Questions tagged [arguments]
"arguments" refer to those inputs to a function or program which are configurable by the caller, potentially differing on each call. Every argument is an input, but not every input is an argument -- for instance, a stream of data from a mouse could be an input and not an argument.
31
questions
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1answer
12 views
Validating Arguments to a Function
I would like to validate the argument to a function before its action is executed. The main concern is the passing of a void variable. How can I trap this?
(defun is-it-bound(item)
(if (boundp 'item)...
0
votes
1answer
33 views
Passing variable to a function consisting of multiple components
Consider the following example:
(defun glue (str1 str2)
(format "%s%s" str1 str2))
(setq str1 "Hello, ")
(setq str2 "World!")
(insert (glue str1 str2))
This inserts ...
0
votes
1answer
18 views
New `wrong-number-of-arguments` error from `desktop-change-dir` and other commands
(This has started happening with other commands too, but I don't remember which.)
Previously when I ran M-x desktop-change-dir I would be prompted to enter a folder, whereupon Emacs would load the ....
0
votes
1answer
39 views
How to use header-args variables to fill cell values of a table
I have an org-mode file as such:
* Header level 1
:header-args: :var filename="somefile.csv"
** Header level 2
:header-args: :var foo="bar"
#+begin_src emacs-lisp
foo
#+end_src
#+...
1
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3answers
164 views
how to find number of arguments expected by an elisp function in emacs
I have some code that I use in my .emacs file that works with version 25.5 where the definition of windows--sanitize-window-sizes looks something like this:
(defun window--sanitize-window-sizes (frame ...
1
vote
0answers
70 views
Defining a function that takes keyword arguments and a variable number of positional ones
I want to define a function that takes both keyword arguments (as in &key) and a variable number of positional ones (&rest). They should be independent of each other, the keyword list should ...
0
votes
2answers
55 views
How to raise an error when unrecogized keyword arguments are passed to a function?
With a function that uses keyword arguments using this style of function definition:
(defun some-name (&rest kwargs)
(plist-get kwargs 'example))
Is there a convenient way to ensure only ...
0
votes
3answers
213 views
Default argument when nil is provided
I'm writing a function which wraps org-export-as for use in html conversion of a file. In this function, I define the options for org-export-with-toc, org-export-with-section-numbers, and org-html-...
2
votes
1answer
111 views
How to introspect function & macro arguments in elisp?
Is there a programmatic way to access function/macro arguments,
Something like this, which returns the the arg count and true if it accepts any number of additional arguments.
eg:
(number-of-...
1
vote
1answer
45 views
Use Elisp macro instead of two function arguments?
Is the following sort of shortcut macro possible to implement?
(defmacro region-end-beg ()
"Replacement for '(region-end) (region-begin)' in source code"
(...))
So that
(buffer-substring (region-...
1
vote
2answers
112 views
Problem with giving inputs to a function programmatically
Some programs take user inputs, for example by calling the interactive function `sunrise-sunset', two arguments are taken from the user. Assume that the inputs are 0.0098 and 51.4934 (these are ...
0
votes
1answer
246 views
How to check whether an optional param was input?
I have a command with an optional argument whose value is a number.
I need:
If no input argument then use default value (1000) else use input arg.
(random t)
(defun insert-random-number-at-point(&...
5
votes
2answers
86 views
What is a good strategy to locating function arguments in a buffer?
I'd like to create a few routines for manipulating function arguments in buffers, which of course requires me to first locate the arguments. Suppose that I'm operating on a buffer with a programming ...
1
vote
2answers
72 views
advice-add FOR function dired-do-copy
I got a problem for an advice-add inside Dired's copy function (dired-do-copy).
My object is it to filter all marked files/directories in Dired, which should be copied to an other location within ...
2
votes
2answers
83 views
Arbitrary length lists as argument for interactive function
Say I have a defun with a dolist inside that I want to be able to pass a string that is then converted to a list with a length equal to the number of words in said string via the minibuffer, so ...
1
vote
1answer
216 views
Show constructor arguments for c++
Is there a package that can tell me the arguments for c++ constructor?
class T1 {
public:
T1(int x, int y);
};
T1::T1(int x, int y) {
std::cout << x+y << std::endl;
}
...
2
votes
1answer
208 views
Find out about arguments passed to functions
When I press C-h k C-SPC, Emacs shows me:
C-SPC runs the command set-mark-command (found in global-map), which
is an interactive compiled Lisp function.
It is bound to C-@, C-SPC.
(set-...
3
votes
1answer
108 views
Was Emacs launched with a filename argument?
Suppose I want Emacs to be configured differently depending on whether or not it was launched with a filename as an argument.
Is there a way I can deduce this as part of my init file?
One way is to ...
4
votes
3answers
400 views
Reflection on function argument signatures
Is there anything built into elisp for reflection on function argument signatures?
I have used (length (cadr (symbol-function #'my/function))), but this notably fails on built-in C functions.
I'm ...
4
votes
2answers
187 views
Calling a function with a shorter but unknown argument signature length
Is there a terse idiomatic way of calling a function in the manner of funcall (dereferencing function symbols) when that function may have a variably shorter function signature?
Say for example: a ...
2
votes
2answers
172 views
Can I pass an arbitrary symbol/keyword as a non-nil argument?
If a function takes a parameter whose only significance is in whether it's nil or non-nil, is there any reason not to pass it a well-named symbol to clarify what's going on in the calling code?
For ...
7
votes
2answers
122 views
Is there a way to only accept certain arguments to a function?
I want to write a function where the only two valid values for the input argument are "dag" or "rulegraph". Is there a way to specify that only these two arguments are accepted this in the elisp ...
1
vote
1answer
200 views
How does (org-agenda-todo arg) work? What does the argument mean?
By trial and error I have found that in org-agenda (org-agenda-todo 'done) marks the entry at point as "DONE".
Can you explain why?
How can I modify the argument to the org-agenda-todo function (or ...
0
votes
1answer
87 views
How can I use a var to provide multiple arguments to a function? [duplicate]
Here is a simple example in which I would like to replace
(start-process "ls" "*temp*" "ls" "-l" "-a" "-t" "-r") ; this works
with
(setq some-var ????) ; <-- Need to figure this part out
(start-...
2
votes
2answers
265 views
How to pass an argument from command to another command?
From the package Neotree, I want to bind a key, that moves to the upper directory.
The upper directory is always on the top with .. (up a dir). So I go to the first line of the neotree buffer, and ...
3
votes
2answers
5k views
Error: Wrong type argument: symbolp, (t)
I'm new to emacs and try to learn elisp. I've read some tutorials and try to build now my own customized emacs. Looking at this blog I want to write a similar script for automatically installing ...
12
votes
2answers
872 views
How to manipulate argument list in nadvice.el?
Following on from an answer to another question about the new advice system:
In old-style advice.el, it was possible to manipulate individual members of an advised function's argument list, without ...
11
votes
3answers
1k views
How to write a transparent "pass-through" function wrapper?
What I mean by a "transparent 'pass-through' function wrapper" is a function, let's call it wrapper, that returns the result from passing all its argument to some other function, let's call it wrappee....
8
votes
1answer
659 views
How to programmatically answer "yes" to those commands that prompt for a decision from the user?
I made a custom function that combines two functions of twittering-mode , twittering-favorite and twittering-native-retweet, however these two needs input from me by answering an yes or no question.
...
1
vote
1answer
96 views
How to figure out which parameters a function actually need?
I would like to insert the number 1, and then increase the number with calling
the function evil-numbers/inc-at-pt from the package evil-numbers.
So I went looking into the source code of the ...
2
votes
1answer
222 views
turn a list into a set of arguments for a function [duplicate]
I have a defun get-quotes with one mandatory and 2 optional arguments. I would like to do something like this:
(let ((articles
'("/home/matt/art/mice.pdf" '("/home/matt/art/cats.pdf" "Smith, ...
