From e2d54fb3f17ac30c91d855c45060ec5518b75ec5 Mon Sep 17 00:00:00 2001
From: Xavier Noria <fxn@hashref.com>
Date: Sun, 20 Feb 2011 10:52:24 +0100
Subject: documents the backported Range#cover?, and related stuff

---
 railties/guides/source/active_support_core_extensions.textile | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

(limited to 'railties/guides/source/active_support_core_extensions.textile')

diff --git a/railties/guides/source/active_support_core_extensions.textile b/railties/guides/source/active_support_core_extensions.textile
index 9da8ecc6fc..535a048b3b 100644
--- a/railties/guides/source/active_support_core_extensions.textile
+++ b/railties/guides/source/active_support_core_extensions.textile
@@ -528,7 +528,7 @@ The default value can be also specified with a block, which is called in the con
 class User
   attr_accessor :name, :surname
   attr_accessor_with_default(:full_name) {
-	[name, surname].compact.join(" ")
+  [name, surname].compact.join(" ")
   }
 end
 
@@ -2713,6 +2713,14 @@ WARNING: The original +Range#include?+ is still the one aliased to +Range#===+.
 
 NOTE: Defined in +active_support/core_ext/range/include_range.rb+.
 
+h4. +cover?+
+
+Ruby 1.9 provides +cover?+, and Active Support defines it for previous versions as an alias for +include?+.
+
+The method +include?+ in Ruby 1.9 is different from the one in 1.8 for non-numeric ranges: instead of being based on comparisons between the value and the range's endpoints, it walks the range with +succ+ looking for value. This works better for ranges with holes, but it has different complexity and may not finish in some other cases.
+
+In Ruby 1.9 the old behavior is still available in the new +cover?+, which Active Support backports for forward compatibility. For example, Rails uses +cover?+ for ranges in +validates_inclusion_of+.
+
 h4. +overlaps?+
 
 The method +Range#overlaps?+ says whether any two given ranges have non-void intersection:
-- 
cgit v1.2.3

