3 files changed, 66 insertions, 0 deletions
diff --git a/mrbgems/mruby-hash-ext/mrblib/hash.rb b/mrbgems/mruby-hash-ext/mrblib/hash.rb
index 846cba9ff..73d1fbe6d 100644
--- a/mrbgems/mruby-hash-ext/mrblib/hash.rb
+++ b/mrbgems/mruby-hash-ext/mrblib/hash.rb
@@ -115,6 +115,22 @@ class Hash
   alias update merge!
 
   ##
+  # call-seq:
+  #    hsh.compact     -> new_hsh
+  #
+  # Returns a new hash with the nil values/key pairs removed
+  #
+  #    h = { a: 1, b: false, c: nil }
+  #    h.compact     #=> { a: 1, b: false }
+  #    h             #=> { a: 1, b: false, c: nil }
+  #
+  def compact
+    result = self.dup
+    result.compact!
+    result
+  end
+
+  ##
   #  call-seq:
   #     hsh.fetch(key [, default] )       -> obj
   #     hsh.fetch(key) {| key | block }   -> obj
diff --git a/mrbgems/mruby-hash-ext/src/hash-ext.c b/mrbgems/mruby-hash-ext/src/hash-ext.c
index 61abc080d..53178ffe4 100644
--- a/mrbgems/mruby-hash-ext/src/hash-ext.c
+++ b/mrbgems/mruby-hash-ext/src/hash-ext.c
@@ -36,6 +36,41 @@ hash_values_at(mrb_state *mrb, mrb_value hash)
   return result;
 }
 
+/*
+ * call-seq:
+ *   hsh.compact!    -> hsh
+ *
+ * Removes all nil values from the hash. Returns the hash.
+ *
+ *   h = { a: 1, b: false, c: nil }
+ *   h.compact!     #=> { a: 1, b: false }
+ */
+static mrb_value
+hash_compact_bang(mrb_state *mrb, mrb_value hash)
+{
+  khiter_t k;
+  khash_t(ht) *h = RHASH_TBL(hash);
+  mrb_int n = -1;
+
+  for (k = kh_begin(h); k != kh_end(h); k++) {
+    if (kh_exist(h, k)) {
+      mrb_value val = kh_value(h, k).v;
+      khiter_t k2;
+
+      if (mrb_nil_p(val)) {
+        kh_del(ht, mrb, h, k);
+        n = kh_value(h, k).n;
+        for (k2 = kh_begin(h); k2 != kh_end(h); k2++) {
+          if (!kh_exist(h, k2)) continue;
+          if (kh_value(h, k2).n > n) kh_value(h, k2).n--;
+        }
+      }
+    }
+  }
+  if (n < 0) return mrb_nil_value();
+  return hash;
+}
+
 void
 mrb_mruby_hash_ext_gem_init(mrb_state *mrb)
 {
@@ -43,6 +78,7 @@ mrb_mruby_hash_ext_gem_init(mrb_state *mrb)
 
   h = mrb->hash_class;
   mrb_define_method(mrb, h, "values_at", hash_values_at, MRB_ARGS_ANY());
+  mrb_define_method(mrb, h, "compact!",  hash_compact_bang, MRB_ARGS_NONE());
 }
 
 void
diff --git a/mrbgems/mruby-hash-ext/test/hash.rb b/mrbgems/mruby-hash-ext/test/hash.rb
index 2ae88c307..ca4e346fb 100644
--- a/mrbgems/mruby-hash-ext/test/hash.rb
+++ b/mrbgems/mruby-hash-ext/test/hash.rb
@@ -82,6 +82,20 @@ assert('Hash#values_at') do
   assert_equal keys, h.values_at(*keys)
 end
 
+assert('Hash#compact') do
+  h = { "cat" => "feline", "dog" => nil, "cow" => false }
+
+  assert_equal({ "cat" => "feline", "cow" => false }, h.compact)
+  assert_equal({ "cat" => "feline", "dog" => nil, "cow" => false }, h)
+end
+
+assert('Hash#compact!') do
+  h = { "cat" => "feline", "dog" => nil, "cow" => false }
+
+  h.compact!
+  assert_equal({ "cat" => "feline", "cow" => false }, h)
+end
+
 assert('Hash#fetch') do
   h = { "cat" => "feline", "dog" => "canine", "cow" => "bovine" }
   assert_equal "feline", h.fetch("cat")