newlispfanclub.alh.net

Posted: **Wed Sep 16, 2009 8:44 pm**

Hey all....

Fooling around, getting comfortable with newLISP! Currently learning to load modules; trap load errors; checking for existence of files, etc. I cobbled together the following:

Code: Select all

(define (load_mod x)
	(if (file? (append (env "NEWLISPDIR") "/modules/" x)) (print "Loading module: " x)
		 (throw-error  "module does not exist")
	)
)

So, obviously, I'm first checking whether or not the required file "x", exists. If it does, it will get loaded (I have only a debug msg. at the moment).

Is there a way to absolutely tell that the file did get loaded?

Should "load_mod" be called from within a "catch", e.g.

(catch (load_mod "cgi.lsp")) ?

Posted: **Thu Sep 17, 2009 4:58 pm**

You might be able to get away with something as simple as this:

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(define (load-module x)
    (set 'module (append (env "NEWLISPDIR") "/modules/" x))
    (catch (load module) 'error))

(load-module "cgi.lsp")

which returns true or nil. If nil, you could do something with the error message stored in 'error.

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(unless (load-module "cg.lsp")
   (println "sorry dude: " error (exit)))

Posted: **Fri Sep 18, 2009 3:26 am**

Cool!

I have to admit that this "catch-throw" thing is throwing me for a loop. I'll just have to study some more code.

Thanks for the input.

newlispfanclub.alh.net

Trapping file ops errors

Trapping file ops errors