How to find object variable?

[Stefan Urbanek]

Hi,

In latest StepTalk update I had a problem finding whether receiver knows about a
variable with a given name. I do not care whether it is a real ivar or not. I
have used following code:

        NS_DURING
            /* test whether variable is an ivar s*/
            obj = [receiver valueForKey:varName];
            NSDebugLLog(@"STCompiler", "New name: receiver variable %@",
varName);
            [receiverVars addObject:varName];
        NS_HANDLER
            if([[localException name] isEqualToString:NSUnknownKeyException])
            {
            NSDebugLLog(@"STCompiler", "New name: extern %@", varName);
                /* receiver has no such variable */
                [externVars addObject:varName];
            }
            else
            {
                [localException raise];
            }
        NS_ENDHANDLER

Basically, what I do is to try to get a value for given key. If it exists, then
I assume that the receiver has that ivar.

Is there a better and cleaner way of doing that?

Thanks for any hints,

Stefan Urbanek

p.s.: GNUstep has NSUnknownKeyException where Cocoa has NSUndefinedKeyException,
I think that for compatibility reasons we should have the second instead.
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