Empty highlighting for unknown filetypes

pkg/highlight/highlighter.go

@@ -68,6 +68,8 @@ func combineLineMatch(src, dst LineMatch) LineMatch {
 // A State represents the region at the end of a line
 type State *region
 
+var EmptyDef = Def{nil, &rules{}}
+
 // LineStates is an interface for a buffer-like object which can also store the states and matches for every line
 type LineStates interface {
 	LineBytes(n int) []byte