Vim smart tabs inside an if statement - vim

I'm using Vim's SmartTabs plugin to alingn C code with tabs up to the indentation level, then spaces for alignment after that. It works great for things like
void fn(int a,
________int b) {
--->...
Tabs are --->, spaces are _. But it doesn't seem to work so well for cases like
--->if(some_variable >
--->--->some_other_variable) {
--->...
In the case above, Vim inserts tabs on the second line inside the parentheses. Is there a way I can modify what Vim sees as a continuation line to include cases like this, so I get:
--->if(some_variable >
--->___some_other_variable) {
--->...

If there's an indentation style that would both allow flexible indentation width according to one's preferences, and consistent alignment, your suggested scheme would be it. Unfortunately, this style requires some basic understanding of the underlying syntax (e.g. whether some_other_variable is part of the line-broken conditional (→ Spaces) or a function call within the conditional (→ Tab)), and this makes implementing it difficult.
I'm not aware of any existing Vim plugin. The 'copyindent' and 'preserveindent' options help a bit, but essentially you have to explicitly insert the non-indent with Space yourself (and probably :set list to verify).
I don't know about that other Editor, but the situation is similar for most other inferior code editors. Without good automatic support, this otherwise elegant style will have a hard time gaining acceptance. I would love to see such a plugin for Vim.

Related

Faster way to type control flow statements (in C and php etc)?

I am new to Vim and I need to speed up my typing for this kind of statements.
if (a == 'e') {
foo();
}
In other text editors, I usually type if() {} first and then insert the text in to the parenthesis and curly braces. If I do this in Vim, I need to switch back to normal, move cursor to middle of () then middle of {}... switch between i and esc ...
What is your suggestion on typing this kind of syntax for Vim beginner? I would be grateful if you can show me the commands for that example step by step.
This is a job for snippet expansion. Take a look at SnipMate or UltiSnips.
snippets are like the built-in :abbreviate on steroids, usually with parameter insertions, mirroring, and multiple stops inside them. One of the first, very famous (and still widely used) Vim plugins is snipMate (inspired by the TextMate editor); unfortunately, it's not maintained any more; though there is a fork. A modern alternative (that requires Python though) is UltiSnips. There are more, see this list on the Vim Tips Wiki.
There are three things to evaluate: First, the features of the snippet engine itself, second, the quality and breadth of snippets provided by the author or others; third, how easy it is to add new snippets.
There are two approaches that solves your goal:
abbreviations
and snippets engines
Abbreviations and the old way of doing things. You just type if and space, and tada! You'll find plenty examples around the web. Only a few will be context-sensitive (i.e. they won't expand within comment or string contexts), or able to take the current project spacing style into consideration. In lh-cpp, you'll find the usual control-statement abbreviations for C and C++, they'll need to be duplicated for similar languages (a runtime ftplugin/c/c_snippets.vim from a php ftplugin should do it in your case)-- in lh-misc I support a couple of others languages (for VimL and shell)
Snippet engines are the trendy way of doing the same thing. This time, you will be able to type i or if and then <tab> (or CTRL+SPACE, or ...). Control-statement snippets won't need to be aware of the current context as we need to explicitly require the expansion. Others have already given links to the trendy snippets engines. Snippets from lh-cpp (which relies on mu-template) take the project style into account when expanding control-statement snippets (i.e. some projects want ) and { on a same line, other want a newline in between, ...)
Here's my answer in case you want to go with vanilla Vim.
In the majority of the cases I guess there is no point in entering the parentheses first and filling in the condition later, just type it all in right away:
if (a == 'e')
Then you can either continue
by typing {}<ESC>:
if (a == 'e') {}
^ cursor is here
The cursor is already placed so you can continue with i<CR> and type the body (if properly configured, Vim should indent for you).
or by typing {<CR>}<ESC>:
if (a == 'e') {
}
^ cursor is here
Then you can enter the body by pressing O (open new line above cursor). Possibly Vim also automatically indents here (it doesn't in my configuration).
If you really want to fill in the condition after you have entered this:
if () {
}
^ cursor
you can do so by typing kf(a.
If anybody knows better ways to do this without plugins, suggestions are welcome.

How to script in Vim to yank only lines from a visual selection (or fold) that match a certain pattern?

