So I am playing with Coq using Emacs as the IDE. Both proof-general and company-coq are installed and load correctly.
Then I open dummy whatever_name.v file and define recursive function using the Fixpoint keyword.
Then I run coq-Check on it and get:
> Check addnm .
Error: The reference addnm was not found in the current environment.
However, for example, Inductive unit : Set := tt. works perfectly well.
What am I doing wrong?
I have the impression you did not ask Coq to read the addnm definition. Try pressing C-c C-n on your Coq buffer. This should instruct Proof General to send in the next command to Coq for processing. You should see your buffer progressively turning a different color as the commands are sent. Once the definition of addnm is highlighted, you should be able to check it (C-c C-a C-c).
(The reason unit still works is that its definition is automatically loaded when you start Coq in Emacs.)
In lecture 6 of the DeepSpec 2018, the lecturer Checks the definition of
string_dec
obtaining:
string_dec
: forall s1 s2 : string, {s1 = s2} + {s1 <> s2}
Then he goes on to see the definition of +, but before, he disables in CoqIde the printing of notation. So that sumbool is printed. This last symbol can be checked.
How can I do the same thing with Proof General?
You can use the menu, Coq > OPTIONS > Set Printing All.
You can also issue the command directly, typing Set Printing All. and evaluating it in your buffer before running the Check command. This also gives you access to Unset Printing Notations to only disable printing notations (which is something you can do with the menu in CoqIDE). When you're done you can just delete this command, which will undo its effect.
Finally, you can also directly use Coq > OTHER QUERIES > Check (show all) on string_dec.
In python mode, when I forward-word. The cursor jumps from H to d (Hello_World). But in another mode(shell-mode or c-mode), the cursor jumps from H to _.
I want the result which i get in Python mode, even in the other mode. What should I do?
PS: I saw a similar question before, I have searched, but I could't find it.
I think you're looking for this:
(modify-syntax-entry ?_ "w")
Underscores will be treated as part of a word. This command will change the syntax table of the mode you're currently in. AFAIK there's no way to change syntax globally. However, you could try modifying the standard syntax table. Most major modes inherit the standard-syntax-table.
(modify-syntax-entry ?_ "w" standard-syntax-table)
If that doesn't work, I guess you have to add mode-hooks for all modes you're using and modify their syntax tables individually.
Things got a little simpler since Emacs 24.4. There's now a M-x superword-mode that has the desired effect.
What would be the easiest way to have the same kind of behavior that is in vim for the word back and forth navigation? In vim when you press "w" it moves a cursor forward one word, where word consists of a sequence of letters, digits and underscores, or a sequence of other non-blank characters, separated with white space (spaces, tabs, eol). In emacs on the other hand it skips until the end of the next word and the word is defined per mode in the syntax table.
For example: having a cursor at the beginning of the line following shows where vim put a cursor when you do forward-word ("w") operation:
opt1.arg = opt2.arg
^ ^^ ^ ^ ^^ ^
In emacs it is like:
opt1.arg = opt2.arg
^ ^ ^ ^ ^
It really depends on a one's preference, but I tend to like the vim style better and I was wondering what is the easiest way to have the same in emacs. I guess I'm not alone who switched from vim to emacs so perhaps someone already has a solution, ideally for the kill-word and backward-kill-word as well :)
I know you can get something similar by combination of M-f, M-b etc., but that is not the point. I also don't want to start a discussion which approach is better - the topis is well discussed in here.
You can actually use 'viper-forward-word
(require 'viper)
(global-set-key (kbd "M-f") 'viper-forward-word)
(global-set-key (kbd "M-b") 'viper-backward-word)
Mostly a duplicate of this, which says:
(require 'misc)
Then bind whatever keys you want to forward-to-word and backward-to-word. For killing, create some simple functions that wrap these functions and do kill.
I don't know why jpkotta's answer was deleted, but here it is again:
I have a minor mode that changes word-based commands to operate on syntax changes (and also CamelCaseSubwords). It may be a bit too fine-grained for some tastes, but I find I basically ever use single character movement anymore.
https://bitbucket.org/jpkotta/syntax-subword
# mods, I don't know why this answer would be deleted, so if you choose to delete this answer too, I'd appreciate an explanation.
I decided that I was ready to try something new, after a few years of using gEdit for most of my coding needs, and try to learn using Emacs. I knew this would be difficult, as I have heard how complex Emacs can be, but I was lured by its power. The hardest thing has been getting used to writing ELisp in the .emacs file to change things about the editor. I can't currently do it myself, but I have found a few helpful snippets here and there to change some options.
One thing I have been having a lot of problems with is getting Emacs to remember the text I have selected after a command. For instance, I commonly highlight a section of code to mass indent it. However, if I do this in Emacs, it will move the selected text only once before unselecting all of the text. Does anyone know a way around this?
Anyway, I apologize for what seems to me to be an easy question, but after an hour of Google searching and looking around here on SO, I thought it was worth asking. I have a few more questions about Emacs, but I will save them and ask separately after I get this straightened out. Thanks!
UPDATE
A few people have asked about what mod I am using and what type of text I am entering. While I don't know much about Emacs modes, I am editing a pure text file at the moment. Something like this:
Hello, I am a simple text file
that is made up of three separate
lines.
If I highlight all three lines and hit TAB, I get this:
Hello, I am a simple text file
that is made up of three separate
lines.
This is great, however, if I use C-x C-x like some suggest below to reselect the text and hit TAB again, I get this:
Hello, I am a simple text file
that is made up of three separate
lines.
