Why isn't this function working?
reddit / emacs

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LowCom · 2022-05-12 06:04

(defun hidex()
      (menu-bar-mode 0)
      (tool-bar-mode 0)
      (scroll-bar-mode 0)
      )

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s-kostyaev · 2022-05-12 06:18

Try -1 instead of 0

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fraile_cucarro · 2022-05-12 06:59

Use nil

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hkjels · 2022-05-12 07:51

Use progn

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whudwl · 2022-05-12 08:16

`not working` meaning?

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7890yuiop · 2022-05-12 08:19

It works fine (I just tested it), so you need to provide more
information.

Ignore everyone who doesn't understand minor mode arguments; yours are
good/correct.

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LowCom · 2022-05-12 08:51

Oh Thanks, here is what I did.
I wrote this in lisp-interactive-mode buffer, then did eval-buffer on
the file but the menu changes didn't happen.
That's what I meant by not working .

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LowCom · 2022-05-12 08:52

I wrote this in lisp-interactive-mode buffer, then did eval-buffer on
the file but the menu changes didn't happen.
That's what I meant by not working .

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whudwl · 2022-05-12 08:54

you have defined a function. now you need to call the function by
writing `(hidex)`, place your cursor at the end of that, then `C-x
C-e`

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LowCom · 2022-05-12 08:59

It works now , thank you. Dumb me. I was calling the funciton with
hidex() as in python.   I knew the lisp function syntax but  python
became a habit  I  guess.

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SlowValue · 2022-05-12 10:32

This would just wrap that `(prog1 ...)`, which is generated by the
macro `defun`, with an additional `progn`.

*Edit*: sorry above statement is wrong. Seems like I was confused by
Common Lisps Hyperspec, which states "The body of the function defined
by defun consists of forms; they are executed as an implicit progn
when the function is called.

This is unecessary.
*Edit*: nevertheless an additional `progn` is unnecessary.

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hkjels · 2022-05-12 11:29

Wow. I’ve done a considerable amount of elisp, but did not know that.
I more often than not have a let binding at the start of my functions
though and I know that progn is not necessary then

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usaoc · 2022-05-12 12:15

[`defun` usually expands to a `defalias` with a `lambda`, unless there
are declarations, in which case the `prog1` is around the `defalias`
and declarations, not the body.](https://github.com/emacs-
mirror/emacs/blob/aeefa3a732c9dd815e23ed10c4582082acb0e29b/lisp/emacs-
lisp/byte-run.el#L351)

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SlowValue · 2022-05-12 13:16

Thanks for correcting me.

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7890yuiop · 2022-05-12 20:06

It did work: it defined a function named `hidex`.  That's what
evaluating a `defun` form does.

If you want to then *call* your function, you would use `(hidex)`.

If you wanted to evaluate the code immediately, then you didn't want a
function in the first place and hence didn't need to wrap the code in
`(defun hidex () ...)` at all.

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oantolin · 2022-05-13 17:39

> Ignore everyone who doesn't understand minor mode arguments; yours
are good/correct.

Isn't using 0 undocumented? Here's what the docstring of a typical
minor mode says:

> If called from Lisp, toggle the mode if ARG is ‘toggle’.  Enable the
mode if ARG is nil, omitted, or is a positive number. Disable the mode
if ARG is a negative number.

It says what happens for positive numbers and what happens for
negative numbers, but it doesn't say what happens for 0.