valid, processing is "safe"
end;
/
Obviously in real code/logic one must considered how the exceptions should be handled. Also state variables might be used/required.