Custom functions added do not have a label so it might be hard to remember them.
After looking at the source, it looks like the only option is to provide your own implementation of org-agenda-bulk-action.
I hope to be proven wrong though.
It's possible to hack around pretty much everything in elisp using a combination of temporarily rebinding functions and advice.
In this case, you could add some advice around org-agenda-bulk-action to redefine char-to-string in its body, which org-agenda-bulk-action calls to format the custom binding message. This local version of char-to-string checks an alist for additional messages, ("[D<+day>]" for your ?D binding).
;; give custom keys an extra message
(defvar my-custom-mappings '((?D . "<+Day>")))
;; redefine `char-to-string' in the body of `org-agenda-bulk-action'
(define-advice org-agenda-bulk-action (:around (orig-fn &rest args) "custom-msg")
(cl-letf (((symbol-function 'char-to-string)
(lambda (char)
(let ((msg (assoc char my-custom-mappings)))
(if msg (format "%c%s" (car msg) (cdr msg))
(format "%c" char))))))
(apply orig-fn args)))
Of course, this is fairly brittle with respect to changes in the source.
Related
Why does the following not work?
;;;; foo.lisp
(in-package :cl-user)
(eval-when (:compile-toplevel :load-toplevel :execute)
(require :cl-interpol))
(cl-interpol:enable-interpol-syntax)
(defun read-and-eval (s)
(eval (read-from-string s)))
(cl-interpol:disable-interpol-syntax)
then:
LISP> (load (compile-file "foo.lisp"))
=> T
LISP> (read-and-eval
"(let ((a \"foo\")) (princ #?\"${a}\"))")
=> no dispatch function defined for #\?
Because there's only a single reader, with global state. You're effectively turning your macros on and off. In this case the reader macros are enabled only for the duration that your read-and-eval function is read at compile time.
In this case you would need to set the macros up within the read-and-eval function to ensure the reader is in the proper state when you need it.
CL:READ dispatches based on the readtable bound to CL:*READTABLE* at the time the call to READ runs. Under the hood ENABLE-INTERPOL-SYNTAX is creating a new readtable, setting CL:*READTABLE* to hold it, and stashing the old value of CL:*READTABLE*. DISABLE-INTERPOL-SYNTAX is unstashing the previous readtable and setting CL:*READTABLE* to again hold it. Minimally changing your original setup, you can arrange for the behavior you wanted by the following:
(in-package :cl-user)
(eval-when (:compile-toplevel :load-toplevel :execute)
(require :cl-interpol))
(cl-interpol:enable-interpol-syntax)
(defvar *interpol-reader* *readtable*)
(cl-interpol:disable-interpol-syntax)
(defun read-and-eval (s)
(let ((*readtable* *interpol-reader*))
(eval (read-from-string s))))
The call to disable the syntax could be placed anywhere after the defvar and read-and-eval will still work, but if you want to directly input interpol syntax in the file that syntax will have to be placed between the enable and disable calls. For that latter purpose it is significant that the interpol calls expand into EVAL-WHENs, for the same reason that it is necessary for your call to REQUIRE to be within an EVAL-WHEN; that is, the effects need to have already happened when the latter forms are READ.
CL-INTERPOL's interface abstracts what is happening, so I will show you how you might manually create and change a readtable:
;; Create a fresh readtable with standard syntax
(defvar *not-readtable* (copy-readtable nil))
;; A simple reader function
(defun not-reader (stream char &optional count)
"Like ' but for (not ...) instead of (quote ...)"
(declare (ignore count char))
`(not ,(read stream t nil t)))
;; Mutate that readtable so that the dispatch character you want
;; calls the function you want
(set-macro-character #\! 'not-reader nil *not-readtable*)
;; Try it out
(let ((*readtable* *not-readtable*))
(read-from-string "(if !foo bar baz)"))
=>
(IF (NOT FOO)
BAR
BAZ)
The only thing I don't like about Emacs is the lack of namespaces, so I'm wondering if I can implement them on my own.
This is my first attempt, and it's obvious that I can't just replace every match of a name with its prefixed version, but what should I check? I can check for bindings with (let) then mark the entire subtree, but what if somebody creates a (my-let) function that uses let? Is my effort destined to fail? :(
Also, why are my defuns failing to define the function? Do I have to run something similar to intern-symbol on every new token?
Thanks!
Since this is the first google result for elisp namespaces...
