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PuercoPop/CLOS in CLOS.md

Created August 26, 2015 14:16
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CLOS in CLOS.md

Ok so a while back a ran into a problem when extending the slot options in CLOS. I went digging in SBCL and saw it uses a case based approach to process the slot arguments/options. The AMOP in page 95 shows a way to use the CLOS famework to 'teach' CLOS how to process custom options (for slots and classes) inserting a generic function to hook into called 'canonicalized-{defclass,slot}-option'. However due to bootstraping issues IIUC (which I probably don't) defgeneric isn't avaiable at the time that code is evaluated so that extension can't be included willy nilly in SBCL itself.** So it occured to me that maybe a CLOS implemented on top the implementations CLOS could provide a path of least resistance to continue improving the CLOS framework*.

* I use framework not in the software sense but in the general sense.

** A possiblity to extend SBCL for this case adding a "lookup in a hash-table case for a default case first" could be done but I would't recommend it.

@fare
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fare commented Aug 26, 2015

Or maybe, start by separating mechanisms and policy, and expose the parts necessary for JITting the code, while offering a usable protocol.

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