From: netawater <netstandin-003@yahoo.com.cn>
To: help-gnu-emacs@gnu.org
Subject: Re: How to use elisp's closure
Date: Tue, 17 Jun 2008 21:06:48 +0800 [thread overview]
Message-ID: <8wx4gqhj.fsf@netawater.emacs> (raw)
In-Reply-To: mailman.13402.1213631610.18990.help-gnu-emacs@gnu.org
David Hansen <david.hansen@gmx.net> writes:
> On Mon, 16 Jun 2008 22:15:21 +0800 netawater wrote:
>
>> In most usual modes, TAB key is bound to an indent function and
>> M-TAB key is bound to a complete symbol function.
>> I want to write a function if cursor is at the end of word then
>> try to complete symbol, else indent. It is my function.
>>
>> (defun my-indent-or-complete (M-TAB-func TAB-func)
>> ;; "If cursor is at the end of word then current mode;s M-TAB
>> function, else TAB"
>> (lambda ()
>> (interactive)
>> (if (looking-at "\\>")
>> (apply M-TAB-func '())
>> (apply TAB-func '())
>> ))
>> )
>>
>> Then I try to bound it to \t key:
>>
>> (add-hook
>> 'find-file-hook
>> '(lambda ()
>> (let ((M-TAB-func (key-binding "\M-\t"))
>> (TAB-func (key-binding "\t"))
>> )
>> (local-set-key
>> "\t"
>> (my-indent-or-complete M-TAB-func TAB-func)))
>> )
>> )
>>
>> However it does not work, it says Symbol's value as variable
>> is void: TAB-func. I think it is because my function is not
>> a closure, but how can I resolve it?
>>
>
> Elisp is a pretty old lisp dialect... There are no closures. The
> `lexical-let' macro from the `cl' package emulates them. But in your
> case just make `M-TAB-fun' and `TAB-fun' buffer local:
>
> (defvar foo-var default-val)
> (make-variable-buffer-local 'foo-var)
>
> or
>
> (defvar foo-var default-val)
>
> (add-hook 'my-mode-hook #'(lambda ()
> (set (make-local-variable 'foo-var) val)
> ;; ...
> ))
>
> David
Thanks and besides variable is buffer local but local-set-key will bound
key for mode, so I modify my code like this:
(add-hook
'find-file-hook
'(lambda ()
(if (eq (key-binding "\t") 'my-indent-or-complete)
(local-unset-key "\t")
)
(set (make-local-variable 'M-TAB-func) (key-binding "\M-\t"))
(set (make-local-variable 'TAB-func) (key-binding "\t"))
(local-set-key "\t" 'my-indent-or-complete)
)
)
It maybe not a perfect solution, but it works, :)
prev parent reply other threads:[~2008-06-17 13:06 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-06-16 14:15 How to use elisp's closure netawater
2008-06-16 15:42 ` David Hansen
2008-06-16 15:49 ` beaubert
[not found] ` <mailman.13401.1213631425.18990.help-gnu-emacs@gnu.org>
2008-06-17 13:02 ` netawater
[not found] ` <mailman.13402.1213631610.18990.help-gnu-emacs@gnu.org>
2008-06-17 13:06 ` netawater [this message]
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