Emacs customization - c++

I'm new to the whole Emacs thing, and one of the things that gets me is that out-of-the-box Emacs doesn't keep you within blocks when programming. I program in mostly Python and C++ and hitting enter sends the cursor back to column 1 on a new line rather than keeping you in the block you're working in. I managed to find this:
(add-hook 'python-mode-hook '(lambda () (define-key python-mode-map "\C-m" 'newline-and-indent)))
Which binds the enter key to newline-and-indent in Python mode, but how do I extend this to cover C/C++ mode too?

The following is from my init.el for xemacs, it might or might not work for emacs:
(add-hook 'c-mode-common-hook
'(lambda ()
(define-key c-mode-base-map (kbd "RET") 'newline-and-indent)))

Related

How to add to lists defined with c-lang-defconst?

I'm trying to add a C++ mode hook to add C++11 keywords to the appropriate keyword lists (which are defined in lisp/progmodes/cc-langs.el in the Emacs source code). As a minimal example, I started with c-modifier-kwds and tried adding the following to my .emacs file:
(add-hook 'c++-mode-hook
(lambda ()
(c-lang-defconst c-modifier-kwds
c++
(append '("thread_local" "noexcept")
(c-lang-const c-modifier-kwds))))
t)
(I copied the c-lang-defconst statement from this C++11 mode implementation. However, I don't want to create a whole new mode, I just want to add to the regular C++ mode.)
That didn't work (I didn't really expect it to, either). I also tried the following:
(add-hook 'c++-mode-hook
(lambda ()
(setq (c-lang-defconst c-modifier-kwds)
(append '("thread_local" "noexcept")
(c-lang-const c-modifier-kwds))))
t)
That didn't work either.
What's the right way to do this?
If there is no right way, what's a good hackish way to do this?

seeking autocomplete functionality in emacs

I am seeking a plugin to do autocompletion popup for c++ development in emacs. what I have tried are Cedet Semantics and the Autocompletion mode, they are pretty neat in terms of completing the variable and function names as long as I have a few words already. For example, I have a class named foo and a function that returns an integer 1
class foo{
int getInt(){return 1};
};
In the main method, so long as I started typing this
int main(){
foo bar;
bar.get...
}
the plugins have no problem popping up suggestions like bar.getInt(). However, what I am really looking for is something like in Eclipse, as soon as I press the "dot", possible choices could be generated for me. Is that possible in Emacs? Thanks
It depends on your settings of auto-complete & CEDET. It looks like that auto-complete is setup to show possible completions only after several characters will be typed. You can check value of the ac-auto-start variable - if this is a number, then auto-complete will be called after this number of characters.
Another important thing is a what is in your ac-sources variable - for work with CEDET you need to use ac-source-semantic-raw or ac-source-semantic completion source.
To automatic completion after . or -> you can try to use Semantic's built-in completion with something like:
(defun my-c-mode-cedet-hook ()
(local-set-key "." 'semantic-complete-self-insert)
(local-set-key ">" 'semantic-complete-self-insert))
(add-hook 'c-mode-common-hook 'my-c-mode-cedet-hook)
P.S. Had you seen my article on CEDET & C++?
I have found that cedet is really underwhelming, especially under cmake projects.
I would recommend using
https://github.com/Andersbakken/rtags
It underlines errors as you type as well as using smart completions. Just add this to your init file after obtaining the required emacs packages
(require 'rtags)
(require 'popup)
(require 'rtags-ac)
(setq rtags-completions-enabled t)
(rtags-enable-standard-keybindings c-mode-base-map)
(add-hook 'c++-mode-hook
(lambda ()
(setq ac-sources '(ac-source-rtags)
)))

c++ code folding with emacs/cedet

I would like to use the semantic code folding from the cedet package (emacs). I installed the 1.1 version and added the following lines to .emacs:
(load-file "~/software/cedet-1.1/common/cedet.el")
(require 'semantic-tag-folding)
(defun c-folding-hook ()
(global-semantic-tag-folding-mode 1)
(local-set-key (kbd "C-c <left>") 'semantic-tag-folding-fold-block)
(local-set-key (kbd "C-c <right>") 'semantic-tag-folding-show-block)
)
(add-hook 'c-mode-common-hook 'c-folding-hook)
Okay, when I now load a c oder c++ file, nothing happens when using the key bindings or directly running the corresponding commands. What's going wrong? Have I forgotten something?
First, you don't need to have (global-semantic-tag-folding-mode 1) inside defun - it's better to run this command once...
But I think, that main problem is that you hadn't enabled any Semantic feature (see this section in my article) - at least you need to call (semantic-load-enable-minimum-features) after loading of CEDET.
P.S. you code is working for me (I use semantic-load-enable-excessive-code-helpers in my setup)
try adding following line in your emacs config file after (load-file "~/software/cedet-1.1/common/cedet.el") line;
(semantic-load-enable-code-helpers) ; Enable prototype help and smart completion

Can I clean the repl?

