# Miscellaneous auto-load Vim scripts

The vim-misc plug-in contains Vim scripts that are used by most of the [Vim
plug-ins I've written] [plugins] yet don't really belong with any single one of
the plug-ins. Basically it's an extended standard library of Vim script
functions that I wrote during the development of my Vim profile and plug-ins.

In the past these scripts were bundled with each plug-in, however that turned
out to be a maintenance nightmare for me. That's why the miscellaneous scripts
are now a proper plug-in with their own page on Vim Online.

Because the miscellaneous scripts are no longer bundled with my Vim plug-ins,
users are now required to install the miscellaneous scripts separately. This is
unfortunate for users who are upgrading from a previous release that did bundle
the miscellaneous scripts, but I don't see any way around this. Sorry!

## Installation

Please refer to the [installation instructions] [howto-install] on GitHub.

## Function documentation

Below is the documentation for the functions included in the miscellaneous
scripts. Anyone is free to use these functions in their own Vim profile and/or
plug-ins. I care about backwards compatibility so won't break it without a good
reason to do so.

For those who are curious: The function descriptions given below were extracted
from the source code of the miscellaneous scripts using the Python module
`vimdoctool.py` included in [vim-tools] [].

<!-- Start of generated documentation -->

The documentation of the 95 functions below was extracted from
19 Vim scripts on April  1, 2015 at 23:39.

### Asynchronous Vim script evaluation

The `xolox#misc#async#call()` function builds on top of `xolox#misc#os#exec()`
to support asynchronous evaluation of Vim scripts. The first (and for now
only) use case is my [vim-easytags][] plug-in which has a bunch of
conflicting requirements:

1. I want the [vim-easytags][] plug-in to be as portable as possible.
   Ideally everything is implemented in Vim script because that's the only
   thing I can rely on to be available for all potential users of the
   plug-in!

2. Because of point one I've been forced to implement tags file reading,
   parsing, (fold case) sorting and writing in Vim script. This is fine for
   small tags files but once they grow to a couple of megabytes it becomes
   annoying because Vim is unresponsive during tags file updates (key
   presses are fortunately buffered due to Vim's input model but that
   doesn't make it a nice user experience :-).

3. I could (and did in the past) come up with all sorts of hacks to speed
   things up without switching away from Vim script, but none of them are
   going to solve the fundamental problem that Vim's unresponsive hiccups
   become longer as tags files grow larger.

By now it should be clear where this is heading: _Why not handle tags file
updates in a Vim process that runs in the background without blocking the
Vim process that the user is interacting with?_ It turns out that there are
quite a few details to take care of, but with those out of the way, it might
just work! I'm actually hoping to make asynchronous updates the default mode
in [vim-easytags][]. This means I need this functionality to be as
portable and robust as possible.

**Status:** This code has seen little testing so I wouldn't trust it too
much just yet. On the other hand, as I said, my intention is to make this
functionality as portable and robust as possible. You be the judge :-).

[vim-easytags]: http://peterodding.com/code/vim/easytags/

#### The `xolox#misc#async#call()` function

Call a Vim script function asynchronously by starting a hidden Vim process
in the background. Once the function returns the hidden Vim process
terminates itself. This function takes a single argument which is a
dictionary with the following key/value pairs:

 - **function** (required): The name of the Vim function to call inside
   the child process (a string). I suggest using an [autoload][] function
   for this, see below.

 - **arguments** (optional): A list of arguments to pass to the function.
   This list is serialized to a string using [string()][] and deserialized
   using [eval()][].

 - **callback** (optional): The name of a Vim function to call in the
   parent process when the child process has completed (a string).

 - **clientserver** (optional): If this is true (1) the child process will
   notify the parent process when it has finished (the default is true).
   This works using Vim's client/server support which is not always
   available. As a fall back Vim's [CursorHold][] automatic command is
   also supported (although the effect is not quite as instantaneous :-).

This functionality is experimental and non trivial to use, so consider
yourself warned :-).

**Limitations**

I'm making this functionality available in [vim-misc][] because I think it
can be useful to other plug-ins, however if you are going to use it you
should be aware of the following limitations:

 - Because of the use of multiple processes this functionality is only
   suitable for 'heavy' tasks.

 - The function arguments are serialized to a string which is passed to
   the hidden Vim process as a command line argument, so the amount of
   data you can pass will be limited by your operating environment.

 - The hidden Vim process is explicitly isolated from the user in several
   ways (see below for more details). This is to make sure that the hidden
   Vim processes are fast and don't clobber the user's editing sessions in
   any way.

