The GNU Emacs Lisp Reference Manual, 12.5 Defining Global Variables:
If you use a
defconstordefvarspecial form while the variable has a local binding (made withlet, or a function argument), it sets the local binding rather than the global binding.
But when I tried it in *scratch*:
(defun f (some-symbol)
(defconst some-symbol 1412)
some-symbol)
;; ==> f
(f 0)
;; ==> 0
some-symbol
;; ==> 1412
It seems that (defconst some-symbol 1412) didn't set the local value of some-symbol (so that (f 0) evaluates to 0), instead it made the some-symbol at top level evaluate to 1412.
Do I misunderstand the definitions of local binding and global binding?
Update
Another example that seems to work fine for @dalanicolai:
Although
defconstdoes work as documented when using it withlet:(let ((some-symbol 0)) (defconst some-symbol 1412) some-symbol)returns 1412.
but behaves weirdly in my Emacs:
*** Welcome to IELM *** Type (describe-mode) for help.
ELISP> (let ((some-symbol 0))
(defconst some-symbol 1412)
some-symbol)
0 (#o0, #x0, ?\C-@)
ELISP> (let ((some-symbol 0))
(defconst some-symbol 1412)
some-symbol)
1412 (#o2604, #x584)
ELISP>
emacs-version: 28.2
system-configuration: x86_64-w64-mingw32
defconstdoes work as documented when using it withlet:(let ((some-symbol 0)) (defconst some-symbol 1412) some-symbol)returns 1412. Then againdefvardoes not work as documented when using it withlet. To me it looks like you've encountered a 'documentation bug'.fand error on evaluatingsome-symbol. Same withlet.0!defvardoc in the upstream repo says:If SYMBOL is let-bound, then this form does not affect the local let binding but the toplevel default binding instead, like ‘set-toplevel-default-binding‘. (‘defcustom’ behaves similarly in this respect.). I think it is likely that some of these behaviors might be "fluid", as bugs are found and fixed. I suspect that they will be cleaned up as time goes on, but you should probably report what you find perplexing, particularly if it contradicts the documentation.lisp-interaction-mode(the default for vanilla Emacs, but not on e.g. Spacemacs) and NOTemacs-lisp-mode. Of course, anyway thanks for the feedback...