initial commit

.vim/autoload/xolox/misc/persist.vim

@@ -0,0 +1,50 @@
+" Persist/recall Vim values from/to files.
+"
+" Author: Peter Odding <peter@peterodding.com>
+" Last Change: June 30, 2014
+" URL: http://peterodding.com/code/vim/misc/
+"
+" 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.
+
+function! xolox#misc#persist#load(filename, ...) " {{{1
+  " 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()
+  let default_value = exists('a:1') ? a:1 : 0
+  try
+    let lines = readfile(a:filename)
+    return eval(join(lines, "\n"))
+  catch
+    return default_value
+  endtry
+endfunction
+
+function! xolox#misc#persist#save(filename, value) " {{{1
+  " 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()
+  return xolox#misc#perm#update(a:filename, split(string(a:value), "\n"))
+endfunction
+
+" vim: ts=2 sw=2 et