add support for bazaar

README.md

@@ -12,7 +12,7 @@ It's fast, highly configurable and well documented.
 
 Features:
 
-- supports git, mercurial
+- supports git, mercurial, bzr
 - apart from signs there is also optional line highlighting
 - you can toggle the plugin per buffer
 - fully configurable through global variables

doc/signify.txt

@@ -47,6 +47,7 @@ version control system:
 
     - git
     - mercurial
+    - bzr
 
 The plugin defines 3 new kinds of signs and their corresponding highlighting
 classes. It tries to inherent existing colors from the LineNr class, if that

plugin/signify.vim

@@ -115,6 +115,11 @@ endfunction
 
 "  Functions -> s:get_diff()  {{{2
 function! s:get_diff(path) abort
+    if !executable('grep')
+        echoerr "signify: I cannot work without grep!"
+        finish
+    endif
+
     if executable('git')
         let diff = system('git diff --no-ext-diff -U0 '. fnameescape(a:path) .'| grep "^@@ "')
         if !v:shell_error
@@ -129,6 +134,13 @@ function! s:get_diff(path) abort
         endif
     endif
 
+    if executable('bzr') && executable('diff')
+        let diff = system('bzr diff --using diff --diff-options=-U0 '. fnameescape(a:path) .'| grep "^@@ "')
+        if !v:shell_error
+            return diff
+        endif
+    endif
+
     return []
 endfunction
 
@@ -205,7 +217,7 @@ function! s:process_diff(diff) abort
         " Parse diff output.
         let tokens = matchlist(line, '\v^\@\@ -(\d+),?(\d*) \+(\d+),?(\d*)')
         if empty(tokens)
-            echoerr 'signify: Could not parse this line "'. line .'"'
+            echoerr 'signify: I cannot parse this line "'. line .'"'
         endif
 
         let [ old_line, old_count, new_line, new_count ] = [ str2nr(tokens[1]), (tokens[2] == '') ? 1 : str2nr(tokens[2]), str2nr(tokens[3]), (tokens[4] == '') ? 1 : str2nr(tokens[4]) ]