Expose MRuby source as a gem

lib/mruby/source/path.rb

@@ -0,0 +1,9 @@
+require "pathname"
+
+module MRuby
+  module Source
+    def self.path
+      Pathname.new(File.expand_path('../../../../',__FILE__))
+    end
+  end
+end

lib/mruby/source/version.rb

@@ -0,0 +1,13 @@
+require "mruby/source/path"
+
+module MRuby
+  module Source
+    # Reads a constant defined at version.h
+    MRUBY_READ_VERSION_CONSTANT = -> (name) { Source.path.join('include','mruby','version.h').read.match(/^#define #{name} "?(\w+)"?$/)[1] }
+
+    MRUBY_RELEASE_MAJOR = Integer(MRUBY_READ_VERSION_CONSTANT['MRUBY_RELEASE_MAJOR'])
+    MRUBY_RELEASE_MINOR = Integer(MRUBY_READ_VERSION_CONSTANT['MRUBY_RELEASE_MINOR'])
+    MRUBY_RELEASE_TEENY = Integer(MRUBY_READ_VERSION_CONSTANT['MRUBY_RELEASE_TEENY'])
+    MRUBY_VERSION = [MRUBY_RELEASE_MAJOR,MRUBY_RELEASE_MINOR,MRUBY_RELEASE_TEENY].join('.')
+  end
+end