**Changes to how Vim normally works**

You have to be aware that the hidden Vim process is initialized in a
specific way that is very different from your regular Vim editing
sessions:

 - Your [vimrc][] file is ignored using the `-u NONE` command line option.

 - Your [gvimrc][] file (if you even knew it existed ;-) is ignored using
   the `-U NONE` command line option.

 - Plug-in loading is skipped using the `--noplugin` command line option.

 - Swap files (see [swap-file][]) are disabled using the `-n` command line
   option. This makes sure asynchronous Vim processes don't disturb the
   user's editing session.

 - Your [viminfo][] file is ignored using the `-i NONE` command line
   option. Just like with swap files this makes sure asynchronous Vim
   processes don't disturb the user's editing session.

 - No-compatible mode is enabled using the `-N` command line option
   (usually the existence of your vimrc script would have achieved the
   same effect but since we disable loading of your vimrc we need to spell
   things out for Vim).

**Use an auto-load function**

The function you want to call is identified by its name which has to be
defined, but I just explained above that all regular initialization is
disabled for asynchronous Vim processes, so what gives? The answer is to
use an [autoload][] function. This should work fine because the
asynchronous Vim process 'inherits' the value of the ['runtimepath'][]
option from your editing session.

['runtimepath']: http://vimdoc.sourceforge.net/htmldoc/options.html#'runtimepath'
[autoload]: http://vimdoc.sourceforge.net/htmldoc/eval.html#autoload
[CursorHold]: http://vimdoc.sourceforge.net/htmldoc/autocmd.html#CursorHold
[eval()]: http://vimdoc.sourceforge.net/htmldoc/eval.html#eval()
[gvimrc]: http://vimdoc.sourceforge.net/htmldoc/gui.html#gvimrc
[string()]: http://vimdoc.sourceforge.net/htmldoc/eval.html#string()
[swap-file]: http://vimdoc.sourceforge.net/htmldoc/recover.html#swap-file
[vim-misc]: http://peterodding.com/code/vim/misc/
[viminfo]: http://vimdoc.sourceforge.net/htmldoc/starting.html#viminfo
[vimrc]: http://vimdoc.sourceforge.net/htmldoc/starting.html#vimrc

#### The `xolox#misc#async#inside_child()` function

Entry point inside the hidden Vim process that runs in the background.
Invoked indirectly by `xolox#misc#async#call()` because it runs a command
similar to the following:

    vim --cmd 'call xolox#misc#async#inside_child(...)'

This function is responsible for calling the user defined function,
capturing exceptions and reporting the results back to the parent Vim
process using Vim's client/server support or a temporary file.

#### The `xolox#misc#async#callback_to_parent()` function

When Vim was compiled with client/server support this function (in the
parent process) will be called by `xolox#misc#async#inside_child()` (in
the child process) after the user defined function has returned. This
enables more or less instant callbacks after running an asynchronous
function.

#### The `xolox#misc#async#periodic_callback()` function

When client/server support is not being used the vim-misc plug-in
improvises: It uses Vim's [CursorHold][] event to periodically check if an
asynchronous process has written its results to one of the expected
temporary files. If a response is found the temporary file is read and
deleted and then `xolox#misc#async#callback_to_parent()` is called to
process the response.

[CursorHold]: http://vimdoc.sourceforge.net/htmldoc/autocmd.html#CursorHold

### Handling of special buffers

The functions defined here make it easier to deal with special Vim buffers
that contain text generated by a Vim plug-in. For example my [vim-notes
plug-in] [vim-notes] generates several such buffers:

- [:RecentNotes] [RecentNotes] lists recently modified notes
- [:ShowTaggedNotes] [ShowTaggedNotes] lists notes grouped by tags
- etc.

Because the text in these buffers is generated, Vim shouldn't bother with
swap files and it should never prompt the user whether to save changes to
the generated text.

[vim-notes]: http://peterodding.com/code/vim/notes/
[RecentNotes]: http://peterodding.com/code/vim/notes/#recentnotes_command
[ShowTaggedNotes]: http://peterodding.com/code/vim/notes/#showtaggednotes_command

#### The `xolox#misc#buffer#is_empty()` function

Checks if the current buffer is an empty, unchanged buffer which can be
reused. Returns 1 if an empty buffer is found, 0 otherwise.

#### The `xolox#misc#buffer#prepare()` function

Open a special buffer, i.e. a buffer that will hold generated contents,
not directly edited by the user. The buffer can be customized by passing a
dictionary with the following key/value pairs as the first argument:

- **name** (required): The base name of the buffer (i.e. the base name of
  the file loaded in the buffer, even though it isn't really a file and
  nothing is really 'loaded' :-)
- **path** (required): The pathname of the buffer. May be relevant if
  [:lcd] [lcd] or ['autochdir'] [acd] is being used.