There's a minimalist implementation of namespaces called fakespace which you can get on elpa, which does basic encapsulation. I'm working on something ambitious myself, which you can check out here.
To handle things like my-let or my-defun, you need to macroexpand those definitions, e.g. with macroexpand-all.
For the failure to define the functions, you need to use intern instead of make-symbol (because make-symbol always creates a new distinct fresh uninterned symbol).
Adding namespaces will take more than prefixing the identifiers with the namespace names. The interpreter has to be able to tell the namespaces. Some tinkering must go into the interpreter as well. That might need to go through a thorough discussion at gnu.emacs.sources and/or #emacs at irc.freenode.org.
This is a fixed version of the code from #vpit3833 to provide namespace support (using the hint from #Stefan). It’s too good to leave around half-fixed :)
;; Simple namespace definitions for easier elisp writing and clean
;; access from outside. Pythonesque elisp :)
;;
;; thanks to vpit3833 → http://6e5e5ae9206fa093.paste.se/
(defmacro namespace (prefix &rest sexps)
(let* ((naive-dfs-map
(lambda (fun tree)
(mapcar (lambda (n) (if (listp n) (funcall naive-dfs-map fun n)
(funcall fun n))) tree)))
(to-rewrite (loop for sexp in sexps
when (member (car sexp)
'(defvar defmacro defun))
collect (cadr sexp)))
(fixed-sexps (funcall naive-dfs-map
(lambda (n) (if (member n to-rewrite)
(intern
(format "%s-%s" prefix n)) n))
sexps)))
`(progn ,#fixed-sexps)))
;; (namespace test
;; (defun three () 3)
;; (defun four () (let ((three 4)) three))
;; (defun + (&rest args) (apply #'- args)))
;; (test-+ 1 2 3)
(provide 'namespace)
I'm using folding-mode in emacs and was trying to make a function to insert the appropriate folding marker (start or end) depending on mode. So far I have
(defun insert-folding-mode-mark ()
(interactive)
(let ((st "##{{{")
(en "##}}}")
string-to-insert)
(save-excursion
(setq string-to-insert
(let ((here (point))
sp ep)
(setq sp (search-backward st))
(goto-char here)
(setq ep (search-backward en))
(if (< sp ep) st en))))
(insert string-to-insert)))
This inserts "##{{{" at (point) unless "##{{{" precedes it, in which case it inserts "##}}}".
I'd like to replace the first (let) assignment with something that determines the start and end markers with something like
(let* ((match (assoc (intern mode-name) folding-mode-marks-alist))
(st (nth 1 match))
(en (nth 2 match)))
[is (intern) meant to be called in this way?] A truncated version of my folding-mode-marks-alist looks something like
((ess-mode "##{{{" "##}}}")
(tex-mode "%{{{" "%}}}")
(python-mode "# {{{" "# }}}")
(emacs-lisp-mode ";;{{{" ";;}}}")
(TeX-mode "%{{{" "%}}}")
(LaTeX-mode "%{{{" "%}}}"))
while the mode-name returned from various modes are {"Emacs-Lisp", "ESS[S]", "PDFLaTeX", "Python", ...}. Seems like I might want to do some partial matching with strings using (downcase), (concat x "-mode"), and so on, but was wondering if there was an idiomatic way in emacs lisp to do this sort of matching with keys of an alist, or do I just have to have a separate block of code by which I extract the keys with (mapcar 'car folding-mode-marks-alist) and convert each symbol to string (how?) to do the matching?
Thanks much!
Emacs Lisp has a destructuring-bind facility which may be helpful here. Also taking advantage of the fact that the symbol naming the current major mode is available via the variable major-mode, you can write something like this:
(destructuring-bind (st en) (cdr (assoc major-mode folding-mode-marks-alist))
; do stuff
)
Note that this won't work if (assoc major-mode folding-mode-marks-alist) returns nil, so better replace that with a call to some custom function capable of returning a sensible default.
In addition to major-mode being more appropriate than mode-name here, the function insert-folding-mode-mark as listed above would throw an error if there were no folding marker between cursor and beginning of buffer. Here is a revision without that quirk:
(require 'cl)
(defun insert-folding-mode-mark ()
(interactive)
(flet ((fn (s) (save-excursion (or (search-backward s () t) 0))))
(destructuring-bind (mode st en)
(or (assoc major-mode folding-mode-marks-alist) '(nil "" ""))
(insert (if (<= (fn st) (fn en)) st en)))))
Edit: fix problem pointed out in comment.
