Array#to_proc

lib/core/facets/array/to_proc.rb

@@ -0,0 +1,36 @@
+class Array
+
+  # Converts an associative array of method names and arguments
+  # to a Proc making chained calls on a given object.
+  #
+  # Examples
+  #
+  #     [:to_i, :next, [:*, 2]].to_proc.call("2")
+  #     # => 6
+  #
+  #     # Create a proc which calls "obj[1].is_a?(String)":
+  #     chain = [[:[], 1], [:is_a?, String]]
+  #     chain.to_proc
+  #
+  #     the_hash = { one: "One", two: "Two", three: 3, four: nil }
+  #     the_hash.select(&chain)
+  #     # => { :one => "One", :two => "Two" }
+  #
+  #     mapping = { "one" => "1", "two" => "2", "" => "0" }
+  #     the_hash.values.map(&[:to_s, :downcase, [:sub, /one|two|$^/, mapping]])
+  #     # => ["1", "2", "3", "0"]
+  #
+  # Returns [Proc]
+  #
+  # :call-seq:
+  #   [].to_proc
+  #   &[:method1, [:method2, *args], [:method3, ...]]
+  #
+
+  def to_proc
+    proc do |*obj|
+      obj = obj.shift if obj.size == 1
+      reduce(obj) { |chain, (mth, *args)| chain.public_send(mth, *args) }
+    end
+  end unless method_defined?(:to_proc)
+end

test/core/array/test_to_proc.rb

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+covers 'facets/array/to_proc.rb'
+
+test_case Array do
+
+  method :to_proc do
+    test do
+      the_hash = { one: "One", two: "Two", three: 3, four: nil }
+      the_hash.select(&[[:[], 1], [:is_a?, String]]).
+        assert == { :one => "One", :two => "Two" }
+      the_hash.values.map(&[:to_s, :downcase, [:sub, /one|two|$^/, { "one" => "1", "two" => "2", "" => "0" }]]).
+        assert == ["1", "2", "3", "0"]
+    end
+
+  end
+
+end
+