On 2025-05-24 12:52, David Ponce wrote:
> Hello Stefan,
> 
> Please find below the proposal for a new approach to speed up dispatch
> of methods with derived type specializers.

Hello Stefan,

Following our last exchange in French, to feed our discussion more
concretely, please find attached a new patch that explore further the
idea of removing the global variable `cl--derived-type-list', and make
`cl-types-of' a private function named `cl--derived-type-specializers'
with a mandatory argument to receive the list of dispatch types to
check.

The patch also improve a little the `cl-deftype' macro to allow
dispatching of atomic derived type with both optional
arguments and parents, like in this example:

(cl-deftype my-integer ()
   'integer)

;; Currently the below declaration is not valid because ARGLIST and
;; PARENTS are both non-nil.
(cl-deftype unsigned-byte (&optional bits)
   "Unsigned integer."
   (declare (parents my-integer))
   `(integer 0 ,(if (memq bits '(nil *)) bits (1- (ash 1 bits)))))

(cl-defmethod test-byte ((this my-integer))
   (format "%S is an integer" this))

(cl-defmethod test-byte ((this unsigned-byte))
   (format "%S is an unsigned byte - %s" this
           (cl-call-next-method)))

David