Review Enumerable methods: deprecate 7 redundant methods

- Deprecate compact_map (use filter_map, Ruby 2.7+)
- Deprecate defer (use lazy, Ruby 2.0+)
- Deprecate frequency (use tally, Ruby 2.7+)
- Deprecate hinge (use each_with_object)
- Deprecate map_with_index (use map.with_index)
- Deprecate mash (duplicate of graph)
- Deprecate uniq_by (use uniq(&block), Ruby 1.9.2+)
- Keep 27 unique methods including graph, find_yield, per/every,
  squeeze, purge, with_position, cluster, and others

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

Author: trans

HISTORY.md

@@ -93,6 +93,13 @@ Changes:
   * 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).
+  * Deprecate `Enumerable#compact_map` (use `Enumerable#filter_map`, adopted by Ruby in 2.7).
+  * Deprecate `Enumerable#defer` (use `Enumerable#lazy`, adopted by Ruby in 2.0).
+  * Deprecate `Enumerable#frequency` (use `Enumerable#tally`, adopted by Ruby in 2.7).
+  * Deprecate `Enumerable#hinge` (use `Enumerable#each_with_object`, note: block args reversed).
+  * Deprecate `Enumerable#map_with_index` (use `Enumerable#map.with_index`).
+  * Deprecate `Enumerable#mash` (use `Enumerable#graph` instead).
+  * Deprecate `Enumerable#uniq_by` (use `Enumerable#uniq(&block)`, Ruby 1.9.2+).
   * 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/enumerable/compact_map.rb

@@ -15,18 +15,8 @@ module Enumerable
   # does almost the same thing and enum.map{}.compact works too.
 
   def compact_map(&block)
-    y = []
-    if block_given?
-      each do |*a|
-        r = yield(*a)
-        y << r unless r.nil?
-      end
-    else
-      each do |r|
-        y << r unless r.nil?
-      end
-    end
-    y
+    warn "Enumerable#compact_map is deprecated. Use Enumerable#filter_map instead.", uplevel: 1
+    filter_map(&block)
   end
 
   #

lib/core/facets/enumerable/defer.rb

@@ -27,19 +27,8 @@ module Enumerable
   # to output each result and discard it.
   #
   def defer(&blk)
-    if block_given?
-      Denumerator.new do |output|
-        each do |*input|
-          yield(output, *input)
-        end
-      end
-    else
-      Denumerator.new do |output|
-        each do |*input|
-          output.yield(*input)
-        end
-      end
-    end
+    warn "Enumerable#defer is deprecated. Use Enumerable#lazy instead.", uplevel: 1
+    lazy
   end
 
 end

lib/core/facets/enumerable/frequency.rb

@@ -16,8 +16,8 @@ module Enumerable
   #++
 
   def frequency
-    p = Hash.new(0); each{ |v| p[v] += 1 }; p
-
+    warn "Enumerable#frequency is deprecated. Use Enumerable#tally instead.", uplevel: 1
+    tally
   end
 
 end

lib/core/facets/enumerable/hinge.rb

@@ -9,10 +9,9 @@ module Enumerable
   #
   # TODO: Enumerable#hinge will get a new name.
   #
-  def hinge(init={})
-    h = init
-    each{ |v| yield(h,v) }
-    h
+  def hinge(init={}, &block)
+    warn "Enumerable#hinge is deprecated. Use Enumerable#each_with_object instead (note: block args are reversed).", uplevel: 1
+    each_with_object(init) { |e, obj| block.call(obj, e) }
   end
 
 end

lib/core/facets/enumerable/map_with_index.rb

@@ -7,12 +7,9 @@ module Enumerable
   #
   # CREDIT: Gavin Sinclair
 
-  def map_with_index
-    r = []
-    each_with_index do |e, i|
-      r << yield(e, i)
-    end
-    r
+  def map_with_index(&block)
+    warn "Enumerable#map_with_index is deprecated. Use Enumerable#map.with_index instead.", uplevel: 1
+    map.with_index(&block)
   end
 
   # Alias for map_with_index.

lib/core/facets/enumerable/mash.rb

@@ -1,34 +1,11 @@
-module Enumerable
+require 'facets/enumerable/graph'
 
-  # Like `#map`/`#collect`, but generates a Hash. The block is expected
-  # to return two values: the key and the value for the new hash.
-  #
-  #   numbers  = (1..3)
-  #   squares  = numbers.mash{ |n| [n, n*n] }   # { 1=>1, 2=>4, 3=>9 }
-  #   sq_roots = numbers.mash{ |n| [n*n, n] }   # { 1=>1, 4=>2, 9=>3 }
-  #
-  # CREDIT: Andrew Dudzik (adudzik), Trans
+module Enumerable
 
+  # @deprecated Use Enumerable#graph instead.
   def mash(&yld)
-    if yld
-      h = {}
-      each do |*kv|
-        r = yld[*kv]
-        case r
-        when Hash
-          nk, nv = *r.to_a[0]
-        when Range
-          nk, nv = r.first, r.last
-        else
-          nk, nv = *r
-        end
-        h[nk] = nv
-      end
-      h
-    else
-      Enumerator.new(self,:graph)
-    end
+    warn "Enumerable#mash is deprecated. Use Enumerable#graph instead.", uplevel: 1
+    graph(&yld)
   end
 
 end
-

lib/core/facets/enumerable/uniq_by.rb

@@ -1,13 +1,9 @@
 module Enumerable
 
-  # Like #uniq, but determines uniqueness based on a given block.
-  #
-  #   (-5..5).to_a.uniq_by {|i| i*i }
-  #   #=> [-5, -4, -3, -2, -1, 0]
-  #
-  def uniq_by #:yield:
-    h = {}; inject([]) {|a,x| h[yield(x)] ||= a << x}
+  # @deprecated Use Enumerable#uniq with a block instead (Ruby 1.9.2+).
+  def uniq_by(&block)
+    warn "Enumerable#uniq_by is deprecated. Use Enumerable#uniq(&block) instead.", uplevel: 1
+    uniq(&block)
   end
 
 end
-