Re: Generic functions: Specializers like `or' or `memq'?

[Stefan Monnier]

Emanuel Berg via Users list for the GNU Emacs text editor [2021-11-05 22:36:25] 
wrote:
> Stefan Monnier via Users list for the GNU Emacs text editor wrote:
>>> My earliest confusion began when I decided that if I could
>>> find the part of the code that runs the `eql' specializer
>>> (or do we call it the `eql' generalizer?) and then worked
>>> back from there, I would be able to make sense of
>>> everything. But I couldn't even find the bit of code that
>>> looks like (eql <val> <tag>)! And still can't.
>>
>> Nah, that would be too easy. Instead it happens implicitly
>> via a lookup in a hash-table.
>>
>> I suspect that the code for cl-defstruct specializer might
>> be easier to understand in this respect.
>
> What's the typical use case for this?

Not sure what "this" refers to.  If you're talking about the use case
for adding new specializers/generalizers, it's quite rare.
It's mostly a detail of `cl-generic.el` used internally.


        Stefan