From 621487a0cd8acc5bbec73c98ebbb23c519ba6e6d Mon Sep 17 00:00:00 2001
From: takahashim <maki@rubycolor.org>
Date: Mon, 23 Nov 2015 19:51:02 +0900
Subject: add {Array|Hash|String}.try_convert

---
 mrbgems/mruby-hash-ext/mrblib/hash.rb | 19 +++++++++++++++++++
 mrbgems/mruby-hash-ext/test/hash.rb   |  6 ++++++
 2 files changed, 25 insertions(+)

(limited to 'mrbgems/mruby-hash-ext')

diff --git a/mrbgems/mruby-hash-ext/mrblib/hash.rb b/mrbgems/mruby-hash-ext/mrblib/hash.rb
index f72cb54e8..2727e1f65 100644
--- a/mrbgems/mruby-hash-ext/mrblib/hash.rb
+++ b/mrbgems/mruby-hash-ext/mrblib/hash.rb
@@ -60,6 +60,25 @@ class Hash
     h
   end
 
+  ##
+  # call-seq:
+  #     Hash.try_convert(obj) -> hash or nil
+  #
+  # Try to convert <i>obj</i> into a hash, using to_hash method.
+  # Returns converted hash or nil if <i>obj</i> cannot be converted
+  # for any reason.
+  #
+  #     Hash.try_convert({1=>2})   # => {1=>2}
+  #     Hash.try_convert("1=>2")   # => nil
+  #
+  def self.try_convert(obj)
+    if obj.respond_to?(:to_hash)
+      obj.to_hash
+    else
+      nil
+    end
+  end
+
   ##
   # call-seq:
   #     hsh.merge!(other_hash)                                 -> hsh
diff --git a/mrbgems/mruby-hash-ext/test/hash.rb b/mrbgems/mruby-hash-ext/test/hash.rb
index 4a2251b6c..8b6b2e5b9 100644
--- a/mrbgems/mruby-hash-ext/test/hash.rb
+++ b/mrbgems/mruby-hash-ext/test/hash.rb
@@ -39,6 +39,12 @@ assert('Hash.[] "c_key", "c_value"') do
   end
 end
 
+assert('Hash.try_convert') do
+  assert_nil Hash.try_convert(nil)
+  assert_nil Hash.try_convert("{1=>2}")
+  assert_equal({1=>2}, Hash.try_convert({1=>2}))
+end
+
 assert('Hash#merge!') do
   a = { 'abc_key' => 'abc_value', 'cba_key' => 'cba_value' }
   b = { 'cba_key' => 'XXX',  'xyz_key' => 'xyz_value' }
-- 
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