procyberian/emacs
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

Explicitly disallow named-let in code using dynamic binding

Browse source 
There is no point in permitting named-let to be used in dynbound code;
our code transforms are simply not valid in that context, and it's not
worth the trouble to make it work (to the extent that it is at all
possible). (Bug#59576)

* lisp/emacs-lisp/subr-x.el (named-let):
Error if used with dynamic binding.
* doc/lispref/variables.texi (Local Variables): Amend manual.
This commit is contained in:
Mattias Engdegård 2023-08-21 13:50:03 +02:00
parent f01a94fc58
commit c21103bb76
2 changed files with 7 additions and 3 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

4
doc/lispref/variables.texi
View file

@ -351,8 +351,8 @@ A function call is in the tail position if it's the very last thing
done so that the value returned by the call is the value of @var{body}
itself, as is the case in the recursive call to @code{sum} above.
@strong{Warning:} @code{named-let} works as expected only when
lexical-binding is enabled. @xref{Lexical Binding}.
@code{named-let} can only be used when lexical-binding is enabled.
@xref{Lexical Binding}.
@end defspec
Here is a complete list of the other facilities that create local

6
lisp/emacs-lisp/subr-x.el
View file

@ -312,9 +312,13 @@ it makes no sense to convert it to a string using
Like `let', bind variables in BINDINGS and then evaluate BODY,
but with the twist that BODY can evaluate itself recursively by
calling NAME, where the arguments passed to NAME are used
as the new values of the bound variables in the recursive invocation."
as the new values of the bound variables in the recursive invocation.
This construct can only be used with lexical binding."
(declare (indent 2) (debug (symbolp (&rest (symbolp form)) body)))
(require 'cl-lib)
(unless lexical-binding
(error "`named-let' requires lexical binding"))
(let ((fargs (mapcar (lambda (b) (if (consp b) (car b) b)) bindings))
(aargs (mapcar (lambda (b) (if (consp b) (cadr b))) bindings)))
;; According to the Scheme semantics of named let, `name' is not in scope