Circumflex accent before c IN LISP - lisp

I'm studing lisp and I found this: (zoom in)^C ^C , but the text don't explain it, and I searched "^C ^C" in other places but didn't found anything. Can someone here help-me?
(I'm studying english yet, sorry if I wrote anything wrong)

"^C^C" is not AutoLisp; that would be for/is the macro language for menus and such.
Caret-C does "mean" CTRL-C.
What it does in the macro language:
^c means: cancel
^c^c means: cancel twice.
In AutoCAD we hit the ESC key (twice to cancel a command). The ^C^C is "good practice". -i.e. Before we issue or start a new command we cancel any current command.
The equivalent in AutoLisp would be:
(command) (command)
or
(repeat 2 (command))

I think they refer to the control-character ctrl-c you enter after entering (zoom in) in the REPL.

As others have said, most likely it means Ctrl+C, especially if you're using emacs, where two Ctrl+C presses (usually written "C-c C-c" in the emacs convention, though) means "run this using the default interpreter" in some language modes.

If I'm not mistaken, ^C usually represents the "Ctrl+C" modified keypress.
It won't work in a console on Windows, as Ctrl+C also means "break (execution)", but if you press Ctrl+V, Ctrl+P, etc., you'll see what I mean.

Related

Emacs Prelude, Smartparens, and OsX

I'm using OSX 10.9, iTerm2, Emacs Prelude, and Clojure with all the modes that entails most relevantly, smartparens. Good so far.
The short version is: has anybody out there found a harmonious way to use all of this together with OSX Mission Control?
The longer version goes: I want to be able to use commands like sp-forward-slurp-sexp, which has a default keybinding of C-<right>, better known as the default OS-level shortcut for "switch Spaces right via Mission Control." I can re-map that fairly easily (say, to C-Shift-<right>) -- but now, I discover that C-<right> actually seems to be sending something like M-[1;4A. Instead of triggering sp-forward-slurp-sexp, you get sp-wrap-with-pair "[". Uhm.
I dug up this dissertation on re-mapping keys, which is very thorough, but also involves re-mapping rather a deal of stuff, then disabling the parts of paredit that are listening for the M-[ command. While this technically seems to work, I actually rather like having sp-wrap-with-pair enabled. Perhaps a better option would be to embrace the theoretically equivalent C-( -- except iTerm2 only interprets that as a literal 9, and C-) as 0. This SO post chews on this problem, and gets as far as a tantalizing comment suggesting that C-( and C-) simply be re-mapped to escape sequences that emacs can map back to C-( and C-) -- but frankly, I haven't a clue how to figure out what escape sequences those should be.
Bringing it all home: has anybody found a way to use all of these tools (Mission Control, iTerm2, Emacs Prelude, smartparens) together without having to re-wire or disable parts of some or most of them? Or: who has the most elegant re-wiring? Anybody figured out the C-)-to-escape-sequence-back-to-C-) trick yet?
Edit
Stabbing in the dark, I've done the following:
1. Set iTerm to send an escape sequence for the keyboard shortcut Ctrl-Shift-0 (C-S-)) of SPRTPRN.
2. Put this in my emacs config:
(define-key input-decode-map "\eSPRTPRN" [C-right-paren])
(global-set-key [C-right-paren] (kbd "C-)"))
...it does not work, but I've a hunch I'm getting closer. I think.
Edit, Again
I realized something: the notion that Shift doesn't work here doesn't make sense to me. At least on my emacs install, M-< and M-> jump to the beginning and end of a buffer, respectively -- and to use those commands, I have to actually press Meta-Shift-<. Huh.

list of emacs commands executed

I am using emacs and the auto-newline feature is not working as expected. I have a pretty large number of customizations done to my emacs. So it would be no wonder if one of the other customizations is not what auto-line is expecting. I would like to know if there is a way to know the list of commands (list of emacs commands) executed by emacs at a particular point, for e.g. when ctrl-s ctrl-c or in my case when auto-line feature is called.
edit : I think you have misunderstood the question. I would like to know what command emacs calls 'internally'.
I believe view-lossage is what you're looking for -- M-x view-lossage, or C-h l.
If you want to know what a keystroke is bound to, consider using describe-key, which is usually bound to C-h k.
Basically at this point, you need to bite the bullet and learn some Emacs-lisp. The debugger is what you are looking for to dig further into your problem (I use edebug). It's not just about seeing what functions get called, you also need to see the values of the relevant variables when those functions are called.
If you feel you're not up to it, then you can bi-sect your init file until you find the culprit, but at that point you still need some Emacs-lisp to investigate further.
To add to what #event_jr said --
What you seem to be asking is the history of the functions called by the command you last invoked. (You speak of Emacs "internal commands", but it seems you just mean functions.)
To get that history for any given command you invoke (e.g., by a key), use M-x debug-on-entry and then enter the command name. The next time you use that command, you can walk through its execution in the Emacs debugger (hit d to step, c to continue past a step).

