✨ Add SequenceSet#append, to keep unsorted order

Author: nevans

lib/net/imap/sequence_set.rb

@@ -226,6 +226,8 @@ class IMAP
     # - #add?: If the given object is not an element in the set, adds it and
     #   returns +self+; otherwise, returns +nil+.
     # - #merge: Merges multiple elements into the set; returns +self+.
+    # - #append: Adds a given object to the set, appending it to the existing
+    #   string, and returns +self+.
     # - #string=: Assigns a new #string value and replaces #elements to match.
     # - #replace: Replaces the contents of the set with the contents
     #   of a given object.
@@ -660,6 +662,18 @@ def add(object)
       end
       alias << add
 
+      # Adds a range or number to the set and returns +self+.
+      #
+      # Unlike #add, #merge, or #union, the new value is appended to #string.
+      # This may result in a #string which has duplicates or is out-of-order.
+      def append(object)
+        tuple = input_to_tuple object
+        entry = tuple_to_str tuple
+        tuple_add tuple
+        @string = -(string ? "#{@string},#{entry}" : entry)
+        self
+      end
+
       # :call-seq: add?(object) -> self or nil
       #
       # Adds a range or number to the set and returns +self+.  Returns +nil+

test/net/imap/test_sequence_set.rb

@@ -288,6 +288,14 @@ def compare_to_reference_set(nums, set, seqset)
     assert_equal SequenceSet["1:*"], SequenceSet.new("5:*") << (1..4)
   end
 
+  test "#append" do
+    assert_equal "1,5",     SequenceSet.new("1").append("5").string
+    assert_equal "*,1",     SequenceSet.new("*").append(1).string
+    assert_equal "1:6,4:9", SequenceSet.new("1:6").append("4:9").string
+    assert_equal "1:4,5:*", SequenceSet.new("1:4").append(5..).string
+    assert_equal "5:*,1:4", SequenceSet.new("5:*").append(1..4).string
+  end
+
   test "#merge" do
     seqset = -> { SequenceSet.new _1 }
     assert_equal seqset["1,5"],       seqset["1"].merge("5")