Implement Symbol#casecmp

mrbgems/mruby-symbol-ext/mrblib/symbol.rb

@@ -47,6 +47,17 @@ class Symbol
     self.to_s.upcase.intern
   end
 
+  ##
+  # call-seq:
+  #   sym.casecmp(other)  -> -1, 0, +1 or nil
+  #
+  # Case-insensitive version of <code>Symbol#<=></code>.
+
+  def casecmp(other)
+    return nil unless other.kind_of?(Symbol)
+    self.to_s.upcase <=> other.to_s.upcase
+  end
+
   #
   # call-seq:
   #   sym.empty?   -> true or false

mrbgems/mruby-symbol-ext/test/symbol.rb

@@ -29,6 +29,13 @@ assert("Symbol#upcase") do
   assert_equal :HELLO, :hEllO.upcase
 end
 
+assert("Symbol#casecmp") do
+  assert_equal 0, :HELLO.casecmp(:hEllO)
+  assert_equal 1, :HELLO.casecmp(:hEllN)
+  assert_equal -1, :HELLO.casecmp(:hEllP)
+  assert_nil :HELLO.casecmp("hEllO")
+end
+
 assert("Symbol#empty?") do
   assert_true :''.empty?
 end