exception handling in skill/ocean

 Hi there,

Have a look at

errset(skill_expr [bool])

It tries to execute skill_expr,

if it is ok the result is return as list

if skill_expr rise an error then returns nil, if bool == t the error message is also printed.

E.g.

errset(x = list(1 2 3))
((1 2 3))
errset(x = listx(1 2 3))
nil
errset(x = listx(1 2 3) t)
*Error* eval: undefined function - listx
nil

BR,

Marcel

 The other approach I would recommend is actually checking the return values of various functions in your code. For example, v("/out" ?result 'tran) will return nil if that signal is not there. Similarly other functions may return nil (such as riseTime) if there is no rising edge - so conditional checks in your code will allow you to detect when things are not correct.

errset() is the alternative as Marcel suggested, but often more defensive programming will allow you to cope with differences in the data more eloquently than just trapping errors.

Regards,

Andrew.

 Hi *,

of course Andrew is right.

Better to use if/else to "validate" data.

I use errset when generate and execute skill code on the fly, sometimes I generate syntax errors or call missing/unexisting functions and that's the only way to catch them.

Best Regards,

Marcel

The logic is unassailable. But what can we do to make the programming easier. At our location we've had people take full-fledged ocean-scripting classes and still, no one uses it. It's extremely unfriendly. How can we go from "linux" to "ipad"?

Putting in all this error-checking will only make the code even more intimidating..

BTW, did you mean "elegantly" or "eloquently"? :)

If you want iPad, use ADE XL - which captures much of this in a UI. Programming languages are by nature flexble - and with flexibility comes (unfortunately) the need to cope with unexpected situations - it's very hard for a general programming language to do the right thing if it has no idea what the right thing should be given that your code could do anything...

And yes I did mean eloquently (well written (yes, strictly it's well spoken, but I thought I'd be free to adapt my own language!)), but "elegantly" fits too.

It really shouldn't be intimidating. Usually the conditions don't have to be complicated. I normally advise people to use things like:

unless(member('tran results())
  ...
)

to check if the transient results are present - little idioms like this are easy enough to remember, even for non-programmers (and most engineers should have at least some programming knowledge these days).

Glad they take the OCEAN class (I wrote it!). Surprised it's not used that much though - I tend to find many users who do because of the flexibility it gives them.

Regards,

Andrew.

Andrew,

If there are some errors when execute the OCEAN scripts,  how can I exit the OCEAN (or OCEAN environment)? I found the ocean is always hangng if there are errors. I am looking for some error handling solutions like other languages in OCEAN.

Thanks,

Jerry 

Hi Jerry,

You can use "errset" to wrap or programmatically trap errors, as noted briefly in Solution 11508500 or Solution 11030618.

Hopefully this answers your question?

Regards,

Lawrence.

Jerry,

The various strategies (using conditional statements to detect presence of results, using errset) have been covered earlier in this thread. I wouldn't expect that errors would cause anything to hang though - so presumably the problem you're seeing is down to something else.

Maybe contacting customer support with the details of your problem would be wise?

Regards,

Andrew.

Lawrence and Andrew,

errset does resolve my issue.

Thank you very much for your help!

Regards,

Jerry