[lcd]: http://vimdoc.sourceforge.net/htmldoc/editing.html#:lcd
[acd]: http://vimdoc.sourceforge.net/htmldoc/options.html#'autochdir'

#### The `xolox#misc#buffer#lock()` function

Lock a special buffer so that its contents can no longer be edited.

#### The `xolox#misc#buffer#unlock()` function

Unlock a special buffer so that its content can be updated.

### Tab completion for user defined commands

#### The `xolox#misc#complete#keywords()` function

This function can be used to perform keyword completion for user defined
Vim commands based on the contents of the current buffer. Here's an
example of how you would use it:

    :command -nargs=* -complete=customlist,xolox#misc#complete#keywords MyCmd call s:MyCmd(<f-args>)

### Rate limiting for Vim's CursorHold event

Several of my Vim plug-ins (e.g. [vim-easytags][], [vim-notes][] and
[vim-session][]) use Vim's [CursorHold][] and [CursorHoldI][] events to
perform periodic tasks when the user doesn't press any keys for a couple of
seconds. These events by default fire after four seconds, this is
configurable using Vim's ['updatetime'][] option. The problem that this
script solves is that there are Vim plug-ins which set the ['updatetime'][]
option to unreasonably low values, thereby breaking my Vim plug-ins and
probably a lot of other Vim plug-ins out there. When users complain about
this I can tell them that another Vim plug-in is to blame, but users don't
care for the difference, their Vim is broken! So I implemented a workaround.
This script enables registration of [CursorHold][] event handlers with a
configurable interval (expressed in seconds). The event handlers will be
called no more than once every interval.

['updatetime']: http://vimdoc.sourceforge.net/htmldoc/options.html#'updatetime'
[CursorHold]: http://vimdoc.sourceforge.net/htmldoc/autocmd.html#CursorHold
[CursorHoldI]: http://vimdoc.sourceforge.net/htmldoc/autocmd.html#CursorHoldI
[vim-easytags]: http://peterodding.com/code/vim/easytags/
[vim-notes]: http://peterodding.com/code/vim/notes/
[vim-session]: http://peterodding.com/code/vim/session/

#### The `xolox#misc#cursorhold#register()` function

Register a [CursorHold][] event handler with a custom interval. This
function takes a single argument which is a dictionary with the following
fields:

 - **function** (required): The name of the event handler function (a
   string).

 - **arguments** (optional): A list of arguments to pass to the event
   handler function (defaults to an empty list).

 - **interval** (optional): The number of seconds between calls to the
   event handler (defaults to 4).

#### The `xolox#misc#cursorhold#autocmd()` function

The 'top level event handler' that's called by Vim whenever the
[CursorHold][] or [CursorHoldI][] event fires. It iterates through the
event handlers registered using `xolox#misc#cursorhold#register()` and
calls each event handler at the appropriate interval, keeping track of
the time when each event handler was last run.

### String escaping functions

#### The `xolox#misc#escape#pattern()` function

Takes a single string argument and converts it into a [:substitute]
[subcmd] / [substitute()] [subfun] pattern string that matches the given
string literally.

[subfun]: http://vimdoc.sourceforge.net/htmldoc/eval.html#substitute()
[subcmd]: http://vimdoc.sourceforge.net/htmldoc/change.html#:substitute

#### The `xolox#misc#escape#substitute()` function

Takes a single string argument and converts it into a [:substitute]
[subcmd] / [substitute()] [subfun] replacement string that inserts the
given string literally.

#### The `xolox#misc#escape#shell()` function

Takes a single string argument and converts it into a quoted command line
argument.

I was going to add a long rant here about Vim's ['shellslash' option]
[shellslash], but really, it won't make any difference. Let's just suffice
to say that I have yet to encounter a single person out there who uses
this option for its intended purpose (running a UNIX style shell on
Microsoft Windows).

[shellslash]: http://vimdoc.sourceforge.net/htmldoc/options.html#'shellslash'

### Human friendly string formatting for Vim

#### The `xolox#misc#format#pluralize()` function

Concatenate a counter (the first argument, expected to be an integer) with
a singular or plural label (the second and third arguments, both expected
to be strings).

#### The `xolox#misc#format#timestamp()` function

Format a time stamp (a string containing a formatted floating point
number) into a human friendly format, for example 70 seconds is phrased as
"1 minute and 10 seconds".

### List handling functions

#### The `xolox#misc#list#unique()` function

Remove duplicate values from the given list in-place (preserves order).

#### The `xolox#misc#list#binsert()` function

Performs in-place binary insertion, which depending on your use case can
be more efficient than calling Vim's [sort()] [sort] function after each
insertion (in cases where a single, final sort is not an option). Expects
three arguments:

1. A list
2. A value to insert
3. 1 (true) when case should be ignored, 0 (false) otherwise

[sort]: http://vimdoc.sourceforge.net/htmldoc/eval.html#sort()

### Functions to interact with the user

#### The `xolox#misc#msg#info()` function

Show a formatted informational message to the user.

This function has the same argument handling as Vim's [printf()] []
function with one notable difference: Any arguments which are not numbers
or strings are coerced to strings using Vim's [string()] [] function.

In the case of `xolox#misc#msg#info()`, automatic string coercion simply
makes the function a bit easier to use.

The messages emitted by this function have no highlighting. Previously
these messages were highlighted using the [Title group] [hl-title], but it
was pointed out in [pull request 16] [pr-16] that this group shouldn't be
used for informational messages because it is meant for titles and because
of this some color schemes use colors that stand out quite a bit, causing
the informational messages to look like errors.

[hl-title]: http://vimdoc.sourceforge.net/htmldoc/syntax.html#hl-Title
[pr-16]: https://github.com/xolox/vim-misc/pull/16
[printf()]: http://vimdoc.sourceforge.net/htmldoc/eval.html#printf()
[string()]: http://vimdoc.sourceforge.net/htmldoc/eval.html#string()

#### The `xolox#misc#msg#warn()` function

Show a formatted warning message to the user.

This function has the same argument handling as the
`xolox#misc#msg#info()` function.

#### The `xolox#misc#msg#debug()` function

Show a formatted debugging message to the user, *if the user has enabled
increased verbosity by setting Vim's ['verbose'] [] option to one
(1) or higher*.

This function has the same argument handling as the
`xolox#misc#msg#info()` function.

In the case of `xolox#misc#msg#debug()`, automatic string coercion
provides lazy evaluation in the sense that complex data structures are
only converted to strings when the user has enabled increased verbosity.

['verbose']: http://vimdoc.sourceforge.net/htmldoc/options.html#'verbose'

### Integration between Vim and its environment

#### The `xolox#misc#open#file()` function

Given a pathname or URL as the first argument, this opens the file with
the program associated with the file type. So for example a text file
might open in Vim, an `*.html` file would probably open in your web
browser and a media file would open in a media player.

This should work on Windows, Mac OS X and most Linux distributions. If
this fails to find a file association, you can pass one or more external
commands to try as additional arguments. For example:

    :call xolox#misc#open#file('/path/to/my/file', 'firefox', 'google-chrome')

This generally shouldn't be necessary but it might come in handy now and
then.

#### The `xolox#misc#open#url()` function

Given a URL as the first argument, this opens the URL in your preferred or
best available web browser:

- In GUI environments a graphical web browser will open (or a new tab will
  be created in an existing window)
- In console Vim without a GUI environment, when you have any of `lynx`,
  `links` or `w3m` installed it will launch a command line web browser in
  front of Vim (temporarily suspending Vim)

### Vim and plug-in option handling

#### The `xolox#misc#option#get()` function

Expects one or two arguments: 1. The name of a variable and 2. the default
value if the variable does not exist.

Returns the value of the variable from a buffer local variable, global
variable or the default value, depending on which is defined.

This is used by some of my Vim plug-ins for option handling, so that users
can customize options for specific buffers.

#### The `xolox#misc#option#split()` function

Given a multi-value Vim option like ['runtimepath'] [rtp] this returns a
list of strings. For example:

    :echo xolox#misc#option#split(&runtimepath)
    ['/home/peter/Projects/Vim/misc',
     '/home/peter/Projects/Vim/colorscheme-switcher',
     '/home/peter/Projects/Vim/easytags',
     ...]

[rtp]: http://vimdoc.sourceforge.net/htmldoc/options.html#'runtimepath'

#### The `xolox#misc#option#join()` function

Given a list of strings like the ones returned by
`xolox#misc#option#split()`, this joins the strings together into a
single value that can be used to set a Vim option.

#### The `xolox#misc#option#split_tags()` function

Customized version of `xolox#misc#option#split()` with specialized
handling for Vim's ['tags' option] [tags].

[tags]: http://vimdoc.sourceforge.net/htmldoc/options.html#'tags'

#### The `xolox#misc#option#join_tags()` function

Customized version of `xolox#misc#option#join()` with specialized
handling for Vim's ['tags' option] [tags].

#### The `xolox#misc#option#eval_tags()` function

Evaluate Vim's ['tags' option] [tags] without looking at the file
system, i.e. this will report tags files that don't exist yet. Expects
the value of the ['tags' option] [tags] as the first argument. If the
optional second argument is 1 (true) only the first match is returned,
otherwise (so by default) a list with all matches is returned.

