Re: Suggested additional example to Emacs Lisp Manual: Variables: Let

[ben rudgers]

Thanks John,

I don't disagree about the utility of cl-flet or cl-labels.

Because 'cl is documented in an independent document it is unclear to me how that example would fit into the current editorial structure of the *GNU Emacs Lisp Reference Manual*.

Obviously if 'cl-flet and 'cl-labels were merged into GNU Emacs Lisp, the example would work to illustrate a method for writing a locally defined functions. With the added benefit of avoiding the more cumbersome 'funcall structure.

Ben

 

On Sun, Jan 29, 2017 at 1:20 PM, John Wiegley <address@hidden> wrote:

>>>>> "br" == ben rudgers <address@hidden> writes:

br> The manual does not provide an example showing a locally scoped function.
br> Though the behavior can potentially be inferred from the documentation of
br> functions, an example showing the relationship between =let= and =funcall=
br> might be of practical help for someone who has not made a deep dive into
br> the manual.

I think it would be better to encourage the use of `cl-flet' or `cl-labels',
as though macros are specifically intended for binding local function
definitions, and will automatically handle whether the function should be a
`lambda' or a `closure', depending on the setting of `lexical-binding'.

Your approach may have merit in terms of pedagogy, but I'd prefer to nudge
users toward more idiomatic usage from the beginning.

@example
(require 'cl-macs)
(defun foo (x)
  (cl-flet ((bar (y) (+ x y)))
    (bar 3)))

(foo 4)
    address@hidden 7
@end example

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