[GR-19220] Implement and untag Enumerable#filter_map (#2152)

PullRequest: truffleruby/2154

Author: eregon

CHANGELOG.md

@@ -13,6 +13,7 @@ Compatibility:
 
 * Implement `String#undump` (#2131, @kustosz)
 * `Errno` constants with the same `errno` number are now the same class.
+* Implement `Enumerable#tally` and `Enumerable#filter_map` (#2144 and #2152, @LillianZ).
 
 Performance:
 

spec/tags/core/enumerable/filter_map_tags.txt

@@ -927,6 +927,19 @@ def reject
     ary
   end
 
+  def filter_map
+    return to_enum(:filter_map) { enumerator_size } unless block_given?
+
+    ary = []
+    each do
+      o = Primitive.single_block_arg
+      v = yield(o)
+      ary << v if v
+    end
+
+    ary
+  end
+
   def reverse_each(&block)
     return to_enum(:reverse_each) { enumerator_size } unless block_given?