I'd like to add a command to my .vimrc that allows to, within a visual selection or the range of the current fold level to
yank all, but only those lines that match a certain pattern.
and as a bonus to
reverse their order
and
perform a small pattern substitution.
Specifically the idea is to reduce the legwork in writing the common C idiom fail-goto-rollback, i.e. (can be found in lot of C projects most prominently the Linux kernel) if the body of a function (or a block) is this
someErrorType errorcode;
if(fail1) {
errorcode = someError1;
goto error_1;
}
prepare_a();
if(fail2) {
errorcode = someError2;
goto error_2;
}
then the result of the desired transformation shall be this.
error_2:
/* <insert cleanup code operation that did not fail1 here> */
error_1:
for the "yanking all", you can do:
normal mode: qaq to clear reg a
do visual selection
press :, vim will auto add '<,'>, then g/pattern/y A<Enter>
all your needed lines are in reg a, you can "ap to paste. for the reversing order requirement, I don't understand. What output do you expect. A concrete before/after example may help.
For adding boilerplate code, the usual solution is via a snippets plugin, which solves this (at least partially) in a generic way, instead of building a (possibly brittle) special solution with Vim built-ins.
snippets are like the built-in :abbreviate on steroids, usually with parameter insertions, mirroring, and multiple stops inside them. One of the first, very famous (and still widely used) Vim plugins is snipMate (inspired by the TextMate editor); unfortunately, it's not maintained any more; though there is a fork. A modern alternative (that requires Python though) is UltiSnips. There are more, see this list on the Vim Tips Wiki.
There are three things to evaluate: First, the features of the snippet engine itself, second, the quality and breadth of snippets provided by the author or others; third, how easy it is to add new snippets.

Vim: Use tabs for indentation, spaces for alignment with C source files

Does anybody have her vim setup in a way that uses hard tabs as indentation characters, but does use spaces for alignment? The problem I have is that when starting a continuation line like in
if (condition1 && (anotherlongcondition || /* <-- Here I insert a newline */
|-------|------- whatever /* some additional alignment added automatically */
, then cin (which is a must for me) adds some alignment just the way I prefer positionally, but this alignment is created using as much hard tabs as possible and filling the rest with spaces (as I tried to visualize).
So, in short, cin doesn't really seem to distinguish between indentation and alignment. I'd really like that all the added alignment in the example above is spaces. This way the alignment would be preserved correctly when switching ts temporarily.
To make it clear again, I'd like to be able to write the following code, never pressing <TAB> or <SPACE> in front of the first non-blank character in any line (and not doing any manual shifting or whatever):
void foo(int bar)
{
|-------somestatement;
|-------if (somecondition && (someothercondition ||
|------- whatevercomesnext))
|-------|-------dosomething;
}
I have already tried out ctab.vim, but it focuses on editing an aligned line with soft tabs, which seems silly to me because manual alignment is a task which affords 1-step refinement and not tab-width-step refinement. I did not change the way cin uses mixed tabs and spaces for alignment.
I have not managed to find any built-in way to accomplish that. Perhaps still, there is one? Anyway, I doubt that there's a plugin that does that. Although I admittedly don't vim-script myself and may not have enough experience, I must say that most plugins I tried out only messed up my editor configuration...
In addition to your :set cino=(1, you may also be interested in the 'preserveindent' and 'copyindent' options if you've not encountered them already. They don't completely solve your problem, but they do go some way towards helping.
Okay, sorry for the question. I've finally found some good material for it.
http://vim.1045645.n5.nabble.com/Indent-with-tabs-align-with-spaces-td1183279.html
To sum up, currently vim is not flexible enough for this to be done comfortably.
My workaround currently is using :set cinoptions=(1 which adds only one alignment unit when starting a continuation line. This way, I can be sure that the added alignment is a space (as long as I did not :set ts=1, at least) and add the nice amount of spaces manually. This is still ok in terms of speed and seems to be the least distracting behaviour to me!

Context sensitive word wrap in vi/vim

How can I can specific word wrapping for specific tags. For example, in LaTex I want word wrapping for my paragraphs but not for my figure commands (they are always very long and run off the screen).
Or with Javascript, I want the right margin for code to be at, for example 50 columns, but for the comments to be at only 40 columns
This is not builtin
You could probably script something yourself using a devious combination of `formatexpr` and synID(). I suggest you look at the help of the latter first, because it contains inspirational samples:
for id in synstack(line("."), col("."))
echo synIDattr(id, "name")
endfor
taken from :he synstack
The formatexpr is usually set to something like
:set formatexpr=mylang#Format()
thus delegating to a filetype plugin. You could implement the function to use different margins for different syntax contexts.
Bear in mind
the default formatexpr (if absent, formatprg) are probably no good for a source file (in my experience it has the tendency to string together lines as if they were text paragraphs). But then again, you can implement it any which way you want
that syntax highlighting may become out of sync. I'm not sure what happens when the cursor is at, say, 70% of a large document and you issue ggVGgq. It might not update the syntax highlighting all the way (meaning that your formatexpr function would get the 'wrong' synID() values. You get around this by saying something like
:syntax sync fromstart
this again might impact the highlighting performance depending on the size/complexity of the source and highlighting scripts

Is it possible to format C++ code with VIM?

