Unsure of error in passing an anonymous function to another function

Unsure of error in passing an anonymous function to another function

[Grant Rettke]

Good evening,

Emacs-Lisp question.

Emacs: 24.4.1.

Lexical binding: nil

Trying to refactor a function. Broke it down by my intention:

• Save excursion
• Go to start of buffer
• Do something (In this case just insert some text to see that is is working)

Expected result

• To see "XXX" at the start of the buffer

Actual result

• save-excursion: Symbol's function definition is void: fn
• the function `fn' is not known to be defined.

To address this I started by reading more on Emacs-Lisp and scoping and
function definitions.

What am I doing wrong?

┌────
│ (defun doer (fn)
│   (interactive)
│   (save-excursion
│     (goto-char (point-min))
│     (fn)))
│
│ (defun useit ()
│   (interactive)
│   (doer
│    (lambda ()
│      (insert "XXX"))))
│
│ (useit)
└────

Grant Rettke
--
gcr@wisdomandwonder.com | http://www.wisdomandwonder.com/
“Wisdom begins in wonder.” --Socrates
“All creativity is an extended form of a joke.” --Kay
((λ (x) (x x)) (λ (x) (x x)))
“Life has become immeasurably better since I have been forced to stop
taking it seriously.” --Thompson

Re: Unsure of error in passing an anonymous function to another function

[Ian Zimmerman]

On 2015-08-15 21:44 -0500, Grant Rettke wrote:

> What am I doing wrong?

Elisp is not Scheme (sadly).  Function bindings are separate from
variable bindings.  To use the function binding you need funcall (which
see in the docs).

> (defun doer (fn)
>   (interactive)
>   (save-excursion
>     (goto-char (point-min))
>     (fn)))

(defun doer (fn)
  (interactive)
  (save-excursion
  (goto-char (point-min))
  (funcall fn)))

Btw, please don't use that "pretty" quoting, it just gets in the way.

-- 
Please *no* private copies of mailing list or newsgroup messages.
Rule 420: All persons more than eight miles high to leave the court.

Re: Unsure of error in passing an anonymous function to another function

[Rusi]

On Sunday, August 16, 2015 at 8:27:04 AM UTC+5:30, Ian Zimmerman wrote:
> On 2015-08-15 21:44 -0500, Grant Rettke wrote:
> 
> > What am I doing wrong?
> 
> Elisp is not Scheme (sadly).  Function bindings are separate from
> variable bindings.  To use the function binding you need funcall (which
> see in the docs).

Funcall is the solution
The problem is elisp is a lisp-2; See
http://www.nhplace.com/kent/Papers/Technical-Issues.html

Re: Unsure of error in passing an anonymous function to another function

[Joost Kremers]

Ian Zimmerman wrote:
> Elisp is not Scheme (sadly).

Thank $DEITY it isn't!

;-)


-- 
Joost Kremers                                   joostkremers@fastmail.fm
Selbst in die Unterwelt dringt durch Spalten Licht
EN:SiS(9)

Re: Unsure of error in passing an anonymous function to another function

[Grant Rettke]

Thank for all of your replies.
Grant Rettke
--
gcr@wisdomandwonder.com | http://www.wisdomandwonder.com/
“Wisdom begins in wonder.” --Socrates
“All creativity is an extended form of a joke.” --Kay
((λ (x) (x x)) (λ (x) (x x)))
“Life has become immeasurably better since I have been forced to stop
taking it seriously.” --Thompson


On Mon, Aug 17, 2015 at 2:53 AM, Joost Kremers
<joost.m.kremers@gmail.com> wrote:
> Ian Zimmerman wrote:
>> Elisp is not Scheme (sadly).
>
> Thank $DEITY it isn't!
>
> ;-)
>
>
> --
> Joost Kremers                                   joostkremers@fastmail.fm
> Selbst in die Unterwelt dringt durch Spalten Licht
> EN:SiS(9)