added support for <shift-tab> to go back a tab stop, and cleaned up the code a bit

plugin/snipMate.vim

@@ -1,6 +1,6 @@
 " File:          snipMate.vim
 " Author:        Michael Sanders
-" Version:       0.82
+" Version:       0.83
 " Description:   snipMate.vim implements some of TextMate's snippets features in
 "                Vim. A snippet is a piece of often-typed text that you can
 "                insert into your document using a trigger word followed by a "<tab>".
@@ -138,7 +138,7 @@ fun! TriggerSnippet()
 		call feedkeys("\<tab>") | return ''
 	endif
 
-	if exists('g:snipPos') | return snipMate#jumpTabStop() | endif
+	if exists('g:snipPos') | return snipMate#jumpTabStop(0) | endif
 
 	let word = matchstr(getline('.'), '\S\+\%'.col('.').'c')
 	for scope in [bufnr('%')] + split(&ft, '\.') + ['_']
@@ -147,7 +147,7 @@ fun! TriggerSnippet()
 		" the snippet.
 		if snippet != ''
 			let col = col('.') - len(trigger)
-			sil exe 's/\V'.escape(trigger, '/').'\%#//'
+			sil exe 's/\V'.escape(trigger, '/.').'\%#//'
 			return snipMate#expandSnip(snippet, col)
 		endif
 	endfor
@@ -159,6 +159,23 @@ fun! TriggerSnippet()
 	return "\<tab>"
 endf
 
+fun! BackwardsSnippet()
+	if exists('g:snipPos') | return snipMate#jumpTabStop(1) | endif
+
+	if exists('g:SuperTabMappingForward')
+		if g:SuperTabMappingBackward == "<s-tab>"
+			let SuperTabKey = "\<c-p>"
+		elseif g:SuperTabMappingForward == "<s-tab>"
+			let SuperTabKey = "\<c-n>"
+		endif
+	endif
+	if exists('SuperTabKey')
+		call feedkeys(SuperTabKey)
+		return ''
+	endif
+	return "\<s-tab>"
+endf
+
 " Check if word under cursor is snippet trigger; if it isn't, try checking if
 " the text after non-word characters is (e.g. check for "foo" in "bar.foo")
 fun s:GetSnippet(word, scope)
@@ -174,6 +191,9 @@ fun s:GetSnippet(word, scope)
 			let word = substitute(word, '.\{-}\W', '', '')
 		endif
 	endw
+	if word == '' && a:word != '.' && stridx(a:word, '.') != -1
+		let [word, snippet] = s:GetSnippet('.', a:scope)
+	endif
 	return [word, snippet]
 endf