New option: g:signify_skip_filename_pattern

Closes #179.

autoload/sy.vim

@@ -14,12 +14,7 @@ function! sy#start() abort
 
   let sy_path = resolve(expand('%:p'))
 
-  if &diff
+  if s:skip(sy_path)
-        \ || !filereadable(sy_path)
-        \ || (exists('g:signify_skip_filetype') && (has_key(g:signify_skip_filetype, &ft)
-        \                                       || (has_key(g:signify_skip_filetype, 'help')
-        \                                       && &bt == 'help')))
-        \ || (exists('g:signify_skip_filename') && has_key(g:signify_skip_filename, sy_path))
     if exists('b:sy')
       call sy#sign#remove_all_signs(bufnr(''))
       unlet! b:sy b:sy_info
@@ -147,3 +142,31 @@ endfunction
 function! sy#buffer_is_active()
   return exists('b:sy') && b:sy.active
 endfunction
+
+function! s:skip(path)
+  if &diff || !filereadable(a:path)
+    return 1
+  endif
+
+  if exists('g:signify_skip_filetype')
+    if has_key(g:signify_skip_filetype, &filetype)
+      return 1
+    elseif has_key(g:signify_skip_filetype, 'help') && (&buftype == 'help')
+      return 1
+    endif
+  endif
+
+  if exists('g:signify_skip_filename') && has_key(g:signify_skip_filename, a:path)
+    return 1
+  endif
+
+  if exists('g:signify_skip_filename_pattern')
+    for pattern in g:signify_skip_filename_pattern
+      if a:path =~ pattern
+        return 1
+      endif
+    endfor
+  endif
+
+  return 0
+endfunction

doc/signify.txt

@@ -94,6 +94,7 @@ All available options:~
     |g:signify_disable_by_default|
     |g:signify_skip_filetype|
     |g:signify_skip_filename|
+    |g:signify_skip_filename_pattern|
     |g:signify_update_on_bufenter|
     |g:signify_update_on_focusgained|
     |g:signify_line_highlight|
@@ -200,17 +201,23 @@ This loads Sy, but it won't look for changes. You can toggle it anytime via
 :SignifyToggle.
 
 ------------------------------------------------------------------------------
-                                                       *g:signify_skip_filetype*
+                                               *g:signify_skip_filename_pattern*
                                                        *g:signify_skip_filename*
+                                                       *g:signify_skip_filetype*
 >
     let g:signify_skip_filetype = { 'vim': 1, 'c': 1 }
     let g:signify_skip_filename = { '/home/user/.vimrc': 1 }
 <
-Don't activate the plugin for these filetypes and/or filenames.
+Don't activate the plugin for these filetypes and/or filenames. Filenames have
+to be absolute paths.
 
-NOTE: Filenames have to be absolute paths.
+These options must be |Dict|s for faster lookup.
+>
+    let g:signify_skip_filename_pattern = [ 'foo.*bar', 'tmp' ]
+<
+Don't activate the plugin for filenames matching these patterns.
 
-Default: Both are empty.
+Default: <none>
 
 ------------------------------------------------------------------------------
                                                   *g:signify_update_on_bufenter*