Simplify Connection class

Author: rolandlo

src/vips/Connection.lua

@@ -6,28 +6,18 @@ local vobject = require "vips.vobject"
 
 local vips_lib = ffi.load(ffi.os == "Windows" and "libvips-42.dll" or "vips")
 
-local Connection_method = {}
-
-local Connection = {
-    mt = {
-        __index = Connection_method,
-    }
-}
-
-function Connection.mt:__tostring()
-    return self:filename() or self:nick() or "(nil)"
-end
+local Connection = {}
 
 Connection.new = function(vconnection)
     local connection = {}
     connection.vconnection = vobject.new(vconnection)
     return setmetatable(connection, Connection.mt)
 end
-function Connection_method:vobject()
+function Connection:vobject()
     return ffi.cast(vobject.typeof, self.vconnection)
 end
 
-function Connection_method:filename()
+function Connection:filename()
     -- Get the filename asscoiated with a connection. Return nil if there is no associated file.
     local so = ffi.cast('VipsConnection *', self.vconnection)
     local filename = vips_lib.vips_connection_filename(so)
@@ -38,7 +28,7 @@ function Connection_method:filename()
     end
 end
 
-function Connection_method:nick()
+function Connection:nick()
     -- Make a human-readable name for a connection suitable for error messages.
 
     local so = ffi.cast('VipsConnection *', self.vconnection)
@@ -51,5 +41,8 @@ function Connection_method:nick()
 end
 
 return ffi.metatype("VipsConnection", {
-    __index = Connection
+    __index = Connection,
+    __tostring = function(self)
+        return self:filename() or self:nick() or "(nil)"
+    end
 })