✨ Add ESearchResult#each

`ESearchResult#each` allows `ESearchResult` to be used for iteration
over UIDs or message sequence numbers, just like `SearchResult`.

Author: nevans

lib/net/imap/esearch_result.rb

@@ -45,7 +45,7 @@ def initialize(tag: nil, uid: nil, data: nil)
       # Note that SearchResult also implements +to_a+, so it can be used without
       # checking if the server returned +SEARCH+ or +ESEARCH+ data.
       #
-      # Related: #to_sequence_set, #all, #partial
+      # Related: #each, #to_sequence_set, #all, #partial
       def to_a; to_sequence_set.numbers end
 
       # :call-seq: to_sequence_set -> SequenceSet or nil
@@ -61,11 +61,28 @@ def to_a; to_sequence_set.numbers end
       # Note that SearchResult also implements +to_sequence_set+, so it can be
       # used without checking if the server returned +SEARCH+ or +ESEARCH+ data.
       #
-      # Related: #to_a, #all, #partial
+      # Related: #each, #to_a, #all, #partial
       def to_sequence_set
         all || partial&.to_sequence_set || SequenceSet.empty
       end
 
+      # When either #all or #partial contains a SequenceSet of message sequence
+      # numbers or UIDs, +each+ yields each integer in the set.
+      #
+      # When both #all and #partial are +nil+, either because the server
+      # returned no results or because +ALL+ and +PARTIAL+ were not included in
+      # the IMAP#search +RETURN+ options, #each does not yield.
+      #
+      # Note that SearchResult also implements +#each+, so it can be used
+      # without checking if the server returned +SEARCH+ or +ESEARCH+ data.
+      #
+      # Related: #to_sequence_set, #to_a, #all, #partial
+      def each(&)
+        return to_enum(__callee__) unless block_given?
+        to_sequence_set.each_number(&)
+        self
+      end
+
       ##
       # attr_reader: tag
       #

test/net/imap/test_esearch_result.rb

@@ -34,6 +34,28 @@ class ESearchResultTest < Test::Unit::TestCase
     assert_equal [1, 5, 6, 7, 8], esearch.to_a
   end
 
+  test "#each" do
+    esearch = ESearchResult.new(nil, true, [])
+    assert_kind_of Enumerator, esearch.each
+    ary = []
+    assert_same esearch, esearch.each { ary << _1 }
+    assert_equal [], ary
+
+    esearch = ESearchResult.new(nil, false, [["ALL", SequenceSet["1,5:8"]]])
+    assert_equal [1, 5, 6, 7, 8], esearch.each.to_a
+    ary = []
+    assert_same esearch, esearch.each { ary << _1 }
+    assert_equal [1, 5, 6, 7, 8], ary
+
+    esearch = ESearchResult.new(nil, false, [
+      ["PARTIAL", ESearchResult::PartialResult[1..5, "1,5:8"]]
+    ])
+    assert_equal [1, 5, 6, 7, 8], esearch.each.to_a
+    ary = []
+    assert_same esearch, esearch.each { ary << _1 }
+    assert_equal [1, 5, 6, 7, 8], ary
+  end
+
   test "#tag" do
     esearch = ESearchResult.new("A0001", false, [["count", 0]])
     assert_equal "A0001", esearch.tag