[commands] Default converters now take in IDs to match against.

discord/ext/commands/converter.py

@@ -68,12 +68,19 @@ class Converter:
     def convert(self):
         raise NotImplementedError('Derived classes need to implement this.')
 
-class MemberConverter(Converter):
+class IDConverter(Converter):
+    def __init__(self, ctx, argument):
+        super().__init__(ctx, argument)
+        self._id_regex = re.compile(r'([0-9]{15,21})$')
+
+    def _get_id_match(self):
+        return self._id_regex.match(self.argument)
+
+class MemberConverter(IDConverter):
     def convert(self):
         message = self.ctx.message
         bot = self.ctx.bot
-
-        match = re.match(r'<@!?([0-9]+)>$', self.argument)
+        match = self._get_id_match() or re.match(r'<@!?([0-9]+)>$', self.argument)
         server = message.server
         result = None
         if match is None:
@@ -96,12 +103,12 @@ class MemberConverter(Converter):
 
 UserConverter = MemberConverter
 
-class ChannelConverter(Converter):
+class ChannelConverter(IDConverter):
     def convert(self):
         message = self.ctx.message
         bot = self.ctx.bot
 
-        match = re.match(r'<#([0-9]+)>$', self.argument)
+        match = self._get_id_match() or re.match(r'<#([0-9]+)>$', self.argument)
         result = None
         server = message.server
         if match is None:
@@ -137,13 +144,13 @@ class ColourConverter(Converter):
                 raise BadArgument('Colour "{}" is invalid.'.format(arg))
             return method()
 
-class RoleConverter(Converter):
+class RoleConverter(IDConverter):
     def convert(self):
         server = self.ctx.message.server
         if not server:
             raise NoPrivateMessage()
 
-        match = re.match(r'<@&([0-9]+)>$', self.argument)
+        match = self._get_id_match() or re.match(r'<@&([0-9]+)>$', self.argument)
         params = dict(id=match.group(1)) if match else dict(name=self.argument)
         result = discord.utils.get(server.roles, **params)
         if result is None:
@@ -163,13 +170,13 @@ class InviteConverter(Converter):
         except Exception as e:
             raise BadArgument('Invite is invalid or expired') from e
 
-class EmojiConverter(Converter):
+class EmojiConverter(IDConverter):
     @asyncio.coroutine
     def convert(self):
         message = self.ctx.message
         bot = self.ctx.bot
 
-        match = re.match(r'<:([a-zA-Z0-9]+):([0-9]+)>$', self.argument)
+        match = self._get_id_match() or re.match(r'<:[a-zA-Z0-9]+:([0-9]+)>$', self.argument)
         result = None
         server = message.server
         if match is None:
@@ -180,7 +187,7 @@ class EmojiConverter(Converter):
             if result is None:
                 result = discord.utils.get(bot.get_all_emojis(), name=self.argument)
         else:
-            emoji_id = match.group(2)
+            emoji_id = match.group(1)
 
             # Try to look up emoji by id.
             if server: