add method to sort use statements

Fixes #5

README.markdown

@@ -45,6 +45,18 @@ Then, hitting `\e` in normal or insert mode will expand the class name to a full
 $this->getMock('RouterInterface<-- cursor here or on the name; hit \e now to expand the class name'
 ```
 
+### Sort existing use statements alphabetically
+
+If you do not know how to organize use statements, (or anything else, for that
+matter), the alphabetical order might be a sensible choice, because it makes
+finding what you are looking for easier, and reduces the risk for conflicts :
+if everyone adds new things at the same line, conflicts are guaranteed.
+
+This vim plugin defines a `PhpSortUse()` you may use in your mappings:
+
+    autocmd FileType php inoremap <Leader>s <Esc>:call PhpSortUse()<CR>
+    autocmd FileType php noremap <Leader>s :call PhpSortUse()<CR>
+
 ## Installation:
 
 ### Using [pathogen](https://github.com/tpope/vim-pathogen)

plugin/phpns.vim

@@ -156,3 +156,13 @@ function! s:saveCapture(capture)
     let s:capture = a:capture
 endfunction
 
+function! PhpSortUse()
+    let restorepos = line(".") . "normal!" . virtcol(".") . "|"
+     " insert after last use or namespace or <?php
+    if search('^use\_s\_[[:alnum:][:blank:]\\_]*;', 'be') > 0
+        execute "'{,'}-1sort"
+    else
+        throw "No use statements found."
+    endif
+    exe restorepos
+endfunction

tests/test-sort.in

@@ -0,0 +1,17 @@
+
+Sort test 1
+
+STARTTEST
+:%d
+a<?php
+
+use Goo\Baz;
+use Foo\Bar;
+
+class Boo
+{
+}:call PhpSortUse()
+ax:w! test.out
+:qa!
+ENDTEST
+

tests/test-sort.ok

@@ -0,0 +1,8 @@
+<?php
+
+use Foo\Bar;
+use Goo\Baz;
+
+class Boo
+{
+}x