Re: Using funcall on inline functions

[Stefan Monnier <monnier@iro.umontreal.ca>]

> (define-inline ebdb-add-to-list (list-var element)
>   (inline-quote (when, element
>                   (cl-pushnew, element, list-var :test #'equal))))

This can't work: your argument is named "list-var" but the way you use
it in the body indicates that it's supposed to be a *list* not a *list
variable*.

It may happen to work in some cases when the function gets inlined, but
if so, it's actually showing a misfeature of the `define-inline`
implementation (result of some optimizations).

You can't have it both way: if `ebdb-add-to-list` is a function, then
`list-var` is a local variable and this argument uses the usual
pass-by-value semantics (and hence `cl-pushnew` will only affect that
local variable).  If you want `list-var` to be the name of the *place*
passed by the caller then it has to be a macro.

There is a workaround, then, which is to use a reference:

    (cl-defstruct ebdb-record-cache
      (alt-names nil :type list))
    
    (defclass ebdb-record ()
      ((cache :type ebdb-record-cache))) 
    
    (define-inline ebdb-record-alt-names (record)
      (inline-quote (ebdb-record-cache-alt-names
                     (slot-value,record 'cache))))
    
    (define-inline ebdb-add-to-list (list-ref element)
      (inline-quote
        (when ,element
          (cl-pushnew ,element (gv-deref ,list-ref) :test #'equal))))
    
    (let ((listfunc #'ebdb-add-to-list)
          (name-string "Bob's new name"))
      (funcall listfunc
               (gv-ref (ebdb-record-alt-names <some-record>))
               name-string))

[ BTW, your `ebdb-add-to-list` has a bug in that it will evaluate its
  second argument before its first.  ]


        Stefan