You may be interested to know there are comment-start and comment-end variables which should already contain the information you need based on major-mode. Something like
(search-backward (concat comment-start "{{{"))
...
(insert comment-start "{{{" comment-end)
should be sufficient. Of course, for lisp modes comment-start is ";" so you may want to do what you are doing to get ";;" but fall back on comment-start for other modes. You can also (setq comment-start ";;") though I'm not entirely sure what difference that makes for the lisp modes.
I've been using Emacs for a couple months now, and I want to get started in elisp programming. Specifically, I'd like to write my own interactive function. However, I'm more than a bit lost. (interactive ...) has tons of options and I'm not sure which one I want. Then, I don't really know the names of the functions I need. If someone could kindly help me turn my pseudocode into real code, I would be mighty appreciative! (And as always, any links to informative places would be good. Right now I've just been reading this.)
Here is pseudocode for what I'd like to do:
(defun my-func (buffer) ; I think I need the buffer as an arg?
"does some replacements"
(interactive ???) ; ?
(let (replacements (list
'("a-regexp-string" . "a-replacement-string-with-backreferences")
...)) ; more of the above
(while replacements
(let (current (car replacements)) ; get a regexp-replacement pair
(some-regexp-replace-func buffer (car current) (cdr current)) ; do the replacement
(setq replacements (cdr replacements))))))
First, from the looks of your function you would probably be doing it in the current buffer, so no, you don't need to have a 'buffer' argument. If that's a bad assumption, I can change the code. Next, in a 'let' if you are assigning to variables you need another set of parens around each pair of var/value. Finally, when looping through a list I prefer to use functional-programming-like functions (mapcar, mapc, etc.). I'll try to inline some comments here:
(defun my-func ()
"Do some replacements"
(interactive)
(let ((replacements (list '("foo" . "bar")
'("baz" . "quux"))))
(save-excursion ; So point isn't moved after this function
(mapc (lambda (x) ; Go through the list, with this 'inline' function
; being called with each element as the variable 'x'
(goto-char (point-min)) ; Start at the beginning of the buffer
(while (re-search-forward (car x) nil t) ; Search for the car of the replacement
(replace-match (cdr x)))) ; And replace it with the cdr
replacements)))) ; The list we're mapc'ing through
As for what to read, I'd suggest the Elisp manual that comes with Emacs.
...just like packages do.
I use Emacs (maybe, it can offer some kind of solution).
For example (defun the-very-very-long-but-good-name () ...) is not to useful later in code. But the name like Fn-15 or the first letters abbreviation is not useful too.
Is it possible either to have an alias like for packages or to access the documentation string while trying to recall the function's name?
In other words, is it possible for functions to mix somehow self-documenting and short names?
You want defalias. (defalias 'newname 'oldname) will preserve documentation and even show "newname is an alias for `oldname'" when its documentation is requested.
You could use setf to assign the function to the function cell of another, for example:
(defmacro alias (new-name prev-name)
`(setf (symbol-function ,new-name) (symbol-function ,prev-name)))
from 《On Lisp》？Here is the code:
(defmacro alias (new-name prev-name)
`(defmacro ,new-name (&rest args)
`(,',prev-name ,#args)))
; use: (alias df defun)
(defun group (source n)
(if (zerop n) (error "zero length"))
(labels ((rec (source acc)
(let ((rest (nthcdr n source)))
(if (consp rest)
(rec rest (cons (subseq source 0 n) acc))
(nreverse (cons source acc))))))
(if source (rec source nil) nil)))
(defmacro aliasx (&rest names)
`(alias
,#(mapcar #'(lambda (pair)
`(alias ,#pair))
(group names 2))))
; use: (aliasx df1 defun
; df2 defun
; df3 defun)
If it's all the typing which makes continual use of long names undesirable, then yes, emacs can help. Check out abbrev-mode. Also well thought-of in this context is hippie-expand.
If it's a question of readability, that's harder.
If your problem is that you can't remember a very long function name, but you remember PART of the name, that's what "apropos" is for. In my Emacs, I have "C-h a" bound to "hyper-apropos". You enter a substring of the symbol you're looking for, and it lists all the matches.
I dont know Emacs, but wouldn't (define shortname longnamefunctionblahblah) work?
You could simply have a function that just calls another function.
you can use (defmacro ...) to alias a function