Allow more complex parameters

README.md

@@ -35,6 +35,23 @@ Show commit log of current file:
 :Tig!
 ```
 
+Show blame view of current file:
+```
+:Tig! blame
+```
+
+You can also manually craft tig commands by using variable expansion:
+
+* `%` will expand to the current file path
+* `+` will expand to the current line number (prefixed with `+` so that tig
+  will jump to that line)
+
+```
+:Tig! blame +
+:Tig blame + -- %
+```
+(These two actually result in the same tig command line being executed.)
+
 Configuration
 -------------
 Tig executable: `let g:tig_executable = 'tig'`

plugin/tig.vim

@@ -31,14 +31,22 @@ if has('nvim')
       call termopen(g:tig_executable . ' ' . a:arg, s:callback)
     endfunction
 
-    exec g:tig_open_command
+    let arg = ''
+    if a:0 > 0
+      let args = a:1
+      let args = substitute(args, '%', current, '')
+      let args = substitute(args, '+', '+' . line('.'), '')
+      let arg .= ' ' . args
+    endif
     if a:bang > 0
-      call s:tigopen(current)
-    elseif a:0 > 0
-      call s:tigopen(a:1)
-    else
-      call s:tigopen(g:tig_default_command)
+      let arg .= ' -- ' . current
+    endif
+    if len(arg) == 0
+      let arg = g:tig_default_command
     endif
+
+    exec g:tig_open_command
+    call s:tigopen(arg)
     setlocal nonumber
     setlocal norelativenumber
     setlocal signcolumn=no