Review Hash methods: deprecate redundant, keep unique

- Deprecate Hash#update_keys (use transform_keys! or rekey!)
- Deprecate Hash#update_values (use transform_values! or revalue!)
- Deprecate Hash#fetch_nested (use Hash#dig, Ruby 2.3+)
- Keep rekey/revalue as more powerful alternatives to transform_keys/values
- Keep symbolize_keys/stringify_keys (ActiveSupport compatibility)
- Keep all other Hash methods (40 unique utilities)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: trans

HISTORY.md

@@ -90,6 +90,9 @@ Changes:
   * Add `Dir.find` as convenience wrapper around Ruby's `Find.find`.
   * Deprecate `Dir.recurse` / `Dir.ls_r` (use `Dir.find` or `Find.find` instead).
   * Deprecate `Proc#compose` and `Proc#*` (use `Proc#<<` for right-to-left composition, Ruby 2.6+).
+  * Deprecate `Hash#update_keys` (use `Hash#transform_keys!` or `Hash#rekey!`).
+  * Deprecate `Hash#update_values` (use `Hash#transform_values!` or `Hash#revalue!`).
+  * Deprecate `Hash#fetch_nested` (use `Hash#dig`, adopted by Ruby in 2.3).
   * Fix dead requires for removed `kernel/singleton_class` in Proc and Kernel.
   * Remove misplaced `applique/file_helpers` from core (test infrastructure).
   * Drop unused `test_files` directive from gemspec. (PR#301)

lib/core/facets/hash/fetch_nested.rb

@@ -1,18 +1,17 @@
 class Hash
 
-  # Similar to Hash#fetch but supports nested lookup and is `nil` safe.
+  # @deprecated Use Hash#dig instead (built-in since Ruby 2.3).
   #
-  #     {}.fetch_nested('anything','at','all')  #=> nil
+  # Similar to Hash#dig but supports a block for missing keys,
+  # like Hash#fetch does. Ruby's #dig does not support a block.
   #
-  #     h = {'hello'=>{'world'=>42}}
-  #     h.fetch_nested(*['hello','world'])  #=> 42
+  # TODO: Consider proposing block support for Hash#dig to Ruby core.
   #
-  # CREDIT: T. Yamada and Sean Mackesey
-
-  def fetch_nested(*keys)
+  def fetch_nested(*keys, &block)
+    warn "Hash#fetch_nested is deprecated. Use Hash#dig instead.", uplevel: 1
     begin
-      keys.reduce(self){|accum, k| accum.fetch(k)}
-	rescue (RUBY_VERSION<'1.9' ? IndexError : KeyError)
+      keys.reduce(self) { |accum, k| accum.fetch(k) }
+    rescue KeyError
       block_given? ? yield(*keys) : nil
     end
   end

lib/core/facets/hash/update_keys.rb

@@ -1,21 +1,14 @@
 class Hash
 
-  # Iterate over hash updating just the keys.
+  # @deprecated Use Hash#transform_keys! (Ruby 2.5+) or Hash#rekey! instead.
   #
-  #   h = {:a=>1, :b=>2}
-  #   h.update_keys{ |k| "#{k}!" }
-  #   h  #=> { "a!"=>1, "b!"=>2 }
-  #
-  # @author Trans
-  # @author Evgeniy Dolzhenko (bug fix)
-
-  def update_keys #:yield:
+  def update_keys(&block)
+    warn "Hash#update_keys is deprecated. Use Hash#transform_keys! or Hash#rekey! instead.", uplevel: 1
     if block_given?
-      keys.each { |old_key| store(yield(old_key), delete(old_key)) }
+      transform_keys!(&block)
     else
       to_enum(:update_keys)
     end
   end
 
 end
-

lib/core/facets/hash/update_values.rb

@@ -1,20 +1,14 @@
 class Hash
 
-  # Iterate over hash updating just the values.
+  # @deprecated Use Hash#transform_values! (Ruby 2.4+) or Hash#revalue! instead.
   #
-  #   h = {:a=>1, :b=>2}
-  #   h.update_values{ |v| v + 1 }
-  #   h  #=> { :a=>2, :b=>3 }
-  #
-  # CREDIT: Trans
-
-  def update_values #:yield:
+  def update_values(&block)
+    warn "Hash#update_values is deprecated. Use Hash#transform_values! or Hash#revalue! instead.", uplevel: 1
     if block_given?
-      each{ |k,v| store(k, yield(v)) }
+      transform_values!(&block)
     else
       to_enum(:update_values)
     end
   end
 
 end
-