In Emacs, how can I display tabs like this?
Some py files use tab keys,and sometimes it's very ugly!
You can set how the tab character is displayed in a buffer by using aset on the buffer-display-table. An example would look something like this:
(aset buffer-display-table
?\t ;;Character to replace
[?> ?- ?- ?- ?- ?- ?- ?-]) ;;Characters to replace with
If you want to specify a string instead (since it's a bit more readable), this is the shortest way I've found to do it (if anyone knows a better way to convert a string to a char vector, please let me know).
(aset buffer-display-table ?\t
(map 'vector 'string-to-char
(split-string ">-------" "" t)))
You can undo this change by setting the value back to a tab character:
(aset buffer-display-table ?\t [?\t])
This only modified the current buffer, so you'd need to use a hook to call it when you enter python mode. Alternatively, you could use standard-display-table instead, which would replace it anywhere that doesn't have it's own display table.
Related
I'd like commands like alt-backspace, alt-B, alt-F etc. treat ranges of at least maybe 4 spaces as a word, or perhaps if it's a range of whitespace that includes a newline...
Any pointers for making such a modification?
Perhaps a simpler request: add underscore to set of characters recognized as a word, as C++ symbols often have underscores.
If you don't have subword-mode enabled, you can change the syntax of the characters you want to jump over, eg. _ by wrapping any command you want in with-syntax-table, here wrapping forward-word,
(defvar my-syntax-table
(let ((tab (copy-syntax-table)))
(modify-syntax-entry ?_ "w" tab)
tab))
(define-advice forward-word (:around (fn &rest args) "modified-syntax")
(let (inhibit-field-text-motion)
(with-syntax-table my-syntax-table
(apply fn args))))
With subword-mode, it looks like you could modify the subword-forward-regexp and subword-backward-regexp variables to include the additional characters, eg. four spaces could be an addition of " \\{4\\}".
I'd like to quickly generate text in a buffer that looks like this:
(fact "This is some text which will hang out
only on this part of the screen, ideally
automatically flowing to the correct
margins as I type."
(+ 1 1) => 2
;; more Clojure tests...
)
I have an Elisp keybinding which quickly spits out a starting template and puts my cursor in the right place:
(global-set-key "\C-of" (lambda ()
(interactive)
(insert "(fact \"\"\n\n )")
(backward-char 6)))
Now, when I am typing in the string portion ("This is some text..."), it'd be awesome if I could get Emacs to automatically flow text to the "correct" margins. Is there some way Emacs can be made to adjust margins and wraparound behavior based on where you're typing? At least, the first time you are typing there?
Barring that, for a given selection of text, how can I do the equivalent of fill-region, but with the desired left and right margins? Currently fill-region deletes all space between fact and "This is...., and left-justifies the rest.
There might be a simpler way that I'm overlooking now, but I would just do this:
Configure the text block in a temporary buffer, by doing this there:
a. Set fill-column to the width of the text block that you want.
b. Put the text at the beginning of the line, i.e., not indented.
c. Fill the text.
d. Use indent-rigidly to indent the text to the column you want, except for the first line.
Insert into your target buffer (fact followed by the indentation you want for the first line of the text block. Then insert the contents of the temporary buffer. Then insert whatever other text/code you need.
IOW, I would separate filling the text block from indenting it.
The following seems to work for the moment for my alternative (weaker) case:
;; Set up Midje fact with mark inserted at beginning of comment text
;; (refill as needed in appropriate columns, using C-oF).
(global-set-key "\C-of" (lambda ()
(interactive)
(insert "(fact \"\"\n\n )")
(backward-char 6)
(set-mark (point))))
;; Perform the refill operation to properly reformat the text string
;; in a Midje fact, started with C-of:
(global-set-key "\C-oF" (lambda ()
(interactive)
(set-left-margin (mark) (point) 37)
(fill-region (mark) (point))))
I expect I'll have to tweak this as I get experience using it, but it is pretty close. Still, it'd be nice to figure out how to have this happen automatically, while I'm typing inside the string.
I am writing R Markdown (.Rmd) file with a lot of LaTeX contents. The major mode is Markdown-mode. But what I want is that: when I try to type some LaTeX commands between $$, I want to automatically turn on the LaTeX major mode, and after I end the LaTeX chunk with $$ or $, it can turn off LaTeX major mode and turn on Markdown-mode again.
The inline format for LaTeX is
$\alpha$
The equation(displaymath) format for LaTeX is
$$
\alpha + \beta
$$
A similar example is when I was writing a .Rnw file, the major mode is LaTeX, but when I edit the R
code chunk:
<<>>=
y <- 1000
#
between <<>>= and #, it turns on the ESS mode.
So can anyone help me to do the similar stuff in Markdown-LaTeX case? Thanks!
Updates after Inaimathi's answer:
Following http://www.emacswiki.org/emacs/MultipleModes#toc6, I need to modify the two-mode-mode.el
- (if (string= to-mode mode-name)
+ (if (string= to-mode major-mode)
and for emacs 24
- (make-local-hook 'post-command-hook)
Then, by Inaimathi, I put the following in my .emacs:
(require 'two-mode-mode)
(setq default-mode (list "Markdown" 'markdown-mode)
second-modes (list (list "LaTeX" "\\\[" "\\\]" 'latex-mode)))
Then the major mode switches between \[ and \].