### Operating system interfaces

#### The `xolox#misc#os#is_mac()` function

Returns 1 (true) when on Mac OS X, 0 (false) otherwise. You would expect
this to simply check the Vim feature list, but for some obscure reason the
`/usr/bin/vim` included in Mac OS X (verified on version 10.7.5) returns 0
(false) in response to `has('mac')`, so we check the output of `uname`
to avoid false negatives.

#### The `xolox#misc#os#is_win()` function

Returns 1 (true) when on Microsoft Windows, 0 (false) otherwise.

#### The `xolox#misc#os#find_vim()` function

Returns the program name of Vim as a string. On Windows and UNIX this just
[v:progname] [] as an absolute pathname while on Mac OS X there is
some special magic to find MacVim's executable even though it's usually
not on the executable search path. If you want, you can override the
value returned from this function by setting the global variable
`g:xolox#misc#os#vim_progname`.

By default the choice of console Vim vs graphical Vim is made based on
the value of [v:progname] [], but if you have a preference you can pass
the string `vim` or `gvim` as the first and only argument.

[v:progname]: http://vimdoc.sourceforge.net/htmldoc/eval.html#v:progname

#### The `xolox#misc#os#exec()` function

Execute an external command (hiding the console on Microsoft Windows when
my [vim-shell plug-in] [vim-shell] is installed).

Expects a dictionary with the following key/value pairs as the first
argument:

- **command** (required): The command line to execute
- **async** (optional): set this to 1 (true) to execute the command in the
  background (asynchronously)
- **stdin** (optional): a string or list of strings with the input for the
  external command
- **check** (optional): set this to 0 (false) to disable checking of the
  exit code of the external command (by default an exception will be
  raised when the command fails)

Returns a dictionary with one or more of the following key/value pairs:

- **command** (always available): the generated command line that was used
  to run the external command
- **exit_code** (only in synchronous mode): the exit status of the
  external command (an integer, zero on success)
- **stdout** (only in synchronous mode): the output of the command on the
  standard output stream (a list of strings, one for each line)
- **stderr** (only in synchronous mode): the output of the command on the
  standard error stream (as a list of strings, one for each line)

[vim-shell]: http://peterodding.com/code/vim/shell/

#### The `xolox#misc#os#can_use_dll()` function

If a) we're on Microsoft Windows, b) the vim-shell plug-in is installed
and c) the compiled DLL included in vim-shell works, we can use the
vim-shell plug-in to execute external commands! Returns 1 (true)
if we can use the DLL, 0 (false) otherwise.

### Pathname manipulation functions

#### The `xolox#misc#path#which()` function

Scan the executable search path (`$PATH`) for one or more external
programs. Expects one or more string arguments with program names. Returns
a list with the absolute pathnames of all found programs. Here's an
example:

    :echo xolox#misc#path#which('gvim', 'vim')
    ['/usr/local/bin/gvim',
     '/usr/bin/gvim',
     '/usr/local/bin/vim',
     '/usr/bin/vim']

#### The `xolox#misc#path#split()` function

Split a pathname (the first and only argument) into a list of pathname
components.

On Windows, pathnames starting with two slashes or backslashes are UNC
paths where the leading slashes are significant... In this case we split
like this:

- Input: `'//server/share/directory'`
- Result: `['//server', 'share', 'directory']`

Everything except Windows is treated like UNIX until someone has a better
suggestion :-). In this case we split like this:

- Input: `'/foo/bar/baz'`
- Result: `['/', 'foo', 'bar', 'baz']`

To join a list of pathname components back into a single pathname string,
use the `xolox#misc#path#join()` function.

#### The `xolox#misc#path#join()` function

Join a list of pathname components (the first and only argument) into a
single pathname string. This is the counterpart to the
`xolox#misc#path#split()` function and it expects a list of pathname
components as returned by `xolox#misc#path#split()`.

#### The `xolox#misc#path#directory_separator()` function

Find the preferred directory separator for the platform and settings.

#### The `xolox#misc#path#absolute()` function

Canonicalize and resolve a pathname, *regardless of whether it exists*.
This is intended to support string comparison to determine whether two
pathnames point to the same directory or file.

#### The `xolox#misc#path#relative()` function

Make an absolute pathname (the first argument) relative to a directory
(the second argument).

#### The `xolox#misc#path#merge()` function

Join a directory pathname and filename into a single pathname.

#### The `xolox#misc#path#commonprefix()` function

Find the common prefix of path components in a list of pathnames.

#### The `xolox#misc#path#starts_with()` function

Check whether the first pathname starts with the second pathname (expected
to be a directory). This does not perform a regular string comparison;
first it normalizes both pathnames, then it splits them into their
pathname segments and then it compares the segments.

#### The `xolox#misc#path#encode()` function

Encode a pathname so it can be used as a filename. This uses URL encoding
to encode special characters.

#### The `xolox#misc#path#decode()` function

Decode a pathname previously encoded with `xolox#misc#path#encode()`.

#### The `xolox#misc#path#is_relative()` function

Returns true (1) when the pathname given as the first argument is
relative, false (0) otherwise.

#### The `xolox#misc#path#tempdir()` function

Create a temporary directory and return the pathname of the directory.

### Manipulation of UNIX file permissions

Vim's [writefile()][] function cannot set file permissions for newly created
files and although Vim script has a function to get file permissions (see
[getfperm()][]) there is no equivalent for changing a file's permissions.

This omission breaks the otherwise very useful idiom of updating a file by
writing its new contents to a temporary file and then renaming the temporary
file into place (which is as close as you're going to get to atomically
updating a file's contents on UNIX) because the file's permissions will not
be preserved!

**Here's a practical example:** My [vim-easytags][] plug-in writes tags file
updates to a temporary file and renames the temporary file into place. When
I use `sudo -s` on Ubuntu Linux it preserves my environment variables so my
`~/.vimrc` and the [vim-easytags][] plug-in are still loaded. Now when a
tags file is written the file becomes owned by root (my effective user id in
the `sudo` session). Once I leave the `sudo` session I can no longer update
my tags file because it's now owned by root … ಠ_ಠ

[getfperm()]: http://vimdoc.sourceforge.net/htmldoc/eval.html#getfperm()
[vim-easytags]: http://peterodding.com/code/vim/easytags/
[writefile()]: http://vimdoc.sourceforge.net/htmldoc/eval.html#writefile()

#### The `xolox#misc#perm#update()` function

Atomically update a file's contents while preserving the owner, group and
mode. The first argument is the pathname of the file to update (a string).
The second argument is the list of lines to be written to the file. Writes
the new contents to a temporary file and renames the temporary file into
place, thereby preventing readers from reading a partially written file.
Returns 1 if the file is successfully updated, 0 otherwise.

Note that if `xolox#misc#perm#get()` and `xolox#misc#perm#set()` cannot be
used to preserve the file owner/group/mode the file is still updated using
a rename (for compatibility with non-UNIX systems and incompatible
`/usr/bin/stat` implementations) so in that case you can still lose the
file's owner/group/mode.

#### The `xolox#misc#perm#get()` function

Get the owner, group and permissions of the pathname given as the first
argument. Returns an opaque value which you can later pass to
`xolox#misc#perm#set()`.

#### The `xolox#misc#perm#set()` function

Set the permissions (the second argument) of the pathname given as the
first argument. Expects a permissions value created by
`xolox#misc#perm#get()`.

### Persist/recall Vim values from/to files

Vim's [string()][] function can be used to serialize Vim script values like
numbers, strings, lists, dictionaries and composites of them to a string
which can later be evaluated using the [eval()][] function to turn it back
into the original value. This Vim script provides functions to use these
functions to persist and recall Vim values from/to files. This is very
useful for communication between (possibly concurrent) Vim processes.

#### The `xolox#misc#persist#load()` function

Read a Vim value like a number, string, list or dictionary from a file
using [readfile()][] and [eval()][]. The first argument is the filename of
the file to read (a string). The optional second argument specifies the
default value which is returned when the file can't be loaded. This
function returns the loaded value or the default value (which itself
defaults to the integer 0).

[eval()]: http://vimdoc.sourceforge.net/htmldoc/eval.html#eval()
[readfile()]: http://vimdoc.sourceforge.net/htmldoc/eval.html#readfile()

#### The `xolox#misc#persist#save()` function

Write a Vim value like a number, string, list or dictionary to a file
using [string()][] and [writefile()][]. The first argument is the filename
of the file to write (a string) and the second argument is the value to
write (any value).

This function writes the serialized value to an intermediate file which is
then renamed into place atomically. This avoids issues with concurrent
processes where for example a producer has written a partial file which is
read by a consumer before the file is complete. In this case the consumer
would read a corrupt value. The rename trick avoids this problem.

[string()]: http://vimdoc.sourceforge.net/htmldoc/eval.html#string()
[writefile()]: http://vimdoc.sourceforge.net/htmldoc/eval.html#writefile()

### String handling

#### The `xolox#misc#str#slug()` function

Convert a string to a "slug" - something that can be safely used in
filenames and URLs without worrying about quoting/escaping of special
characters.

#### The `xolox#misc#str#ucfirst()` function

Uppercase the first character in a string (the first argument).

#### The `xolox#misc#str#unescape()` function

Remove back slash escapes from a string (the first argument).

#### The `xolox#misc#str#compact()` function

Compact whitespace in a string (the first argument).

#### The `xolox#misc#str#trim()` function

Trim all whitespace from the start and end of a string (the first
argument).

#### The `xolox#misc#str#indent()` function

Indent all lines in a multi-line string (the first argument) with a
specific number of *space characters* (the second argument, an integer).

#### The `xolox#misc#str#dedent()` function

Remove common whitespace from a multi line string.

### Test runner & infrastructure for Vim plug-ins

The Vim auto-load script `autoload/xolox/misc/test.vim` contains
infrastructure that can be used to run an automated Vim plug-in test suite.
It provides a framework for running test functions, keeping track of the
test status, making assertions and reporting test results to the user.

#### The `xolox#misc#test#reset()` function

Reset counters for executed tests and passed/failed assertions.

#### The `xolox#misc#test#summarize()` function

Print a summary of test results, to be interpreted interactively.

#### The `xolox#misc#test#wrap()` function

Call a function in a try/catch block and prevent exceptions from bubbling.
The name of the function should be passed as the first and only argument;
it should be a string containing the name of a Vim auto-load function.

#### The `xolox#misc#test#passed()` function

Record a test which succeeded.

#### The `xolox#misc#test#failed()` function

Record a test which failed.

#### The `xolox#misc#test#assert_true()` function

Check whether an expression is true.

#### The `xolox#misc#test#assert_equals()` function

Check whether two values are the same.

#### The `xolox#misc#test#assert_same_type()` function

Check whether two values are of the same type.

### Tests for the miscellaneous Vim scripts

The Vim auto-load script `autoload/xolox/misc/tests.vim` contains the
automated test suite of the miscellaneous Vim scripts. Right now the
coverage is not very high yet, but this will improve over time.

#### The `xolox#misc#tests#run()` function

Run the automated test suite of the miscellaneous Vim scripts. To be used
interactively. Intended to be safe to execute irrespective of context.

#### The `xolox#misc#tests#pattern_escaping()` function

Test escaping of regular expression patterns with
`xolox#misc#escape#pattern()`.

#### The `xolox#misc#tests#substitute_escaping()` function

Test escaping of substitution strings with
`xolox#misc#escape#substitute()`.

#### The `xolox#misc#tests#shell_escaping()` function

Test escaping of shell arguments with `xolox#misc#escape#shell()`.

#### The `xolox#misc#tests#making_a_list_unique()` function

Test removing of duplicate values from lists with
`xolox#misc#list#unique()`.

#### The `xolox#misc#tests#binary_insertion()` function

Test the binary insertion algorithm implemented in
`xolox#misc#list#binsert()`.

#### The `xolox#misc#tests#getting_configuration_options()` function

Test getting of scoped plug-in configuration "options" with
`xolox#misc#option#get()`.

#### The `xolox#misc#tests#splitting_of_multi_valued_options()` function

Test splitting of multi-valued Vim options with
`xolox#misc#option#split()`.

#### The `xolox#misc#tests#joining_of_multi_valued_options()` function

Test joining of multi-valued Vim options with `xolox#misc#option#join()`.

#### The `xolox#misc#tests#finding_vim_on_the_search_path()` function

Test looking up Vim's executable on the search path using [v:progname] []
with `xolox#misc#os#find_vim()`.

[v:progname]: http://vimdoc.sourceforge.net/htmldoc/eval.html#v:progname

#### The `xolox#misc#tests#synchronous_command_execution()` function

Test basic functionality of synchronous command execution with
`xolox#misc#os#exec()`.

#### The `xolox#misc#tests#synchronous_command_execution_with_stderr()` function

Test basic functionality of synchronous command execution with
`xolox#misc#os#exec()` including the standard error stream (not available
on Windows when vim-shell is not installed).

#### The `xolox#misc#tests#synchronous_command_execution_with_raising_of_errors()` function

Test raising of errors during synchronous command execution with
`xolox#misc#os#exec()`.

#### The `xolox#misc#tests#synchronous_command_execution_without_raising_errors()` function

Test synchronous command execution without raising of errors with
`xolox#misc#os#exec()`.

#### The `xolox#misc#tests#asynchronous_command_execution()` function

Test the basic functionality of asynchronous command execution with
`xolox#misc#os#exec()`. This runs the external command `mkdir` and tests
that the side effect of creating the directory takes place. This might
seem like a peculiar choice, but it's one of the few 100% portable
commands (Windows + UNIX) that doesn't involve input/output streams.

