1 files changed, 47 insertions, 1 deletions

diff --git a/guides/source/active_support_core_extensions.md b/guides/source/active_support_core_extensions.md
index 5ed392d43d..2e1a3ee5dc 100644
--- a/guides/source/active_support_core_extensions.md
+++ b/guides/source/active_support_core_extensions.md
@@ -162,7 +162,7 @@ Active Support provides `duplicable?` to programmatically query an object about
 false.duplicable? # => false
 ```
 
-By definition all objects are `duplicable?` except `nil`, `false`, `true`, symbols, numbers, class, and module objects.
+By definition all objects are `duplicable?` except `nil`, `false`, `true`, symbols, numbers, class, module, and method objects.
 
 WARNING: Any class can disallow duplication by removing `dup` and `clone` or raising exceptions from them. Thus only `rescue` can tell whether a given arbitrary object is duplicable. `duplicable?` depends on the hard-coded list above, but it is much faster than `rescue`. Use it only if you know the hard-coded list is enough in your use case.
 
@@ -1310,6 +1310,38 @@ In above examples "dear" gets cut first, but then `:separator` prevents it.
 
 NOTE: Defined in `active_support/core_ext/string/filters.rb`.
 
+### `truncate_words`
+
+The method `truncate_words` returns a copy of its receiver truncated after a given number of words:
+
+```ruby
+"Oh dear! Oh dear! I shall be late!".truncate_words(4)
+# => "Oh dear! Oh dear!..."
+```
+
+Ellipsis can be customized with the `:omission` option:
+
+```ruby
+"Oh dear! Oh dear! I shall be late!".truncate_words(4, omission: '…')
+# => "Oh dear! Oh dear!…"
+```
+
+Pass a `:separator` to truncate the string at a natural break:
+
+```ruby
+"Oh dear! Oh dear! I shall be late!".truncate_words(3, separator: '!')
+# => "Oh dear! Oh dear! I shall be late..."
+```
+
+The option `:separator` can be a regexp:
+
+```ruby
+"Oh dear! Oh dear! I shall be late!".truncate_words(4, separator: /\s/)
+# => "Oh dear! Oh dear!..."
+```
+
+NOTE: Defined in `active_support/core_ext/string/filters.rb`.
+
 ### `inquiry`
 
 The `inquiry` method converts a string into a `StringInquirer` object making equality checks prettier.
@@ -2862,6 +2894,20 @@ Active Record does not accept unknown options when building associations, for ex
 
 NOTE: Defined in `active_support/core_ext/hash/keys.rb`.
 
+### Working with Values
+
+#### `transform_values` && `transform_values!`
+
+The method `transform_values` accepts a block and returns a hash that has applied the block operations to each of the values in the receiver.
+
+```ruby
+{ nil => nil, 1 => 1, :x => :a }.transform_values { |value| value.to_s.upcase }
+# => {nil=>"", 1=>"1", :x=>"A"}
+```
+There's also the bang variant `transform_values!` that applies the block operations to values in the very receiver.
+
+NOTE: Defined in `active_support/core_text/hash/transform_values.rb`.
+
 ### Slicing
 
 Ruby has built-in support for taking slices out of strings and arrays. Active Support extends slicing to hashes: