elisp

I'm having a hard time understanding exactly how macro expansion works. What is the difference in how the elisp interpreter handles these two snippets of code? (defmacro foo (arg) (message "arg is: %s" arg)) (foo "bar") and: (defmacro foo (arg) `(message "arg is: %s" ,arg)) (foo "bar") You example may be confusing because message both displays a message and returns it. strings (like "bar") are self-evaluating. Instructive Example (defconst zzz 123) (defmacro zzz1 (arg) `(insert (format "arg is: %s" ,arg))) (defmacro zzz2 (arg) (insert (format "arg is: %s" arg))) Evaluate the code above using C

I'm using Emacs 24 on Windows to write some R code. Up until about 30 minutes ago, whenever I would write a new function, ESS would automatically indent the lines following the function declaration and pressing the tab key on a new blank line would jump me to the appropriately indented starting position inside the declaration. EG: foo <- function() { first line started here second line here. .etc } Now, it is hard wrapping everything to the left, and not responding by automatically indenting after the function declaration or when I hit the tab key. foo <- function() { first line second line }

I'm a newbie to programming, so please bear with me here... I have a directory full of files called "foo01.txt", "foo02.txt", etc. and a function called MyFunction . I want to open each file as a buffer, run MyFunction on it, write the buffer to its file, kill the buffer and move on to the next file in the series until all the files are done. I think all the pieces I need to do this are described in the Cookbook ( http://emacswiki.org/emacs/ElispCookbook ) but I'm not really understanding how to put it all together. Thanks! Answer If you're looking for an answer in pure elisp, you could do

The default behavior of gist-region is to leave the description blank. To set the description, it is necessary to switch to the gist-list buffer and then use the function gist-edit-current-description to set the description . I would like to be able to set the description at the same time that the gist is created, without switching to the gist-list buffer. A mini-buffer prompt that defaults to the buffer-name would be the preferred method of handling this. How can this be accomplished programmatically? Here are the two main functions in gist.el that are responsible for the behavior described

I am finding myself editing a lot of files that are read-only. I usually hit C-x C-q to call toggle-read-only . Then I hit C-x C-s to save and get, File foo.txt is write-protected; try to save anyway? (y or n) After hitting y , the file is saved and the permissions on the file remain read-only. Is there a way to shorten this process and make it so that simply saving a file with C-x C-s does the whole thing without prompting? Should I look into inserting chmod in before-save-hook and after-save-hook or is there a better way? Adding a call to chmod in before-save-hook would be clean way to

Is it possible to make emacs interpet an fn key as a modifier key? Can I bind f6, f.ex. to hyper? I had this: (setq ns-function-modifier 'hyper) ; set Mac's Fn key to type Hype And tried to do this: (setq <f6> 'hyper) But the latter did not work. I'd prefer not making the OS as a whole see f9 as some sort of modifier key (making it possible to more easily use the function keys for different purposes in other apps). Edit: It seems like one possible solution is to bind f9 to C-x @ h but when I try to get the documentation for the function C-x @ or C-x @ h I don't get any result. (It only shows a

Is there a (non-interactive) function in emacs lisp that replaces a matched regex in an arbitrary string? i.e. (sub regex search-string replace-string) as in (sub "[^.x/]" "beef./xxfoo" "") ;; => "./xx" Yes, see function replace-regexp-in-string . Simple as that. And to replace matching text in a buffer, you have replace-regexp . The replacement does not need to be a literal string, but can involve retrieving parts of the regexp match and other manipulations. Use C-h f to see the doc for these functions. 来源： https://stackoverflow.com/questions/27235293/non-interactive-emacs-regex-substitute