#### The `xolox#misc#tests#string_case_transformation()` function

Test string case transformation with `xolox#misc#str#ucfirst()`.

#### The `xolox#misc#tests#string_whitespace_compaction()` function

Test compaction of whitespace in strings with `xolox#misc#str#compact()`.

#### The `xolox#misc#tests#string_whitespace_trimming()` function

Test trimming of whitespace in strings with `xolox#misc#str#trim()`.

#### The `xolox#misc#tests#multiline_string_dedent()` function

Test dedenting of multi-line strings with `xolox#misc#str#dedent()`.

#### The `xolox#misc#tests#version_string_parsing()` function

Test parsing of version strings with `xolox#misc#version#parse()`.

#### The `xolox#misc#tests#version_string_comparison()` function

Test comparison of version strings with `xolox#misc#version#at_least()`.

### Timing of long during operations

#### The `xolox#misc#timer#resumable()` function

Create a resumable timer object. This returns an object (a dictionary with
functions) with the following "methods":

 - `start()` instructs the timer object to start counting elapsed time
   (when a timer object is created it is not automatically started).

 - `stop()` instructs the timer object to stop counting elapsed time.
   This adds the time elapsed since `start()` was last called to the
   total elapsed time. This method will raise an error if called out of
   sequence.

 - `format()` takes the total elapsed time and reports it as a string
   containing a formatted floating point number.

Timer objects are meant to accurately time short running operations so
they're dependent on Vim's [reltime()][] and [reltimestr()][] functions.
In order to make it possible to use timer objects in my Vim plug-ins
unconditionally there's a fall back to [localtime()][] when [reltime()][]
is not available. In this mode the timer objects are not very useful but
at least they shouldn't raise errors.

[localtime()]: http://vimdoc.sourceforge.net/htmldoc/eval.html#localtime()
[reltime()]: http://vimdoc.sourceforge.net/htmldoc/eval.html#reltime()
[reltimestr()]: http://vimdoc.sourceforge.net/htmldoc/eval.html#reltimestr()

#### The `xolox#misc#timer#start()` function

Start a timer. This returns a list which can later be passed to
`xolox#misc#timer#stop()`.

#### The `xolox#misc#timer#stop()` function

Show a formatted debugging message to the user, if the user has enabled
increased verbosity by setting Vim's ['verbose'] [verbose] option to one
(1) or higher.

This function has the same argument handling as Vim's [printf()] [printf]
function with one difference: At the point where you want the elapsed time
to be embedded, you write `%s` and you pass the list returned by
`xolox#misc#timer#start()` as an argument.

[verbose]: http://vimdoc.sourceforge.net/htmldoc/options.html#'verbose'
[printf]: http://vimdoc.sourceforge.net/htmldoc/eval.html#printf()

#### The `xolox#misc#timer#force()` function

Show a formatted message to the user. This function has the same argument
handling as Vim's [printf()] [printf] function with one difference: At the
point where you want the elapsed time to be embedded, you write `%s` and
you pass the list returned by `xolox#misc#timer#start()` as an argument.

#### The `xolox#misc#timer#convert()` function

Convert the value returned by `xolox#misc#timer#start()` to a string
representation of the elapsed time since `xolox#misc#timer#start()` was
called. Other values are returned unmodified (this allows using it with
Vim's [map()][] function).

[map()]: http://vimdoc.sourceforge.net/htmldoc/eval.html#map()

### Version string handling

#### The `xolox#misc#version#parse()` function

Convert a version string to a list of integers.

#### The `xolox#misc#version#at_least()` function

Check whether the second version string is equal to or greater than the
first version string. Returns 1 (true) when it is, 0 (false) otherwise.

<!-- End of generated documentation -->

## Contact

If you have questions, bug reports, suggestions, etc. please open an issue or
pull request on [GitHub] []. Download links and documentation can be found on
the plug-in's [homepage] []. If you like the script please vote for it on
[Vim Online] [].

## License

This software is licensed under the [MIT license] [].
© 2015 Peter Odding &lt;<peter@peterodding.com>&gt;.


[GitHub]: http://github.com/xolox/vim-misc
[homepage]: http://peterodding.com/code/vim/misc
[MIT license]: http://en.wikipedia.org/wiki/MIT_License
[plugins]: http://peterodding.com/code/vim/
[Vim Online]: http://www.vim.org/scripts/script.php?script_id=4597
[vim-tools]: http://peterodding.com/code/vim/tools/
[howto-install]: https://github.com/xolox/vim-misc/blob/master/INSTALL.md