From aee758ce3360c98e2947579a1078400ece65cbad Mon Sep 17 00:00:00 2001
From: Bryan Mulvihill <mulvihill@informz.com>
Date: Fri, 6 Jan 2017 20:55:01 -0500
Subject: [PATCH] Allow block with Hash#delete

---
 spec/std/hash_spec.cr |  9 +++++++++
 src/hash.cr           | 18 +++++++++++++++++-
 2 files changed, 26 insertions(+), 1 deletion(-)

diff --git a/spec/std/hash_spec.cr b/spec/std/hash_spec.cr
index 54b2c3c86439..3ee161d33604 100644
--- a/spec/std/hash_spec.cr
+++ b/spec/std/hash_spec.cr
@@ -257,6 +257,15 @@ describe "Hash" do
       a = {1 => 2}
       a.delete(2).should be_nil
     end
+
+    describe "with block" do
+      it "executes block if key is not found" do
+        found = true
+        a = {1 => 2}
+        a.delete(3) { found = false }
+        found.should be_false
+      end
+    end
   end
 
   describe "size" do
diff --git a/src/hash.cr b/src/hash.cr
index eacf0969ab1d..5e4452c9efed 100644
--- a/src/hash.cr
+++ b/src/hash.cr
@@ -198,7 +198,23 @@ class Hash(K, V)
     yield value
   end
 
-  # Deletes the key-value pair and returns the value.
+  # Deletes the key-value pair and returns the value, else yields *key* with given block.
+  #
+  # ```
+  # h = {"foo" => "bar"}
+  # h.delete("foo") { |key| "#{key} not found" } # => "bar"
+  # h.fetch("foo", nil)                          # => nil
+  # h.delete("baz") { |key| "#{key} not found" } # => "baz not found"
+  # ```
+  def delete(key, &block)
+    if val = delete(key)
+      val
+    else
+      yield key
+    end
+  end
+
+  # Deletes the key-value pair and returns the value, otherwise returns `nil`.
   #
   # ```
   # h = {"foo" => "bar"}