Re: [nongnu] elpa/racket-mode 363246ac70 1/2: Fix cl-loop byte-compiler warnings

[Greg Hendershott]

Genuine apologies for not really knowing the mechanics of Emacs Lisp
macro expansion. Or the specific implementation of cl-loop... or even
really much of its usage beyond a few examples I've tried in Emacs Lisp.

I guess my dumb question is this:

When I pp-macroexpand one example from my code:

    (cl-loop for i being the intervals from beg to end
             do
             (racket--region-set-face (car i) (cdr i)
                                      (funcall func
                                               (or (get-text-property (car i) 
'face)
                                                   'default))
                                      'force))

I get:

    (cl-block nil
      (cl-block --cl-finish--
        (cl--map-intervals
         (lambda
           (--cl-var1-- --cl-var2--)
           (setq i
                 (cons --cl-var1-- --cl-var2--))
           (racket--region-set-face
            (car i)
            (cdr i)
            (funcall func
                     (or
                      (get-text-property
                       (car i)
                       'face)
                      'default))
            'force))
         nil nil beg end))
      nil)

If instead of `setq` cl-loop expanded to use `let`

         (lambda
           (--cl-var1-- --cl-var2--)
           (let ((i (cons --cl-var1-- --cl-var2--))
             (racket--region-set-face
              (car i)
              (cdr i)
              (funcall func
                       (or
                        (get-text-property
                         (car i)
                         'face)
                        'default))
              'force))))

would that avoid the byte-compiler warning? If not, can it add an
`ignore`?

I guess my general question is: If I can hand-write code to avoid the
warning, and macros can write any code that I can write by hand, why
can't cl-loop do so for me?