I am rather new to VIM. I got some source code and this is a mess. At a first sight I would like at least to get a clear and organised view of the code, so I like to get it rightly formatted, I mean indented depending on the depth of the functions and so.
I wonder if it can be done with VIM, and otherwise which other commandline tools for that can you recommend.
Thanks
While vim is a true Swiss-knife I still prefer external tools for some jobs. This approach is some times much more intuitive and easy to remember than using the built-in equivalent.
In the case of indenting, I filter the whole file buffer through astyle. The astyle parameters are much easier to grasp in a couple of minutes, especially if you are not a vim guru. Also astyle provides much more flexibility in fine-tuning the output.
First install astyle:# apt-get install astyle
Then inside vim:
:%!astyle (simple case - astyle default mode is C/C++)
or
:%!astyle --mode=c --style=ansi -s2 (ansi C++ style, use two spaces per indent level)
or
:1,40!astyle --mode=c --style=ansi (ansi C++ style, filter only lines 1-40)
you can do the following:
gg=G
I would highly recommend clang-format nowadays. It allows simple integration of clang-format into Vim, once you have clang-format installed:
http://clang.llvm.org/docs/ClangFormat.html#vim-integration
It is the only code beautifier that really understands your C++ code, and it is really intelligent to beautify the code more like a human being than a machine. E.g.:
void TestFunction(int argument1, int argument2,
int argument3);
void TestFunctionVeryLongName(int argument1,
int argument2,
int argument3);
void TestFunctionWithRidiculouslyLongName(
int argument1, int argument2, int argument3);
Vim will definitely do this, although the results may not be perfect:
First, select the entire file in visual mode: ggVG
Then hit = to reindent everything.
You can learn more about the equal command with: :help =
There is also a Vim plugin relying on clang-format: vim-clang-format
Then you can simply map the formatting command to whatever suits you.
There is a vim plugin that enables formatting on your code from within vim. It's called vim-autoformat and you can download it here:
https://github.com/vim-autoformat/vim-autoformat
It integrates external code-formatting programs into vim. For example, if you want to format C, C++, C# or Java code, you need to install the program astyle, and vim sets it as the format program automatically.
I don't write C++ code, but I write some Java code.
Instead, Vim supports the formatting of some common languages.
I have set up a short cut for me to format the whole code in the buffer.
It will return to the line I just edited :)
" format the file
map <leader>fm gg=G'.
A generic solution along the lines of m000's idea is to use UniversalIndentGUI as an external tool.
Just had to solve this exact problem, so I thought I'd contribute to save others some time.
You can use gg=G to indent your code. But things get hard to understand the moment you want to tweak how that auto-indenting happens. Therefore, if you only care that errant whitespace is removed and don't really care about formatting style, gg=G is the quickest way to go about it, because its built-in.
If you do want to control the style (for example, you're trying to make your code conform to a style guide), then you're going to need an external tool to process your file. You can invoke that tool from within vim with: :%!<toolname> <options>. This pipes the file through the tool and re-loads the processed result. (You can obviously use this for anything else you want to do to your file too)
So the next question is, what external tool should you choose? Regardless, the method is the same:
Install the tool of choice
Make sure its in your path
Add a line to your vimrc file that creates a shortcut key to use so you save time
Use it.
Now, which tool you use depends on the style you're trying to replicate. If you're trying to replicate a widely used style, then chances are astyle is all you need.
If you're trying to replicate a custom style, then you will need two things:
UniversalIndentGui - a front end that lets you play around with various options and live-preview their effect on the source file
A set of source code formatting tools installed and in your path
Between uncrustify and greatcode, you should be able to completely replicate the style you want.
Actually, I lied. There is another way and its called clang-format. However, you're going to want to read the documentation on it and its still in early stages so some options don't work very well. It is a beautiful tool though (definitely the smartest of the lot because constructs an AST of your code) and it is even available for Windows.
If you're going to take the time to read the manual, you also want to check out GNU Indent.
Of course, there is the last way, which is actually taking the time to learn vim's indent rules and writing one for your style. It will take time, but it will work with gg=G.
Some notes on astyle vs uncrustify vs greatcode:
Astyle is good for general formatting, but can't do things like align the declaration of variables and re-style comments very well.
Uncrustify can do a LOT of stuff that astyle can't, but be prepared to spend an hour playing around until you've found the correct combination of options you need. (Or if you feel like wasting a lot of time, use genetic algorithms to figure out the best combination of options for your style and when you do share the code and give me a link so I can use it too :) )
Note that you don't have to choose one tool. With vim, you can map one keystroke to execute several commands in succession, so theoretically you could use a combination of these tools to get exactly what you're looking for.
Last but not least, here's an excerpt from my .vimrc file, where I have mapped F12 to invoke astyle with some options:
"A2 = attached brackets
"-s8 indent 8 spaces
"-xc attached braces to class declarations
"-xj remove braces for single statement ifs and elses
"-c convert tabs to spaces in the non-indentation part of the line
map <F12> :%!astyle -A2 -s8 -xc -xj -c<CR>
Don't judge me on the style. Just use the tool to reproduce what you want.

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