Add config supybot.reply.format.list.maximumItems to limit the size of format('%L', ...).

src/conf.py

@@ -481,6 +481,29 @@ def timeElapsed(*args, **kwargs):
     return originalTimeElapsed(*args, **kwargs)
 utils.timeElapsed = timeElapsed
 
+registerGroup(supybot.reply.format, 'list')
+registerChannelValue(supybot.reply.format.list, 'maximumItems',
+    registry.NonNegativeInteger(0, _("""Maximum number of items in a list
+    before the end is replaced with 'and others'. Set to 0 to always
+    show the entire list.""")))
+
+originalCommaAndify = utils.str.commaAndify
+def commaAndify(seq, *args, **kwargs):
+    maximum_items = supybot.reply.format.list.maximumItems.getSpecific(
+        channel=dynamic.channel,
+        network=getattr(dynamic.irc, 'network', None))()
+    if maximum_items:
+        seq = list(seq)
+        initial_length = len(seq)
+        if len(seq) > maximum_items:
+            seq = seq[:maximum_items]
+            nb_skipped = initial_length - maximum_items + 1
+            # Even though nb_skipped is always >= 2, some languages require
+            # nItems for proper pluralization.
+            seq[-1] = utils.str.nItems(nb_skipped, _('other'))
+    return originalCommaAndify(seq, *args, **kwargs)
+utils.str.commaAndify = commaAndify
+
 registerGlobalValue(supybot.reply, 'maximumLength',
     registry.Integer(512*256, _("""Determines the absolute maximum length of
     the bot's reply -- no reply will be passed through the bot with a length

test/test_utils.py

@@ -33,6 +33,7 @@ from supybot.test import *
 import sys
 import time
 import pickle
+import supybot.conf as conf
 import supybot.utils as utils
 from supybot.utils.structures import *
 import supybot.utils.minisix as minisix
@@ -357,6 +358,18 @@ class StrTest(SupyTestCase):
         L.append((3,))
         self.assertRaises(TypeError, utils.str.commaAndify, L)
 
+    def testCommaAndifyConfig(self):
+        f = utils.str.commaAndify
+        L = ['foo', 'bar']
+        with conf.supybot.reply.format.list.maximumItems.context(3):
+            self.assertEqual(f(L), 'foo and bar')
+            L.append('baz')
+            self.assertEqual(f(L), 'foo, bar, and baz')
+            L.append('qux')
+            self.assertEqual(f(L), 'foo, bar, and 2 others')
+            L.append('quux')
+            self.assertEqual(f(L), 'foo, bar, and 3 others')
+
     def testUnCommaThe(self):
         f = utils.str.unCommaThe
         self.assertEqual(f('foo bar'), 'foo bar')