Why do all keys start being interpreted as "." in Emacs?

I am running Emacs on a unix server, which I access using PuTTY. Occasionally, I accidentally type some combination of keystrokes that causes all future input to be interpreted as a period. I'm pretty sure this always starts when I'm in Emacs, but it continues after exiting (ctrl-xc still works), so if I exit and try to enter something at the prompt it just looks like "....".
I have no idea what I'm doing that causes this. Any ideas?
I agree with phils comment to the question. But In emacs whenever you like to see what you have just pressed, There is a C-h l which gives you the history of keystrokes

Emacs locks hard over PuTTY when £ is entered

I'm using emacs (21.4.1) via PuTTY (0.60) connected to a CentOS5.3 box with a UK keyboard. Whenever I enter the £ symbol emacs locks hard, making the whole putty window unresponsive and loosing all changes.
Edit:
Futher to pajato0's suggestion, I get the following message:
à (translated from £) runs the command self-insert-command
which is an interactive built-in function in `C source code'.
which is an interactive built-in function in `C source code'.
It is bound to many ordinary text characters.
So it looks like I need to rebind the key. How would one do this?
To determine what role, if any, Emacs is playing in your scenario, I would suggest that you try C-h k # where # is your pound key. If it hangs, then Emacs is not getting the key at all and you have a Putty/Windows issue most likely. If Emacs tells you the function binding then you have some hope of fixing it by changing the key binding. My best guess is that Putty is capturing the key and sending it to Windows which is dropping the ball.
You could try another ssh client to see if it is putty-specific. I tend to just run
startxwin.sh # from a MinGW rxvt terminal
after which an xterm pops up in which I do
ssh -X some.unix.box # from the new xterm
after which I fire up a tabbed terminal emulator in which I keep several sessions 'forever'. And my US keyboard has no Pound sign so no way for me to test your issue...
I would look at the character set translation that putty is performing (window->translation in settings). It could be that the character code that is being sent for a pound symbol (don't have a UK keyboard...) locks up the terminal somehow, or that the character that is being returned in response to the keypress is causing some similar behavior (e.g. waiting for the completion of a code point).
You might want to try it with everything set to UTF-8 (charset/locale on linux side, and on Putty translation), to minimize the chances of confusion...
In response to your question "how does one rebind a key": use the define-key function, e.g.
(define-key global-map [S-Home] 'beginning-of-buffer)
The hard part is figuring out how to represent your key and then choosing a suitable function. For example, you might do something like:
(defun make-euro ()
"Euro")
(define-key global-map # 'make-euro)
But I would also suggest that you file a bug since if trying to self-insert your # key causes Emacs to hang, that is clearly Emacs breakage that should get fixed.

What to teach a beginner in Emacs? [closed]

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If you had a 10 minute hands-on session to teach someone Emacs, what would you show them?
Start emacs: emacs
...
Quit emacs: C-x C-c
What else would you have them do between starting and quitting Emacs, while you stood behind them?
If I had only 10 minutes, I would not teach them any shortcuts at all. All the common shortcuts are available next to the corresponding commands in the menus; those the users can discover for themselves.
The most important things to teach are those that will enable the users to discover/learn by themselves:
That one can quit Emacs with C-x C-c, or File->Quit. When stuck, one should type C-g, and, if that doesn't work, ESC ESC ESC. [This is probably the single most useful advice to prevent total frustration with Emacs, trust me.]
The tutorial: Help->Emacs Tutorial, or C-h t. [This is not a terribly useful shortcut to remember; given how few times one reads the tutorial over the course of one's life...]
The concept that every keystroke in Emacs is bound to a function, and all that Emacs does is execute functions one after another. That there are more functions than can possibly be bound to keys, and functions without a keystroke can be invoked with M-x function-name.
That one can discover what function a particular key invokes with C-h k [keystroke]. Make the user walk through a few of those (including the amusing fact that typing a letter is not special and just invokes self-insert-command, so if one wanted, one could bind the letter 'z' to send email instead :D)
That one can search for possibly useful functions with C-h a (or M-x apropos-command), e.g. C-h a paragraph shows all the commands to do with paragraphs, including what shortcuts will take one to the end/beginning of a paragraph. And that C-h w command-name will tell you if the command is bound to some keystroke or not. [Make them walk through this to discover what the key for undo is -- usually they'll try C-z and it does something annoying :)]
That you can read detailed documentation about what a function does with M-x describe-function (C-h f). That Emacs has great documentation about most things; and M-x apropos-documentation (C-h d) is a great way of discovering stuff.
That one's settings are stored in .emacs, and that one can glean some things by looking at that file even if one don't understand Emacs Lisp.
That one can usually find all keystrokes that "complete" a particular set of keys by typing C-h after it, e.g. 'C-x C-h' will show all the shortcuts starting with C-x; C-h C-h is particularly useful; C-c C-h is useful for mode-specific commands such as when in java-mode or c++-mode or LaTeX-mode, etc. (Hmm, "modes"...)
That when stuck, one can search on http://www.emacswiki.org/. (Or ask a question in the #emacs IRC channel on Freenode, or post to gnu.emacs.help.)
This should fit in 10 minutes, and it's the most important stuff, I think. I wouldn't overload with too many shortcuts to remember; that's pointless anyway -- if the users know how to discover shortcuts, they'll find out shortcuts for whatever they use most frequently. Do have them write down the names of these commands, though, and also about Emacswiki etc.
The important thing is to show them how powerful Emacs is and how universal its model is (all those jokes about it being an operating system are not just jokes). If you just show a bunch of arcane shortcuts to do things they can already do in other editors, Emacs won't seem worth all the trouble. In the same spirit, I also wholly support Anton Nazarov's answer of showing them what Emacs can do (AucTeX if they use LaTeX, etc.) for their specific purposes. Then they can judge for themselves whether Emacs is worth learning, and learn using all the above.
Show them how to start the tutorial: C-h t
C-x M-c M-butterfly
I'd show the most important for that novice user mode.
For example, when I show Emacs to my friends at the faculty of physics, I show them AucTeX with preview-latex and RefTeX. Also iMaxima is great.
If I have to show Emacs to software developers I show them something like JDEE or Python mode with Ropemacs.
Tetris, tramp and w3m can be used to give the idea that Emacs can do everything :)
Then I'd show how to start the tutorial and give link to EmacsWiki.org
i think you show him how
to open and save files
to kill/switch buffers
to switch/kill/split windows
to select a range.
And tell him about M-x . Tell him he write those steps down somewhere. I think basic navigation can be done using arrow keys. Now this is all he needs.
If he knows about M-x , he can easily find search, replace and other stuff.
When giving emacs examples it's never enough to only give the key binding since that can and does vary. C-x M-c is undefined on my system.
When I start XEmacas, until I press a key it alternates between two screens. One of them has the following:
XEmacs 21.4 (patch 21) "Educational Television" (cygwin, Mule) of Tue Dec 4 2007 on vzell-de
`C-' means the control key,`M-' means the meta key
Information, on-line help:
XEmacs comes with plenty of documentation...
M-? F: read the XEmacs FAQ (a capital F!)
M-? t: read the XEmacs tutorial (also available through the Help menu)
f1: get help on using XEmacs (also available through the Help menu)
M-? i: read the on-line documentation
M-x describe-project: read about the GNU project
M-x about-xemacs: see who's developing XEmacs
I would ask that someone to read it out aloud, make sure they understand what it says and then give them, to use in case of emergency, my cell-phone number and a first-aid kit.
I would show the shortcuts for the most common operations such as:
Save: ctrl-x-s
Save as: ctrl-x-w
Open/find file: Ctrl-f
Undo: ctrl-_
Kill buffer: ctrl-x-k
Switch to buffer: ctrl-b
Fill paragraph: M-q
And copy/cut and paste:
Set marker: ctrl-space
Cut: ctrl-w
Copy: M-w
Cut line: ctrl-k
Paste: ctrl-y
Open a file,
Save a file,
Basic navigation,
Set mark, copy, cut and paste,
Show undo and kill ring,
Show C-g,
Show search and replace,
Split window and move to other window,
Switch to other buffers,
Show Tutorial,
Explain Info,
Show dired to:
open some file,
run a command to compress another file,
open, edit and save the compressed file,
open a directory on a remote host,
open & save some file on the remote host,
copy some file from the remote host.
Open a shell and run some long output command and navigate in the buffer.
Learn to use help C-h C-h
Do the tutorial exercice.
Kill something, and another thing, and a third one, then C-y to yank it, and M-y to cycle the kill ring. Big "Woah" factor, quick and cheap. Then tell them it works in their daily shell.
Navigate in the buffer with the mark ring. C-u C-SPC (space) takes you to where you were before and, repeated, cycles though the 16 last positions, regardless of edit state.
You know when you sheepishly undo things just to get "where you were before" ? There you go.
This is a killer emacs ninja trick. Everybody should know it ASAP.
I think the first thing to ask before trying to teach them something is "what do they want to get out of learning Emacs?" AND, are you trying to sell them on the idea of learning Emacs or are they already committed.
If they are a programmer and are looking for a new development environment, show them ECB, how tags work, etc? If they are looking for a general text editor, show them M-x re-builder. If they are looking to write documents quickly and publish them eventually, show them org-mode with HTML and LaTeX exports.
Besides what had been mentioned already I would also show them M-x global-set-key after having showed M-x in general and M-x apropos.
I would tell them that the point of Emacs is that it is infinitely customizable and that one should personalize it to suit one's preferences. I would tell them to try out the standard key bindings first and the advantages of them showing up in Bash, OS X, etc.
C-g
Copy paste
Split Windows
M-x
Apropos
Describe Key
Describe Command
Open files
Switch Buffers
The language-specific development environment, including the debugger and the REPL.