missing definition

live.lua

@@ -229,6 +229,14 @@ function live.get_binding(name)
   end
 end
 
+function table.find(h, x)
+  for k,v in pairs(h) do
+    if v == x then
+      return k
+    end
+  end
+end
+
 -- Wrapper for Lua's weird evaluation model.
 -- Lua is persnickety about expressions vs statements, so we need to do some
 -- extra work to get the result of an evaluation.