If you're ok with your major mode changing as you navigate, two-mode-mode should be able to do what you need. You need to include that .el, then add a block that looks something like
(require 'two-mode-mode)
(setq default-mode (list "Haskell" 'haskell-mode)
second-modes (list (list "Markdown" "\[markdown|" "|\]" 'markdown-mode)))
to your ~/.emacs. The above is what I do to highlight markdown blocks while editing Elm code. For your particular use case, you'd probably need
(require 'two-mode-mode)
(setq default-mode (list "Markdown" 'markdown-mode)
second-modes (list (list "Latex" "\$\$" "\$\$" 'latex-mode)
(list "Latex" "<<>>=" "#" 'latex-mode)))
Instead. This is completely untested, includes no warranty, etc etc.
Ideally, what I'd like in that situation is for the rest of the buffer to keep markdown-mode highlighting, and have just the particular region get highlighted in latex-mode or whatever. Near as I can tell, there isn't a ready, general solution for that, but if you're up for some Elisp hacking, you could give this a read and see what you can come up with.
looking for an equivalent cut and paste strategy that would replicate vim's 'cut til'. I'm sure this is googleable if I actually knew what it was called in vim, but heres what i'm looking for:
if i have a block of text like so:
foo bar (baz)
and I was at the beginning of the line and i wanted to cut until the first paren, in visual mode, I'd do:
ct (
I think there is probably a way to look back and i think you can pass more specific regular expressions. But anyway, looking for some emacs equivalents to doing this kind of text replacement. Thanks.
Here are three ways:
Just type M-dM-d to delete two words. This will leave the final space, so you'll have to delete it yourself and then add it back if you paste the two words back elsewhere.
M-z is zap-to-char, which deletes text from the cursor up to and including a character you specify. In this case you'd have to do something like M-2M-zSPC to zap up to and including the second space character.
Type C-SPC to set the mark, then go into incremental search with C-s, type a space to jump to the first space, then C-s to search forward for the next space, RET to terminate the search, and finally C-w to kill the text you selected.
Personally I'd generally go with #1.
as ataylor said zap-to-char is the way to go, The following modification to the zap-to-char is what exactly you want
(defun zap-up-to-char (arg char)
"Like standard zap-to-char, but stops just before the given character."
(interactive "p\ncZap up to char: ")
(kill-region (point)
(progn
(search-forward (char-to-string char) nil nil arg)
(forward-char (if (>= arg 0) -1 1))
(point))))
(define-key global-map [(meta ?z)] 'zap-up-to-char) ; Rebind M-z to our version
BTW don't forget that it has the ability to go backward with a negative prefix
That sounds like zap-to-char in emacs, bound to M-z by default. Note that zap-to-char will cut all the characters up to and including the one you've selected.
For example if I have the text:
Sum of items is (+ 1 2 3)
I want to move to the end of the line, evaluate the expression and replace it with the result, so that it reads:
Sum of items is 6
With the cursor at the end of the line, C-u C-x C-e will insert the value of the preceding parenthesized expression into the buffer. You could do that, then manually back up and delete the original expression. If that's too much work, here's a command that evaluates the preceding expression and replaces it with its value:
(defun replace-last-sexp ()
(interactive)
(let ((value (eval (preceding-sexp))))
(kill-sexp -1)
(insert (format "%S" value))))
Related to this, you might like Luke Gorrie's "lively.el", which provides live replacement of emacs lisp expressions within a text buffer. It's a neat hack.
I was having a go at a solution for this when I came across one in a Google search result.
(defun fc-eval-and-replace ()
"Replace the preceding sexp with its value."
(interactive)
(backward-kill-sexp)
(prin1 (eval (read (current-kill 0)))
(current-buffer)))
http://emacs.wordpress.com/2007/01/17/eval-and-replace-anywhere/
replace-regex functions can execute lisp to generate the replacements.
In the trivial instance where the sexp in question is on a single line, and is the only thing containing parenthesis, then you could match "(.+)" and replace with "\,(eval (read \&))".
If you are using emacs starter kit by technomancy there is "esk-eval-and-replace" function which evaluates the elisp sexp and replace them. Its bind to C-c e by default.
look to the function eval-print-last-sexp, you can build something using it
My emacs-fu isn't so strong, so I don't know if there's a single command to do this, but you can make yourself a (somewhat fragile) macro for it ... drop these lines in your .emacs:
(fset 'eval-sexp-in-place
[?\M-x ?e ?v ?a ?l ?- ?p ?r ?i ?n tab return ?\M-^ ?\M-^ ?\C-\M-b ?\C-\M-k ?\C-d])
(global-set-key [(control x) (control a)] 'eval-sexp-in-place)
This works fine, but there's one issue with it: you need to be at the end of the sexp (i.e. after the last right paren) to get it to work.
Also, I picked a random unbound key (C-x C-a) -- feel free to change that to something more to your liking.