I'm old-school, object-oriented programming didn't start to get mainstream until I'd been in the industry 20 years (the roots go back to before my start, of course). And then Perl has a not completely generic approach to objects.

Today I learned, less painfully than I might have, that when I instantiate an object in one program, use Dumper to make it a string, send that to another program, and eval the string, I get an object exactly matching what Dumper saw (I know there are cases where it can't do that, but my situation is simple and that part works). But...the blessed object and the class/package it's associated with don't interlock. So, having forgotten to include that package in the second program, evaling the Dumper string gave me a blessed object (hash, in this case) with all the right members -- but didn't notice that the package was missing, and that therefore all the methods, including accessors, were missing.

Oops!

I didn't take that long to realize what was wrong, even. It's a cleavage line I don't think exists in most other object environments.

No particular point beyond this; I'm not saying this is bad and must be fixed or anything. It's an extra way to screw up (which I exploited :-) ) made possible by the flexibility of Perl's rather ad-hoc approach to objects. "Meditation" is about right; I'm just thinking about this out loud.

I suppose you could make this a slightly harder mistake, but only by making some low-level changes. If a blessed object kept track of whether it was associated with a package of that name, and the information went into the Dumper output, then when the string was evaled, if there was no package of the right name loaded, it could point that out (optional extra parameter to bless, or something?). Huh; my first thought was that it was going to be hopeless, but maybe there are holes in that idea I haven't noticed yet. I wonder if there is code out there that deliberately uses this somehow?

In reply to Class / package weak association by dd-b

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