I hope this helps!
FWIW, here is the reason for the behaviour of your newly-added example. (I'm not 'solving' the issue here, but I'm posting it to demystify what you're seeing.)
This was determined with emacs -q which disables my customisations, so the following is default behaviour for emacs 23.2.
You are in text-mode. You should see (Text) or similar in the mode line at the bottom of the screen, and C-h m will tell you (under the list of minor modes) "Text mode: Major mode for editing text written for humans to read." Emacs decides (by way of the auto-mode-alist variable) that it should switch to text-mode if you visit a filename matching certain extensions (such as .txt).
In text-mode pressing TAB with a region highlighted causes indent-according-to-mode to be called on each line of the region in sequence. The slightly convoluted path to finding this out starts at C-h k TAB, which tells us that TAB is bound to indent-for-tab-command, which in this instance calls indent-region -- that function name is not stated explicitly in the help, but can be seen in the code -- which checks the buffer-local indent-region-function variable, which is nil, and: "A value of nil means really run indent-according-to-mode on each line."
indent-according-to-mode checks the indent-line-function variable, which has the buffer-local value indent-relative.
Use C-h f indent-relative RET to see the help for this function. (Read this).
Although you probably won't yet have had the experience to know how to check all that (or necessarily even want to!), and fully understand everything it tells you, this is an example of how the self-documenting aspect of Emacs enables a user to figure out what is going on (which then makes it feasible to change things). I essentially just used C-h k (describe-key), C-h f (describe-function), and C-h v (describe-variable) to follow the documentation. Looking at the source code for indent-for-tab-command was as simple as clicking the file name shown as part of its help page.
I suggest doing the following to help see what is happening when indent-relative runs on each line:
M-x set-variable x-stretch-cursor t
M-x set-variable ruler-mode-show-tab-stops t
M-x ruler-mode
Now for each line in turn, put the cursor at the very start of the line and press TAB. You'll end up with all three lines indented to the first tab-stop ('T' in the ruler).
Now repeat this -- again, ensure you are at the very start of each line, in front of the existing indentation.
The first character of the first line (which is currently a tab) is once again indented to the first tab-stop, as there is no preceding line for it to examine.
Next, the first character of the second line is indented to match the position of the first non-white-space character of the preceding line. Because the first character of the second line is also a tab, the actual text of the second line is pushed one tab further along.
The third line follows suit. Its first tab character is lined up with the first non-white-space character of the second line, with the same relative effect as before, giving you the final state in your example.
To emphasise, note what happens if you now put enter the line "a b c" above the existing lines, then move back to the start of the next line (what was previously the first line) and press TAB. The first tab character will now be indented in line with the 'b'. Provided that the indent-tabs-mode variable is true (meaning you have actual tab characters), then this will have no practical effect on the position of the words in the line, as 'indenting' a tab with spaces will not have an effect until the number of spaces exceeds the width of the tab (but that's another kettle of fish entirely!)
All this really means is that text-mode in Emacs doesn't behave the way you'd like it to in this situation. Other major modes can do completely different things when you press TAB, of course.
As is invariably the case with Emacs, things you don't like can be changed or circumvented with elisp. Some searching (especially at the Emacs Wiki) will frequently turn up useful solutions to problems you encounter.
Try typing C-x C-x after Emacs unselects it.
Then, instead of hitting tab (I never knew that tab does what you said! That's totally whacked.), do M-8 C-x C-i. Pity it's so many keys, but it ought to do what you want -- namely, shove everything over 8 columns. Obviously replace the M-8 with something else if you want some other number of columns.
What I usually do is simply type C-x C-x (exchange-point-and-mark) after a command that deactives the region.
How are you indenting, and in which mode?
The indentation rules in any programming mode should generally just get it right. (If they don't, that's probably more indicative that you want to configure the rules for that mode differently, but I suspect that's a different question which has been asked already).
If you're in text-mode or similar and just using TAB, then I can see the problem.
Note that if you're using indent-rigidly (C-x C-i, or C-x TAB which is the same thing) then you can repeatedly indent the same region simply by repeating the command, even if the highlighting has disappeared from view.
You can also use a prefix arg to indent-rigidly to make it indent many times. e.g. C-u C-u C-x C-i (easier to type than it looks) will indent 16 spaces (4 x 4, as the prefix arg defaults to 4, and it multiplies on each repeat). Similarly, M-8 C-x C-i indents 8 spaces. This is fine in some circumstances, and way too cumbersome in others.
Personally I suggest putting (cua-selection-mode 1) into your .emacs and using that for rigid indentation. Trey Jackson made a handy blog about it. With this, you can C-RET to start rectangle selection, down as many lines as you need, TAB repeatedly to indent the lines, and C-RET to exit the mode.
While the rectangle is active, RET cycles through the corners. For left-hand corners, typing inserts in front. For right-hand corners, typing inserts after. For the single-column rectangle, bottom counts as 'left' and top counts as 'right' for this purpose.
Trey's blog lists all the available features (or look in the source file: cua-base.el)
Be warned that indentation in Emacs is generally an unexpectedly complicated topic.
You can do this with something like the following:
(add-hook 'text-mode-hook (lambda ()
(set (make-local-variable 'indent-region-function)
(lambda (s e)
(indent-rigidly s e tab-width)))))
Then selecting a region and hitting TAB. will indent the region by a tab-width. You can then exchange point and mark with C-x C-x and hit TAB again to repeat.
I do, however, agree with the previous answers that suggest using indent-rigidly directly.