RE: map-put! and (setf (map-elt ...) ..) on lists

[Drew Adams]

> >> map-put!:
> >>  Associate KEY with VALUE in MAP and return VALUE.
> >>  If KEY is already present in MAP, replace the associated value
> >>  with VALUE.
> 
> Not sure which version you were looking at,

The version I downloaded from Master on 2019-12-17,
the same day I wrote that.

(cl-defgeneric map-put! (map key value)
  "Associate KEY with VALUE in MAP and return VALUE.
If KEY is already present in MAP, replace the associated value
with VALUE."
  (map--dispatch map
    :list (let ((p (assoc key map)))
            (if p (setcdr p value)
              (error "No place to change the mapping for %S" key)))
    :hash-table (puthash key value map)
    :array (aset map key value)))

> but what I see is:
>       "Associate KEY with VALUE in MAP.
>     If KEY is already present in MAP, replace the associated value
>     with VALUE.
>     This operates by modifying MAP in place.
>     If it cannot do that, it signals the `map-not-inplace' error.
>     If you want to insert an element without modifying MAP, use `map-
>     insert'."

LGTM.  Thanks for making that change/addition.

> I think normal code should never call this function
> directly and should use `(setf (map-elt ...) ..)` instead anyway!
> So, even a longwinded name would be perfectly fine.

1. Maybe such a statement should be made somewhere for
users, if it's not made already - and with maybe some
description of what is meant by either "normal code"
or (more likely) the abnormal code where it might make
sense to use this.

2. +1 for a long-winded name, if Emacs wants to make
the name proclaim that the function is destructive.
Maybe something like `map-put-in-place' or
`in-place-map-put' or `map-put-set' or `map-put-modify'
(no, I don't have a great suggestion).