I have played with a lot of code in a repl console, how can I clear it? I would like a fresh one without restarting it. Can that be done?
If you want to clear the current namespace of all temporary variables and functions you declared you can use this one liner (or make a function of it) :
(map #(ns-unmap *ns* %) (keys (ns-interns *ns*)))
or
(ns myutil)
(defn ns-clean
"Remove all internal mappings from a given name space or the current one if no parameter given."
([] (ns-clean *ns*))
([ns] (map #(ns-unmap ns %) (keys (ns-interns ns)))))
(ns mytest)
... make loads of junk ...
(myutil/ns-clean)
... great!!! I can now make all new junk ...
It does not claim to give you a squeaky clean namespace, just one with less of the junk which usually accumulates in a typical repl session.
Use with caution : do not pull the rug from under your feet!
If you are running the repl through a terminal window (eg: Terminal.app on MacOS or xterm/aterm/urxvt etc on linux) then you can type Control-L and it should clear the terminal window and give you a new repl prompt. However all macros/atoms you previously defined are still going to be in memory, so this is just a "Cosmetic" clear.
In EMACS/slime REPLs
C-c C-o clears the last output (in case you've typed something that gave a very long answer)
C-c M-o clears the whole thing
In GNOME terminals, you've got a menu option Terminal/Reset and Clear
The shorcut to clean the whole buffer : C-u C-c C-o
The shortcut to clean the last output : C-c C-o
Note, the old way was : C-c M-o
Also, cider-repl-clear-buffer (which is bound to C-ENTER s-c on my machine)
If you are using Emacs + nREPL, you can either:
Run Mx nrepl-clear-buffer or
Run Cc Mo
If the key binding is not enabled, run Mxnrepl-interaction-mode to enable it. You can find other useful shortcuts in nrepl.el and/or customize the key bindings to fit your needs.
Note: you can find all nREPL's key bindings in your system by running M-x v nrepl-mode-map and following the nrepl.el link.
I use the Emacs command cider-repl-clear-buffer via M-x. One might also use cider-repl-clear-output with a prefix argument: C-u C-c C-o.
It depends what you mean by 'clean'. To remove all namespaces within a 'package' you can use:
(mapv remove-ns
(map symbol
(filter #(.startsWith % "org.mycompany")
(map str (all-ns)))))
For users of the Cursive IDE plugin for IntelliJ IDEA who end up here, like me:
You can "cosmetically" clear the REPL (keeping your def'd symbols etc.) by clicking on this icon at the top of the REPL frame:
There's no default key binding for this, but you can easily add one by opening your preferences, navigating to Keymap > Plugins > Cursive, and adding a binding for "Clear output for current REPL".
Alternatively, you can right-click in the editor and access "Clear output for current REPL" via the REPL commands.

How do I forward `<Ctrl>-<Tab>` in Konsole?

I want to use intelligent tabbing in Emacs in C++ mode, but I also want to be able to insert a tab character when necessary. From other posts, I gather that the easiest way is to bind <Ctrl>-<Tab> to indent. However, it appears that Konsole in KUbuntu won't forward the <Ctrl>?
My current .emacs file contains:
(defun my-c-mode-common-hook ()
(setq c++-tab-always-indent t)
(setq tab-width 4)
(setq indent-tabs-mode t)
)
(add-hook 'c-mode-common-hook 'my-c-mode-common-hook)
(global-set-key [C-tab] 'self-insert-command)
So I believe that this will bind <Ctrl>-<Tab> to inserting a tab character. However, when I run:
<Ctrl>-h k <Ctrl>-<Tab>
Emacs only reports that I pressed the tab key. Is there some option to Konsole (which I have searched through to no avail) or global preferences in KUbuntu that I need to set so that the <Ctrl>- is also forwarded? (It certainly forwards all of the other <Ctrl>-blah commands.)
You can use Control-Q (quote, is what I think of in order to remember this), and then press your Tab key, and you'll insert a tab character. You can use Control-Q to insert any character sequence you need to. Hope this helps. :)
I had to solve the same problem and I found the answer here:
http://www.linux-archive.org/ubuntu-user/189410-equivalent-xterm-vt100-translations-string-gnome-terminal.html
What I did is the followings.
prepare my own konsole key bind customization file
~/.kde/share/apps/konsole/linux-custom.keytab
run konsole by specifying the keytab I customized
% konsole --keytab linux-custom
bind keys in Emacs
My binding in linux-custom.keytab is
key Tab +Control : "\E[4t" # control tab will generate esc [ 4 t
key Backtab : "\E[4s" # shift tab will generate esc [ 4 s
(I don't know any rule for assigning key code so I chose some code which are not yet used.)
In my Emacs customization file called from .emacs I put the following bindings
(define-prefix-command 'terminal-key-map)
(global-set-key (kbd "\e[") 'terminal-key-map)
(define-key terminal-key-map (kbd "4t") 'other-window) ;control tab
(define-key terminal-key-map (kbd "4s") 'other-window) ;shift tab
I also customized other keys such as control ;, control ', control =, etc. in the same way.