Switch gem API to constants only

lib/mruby/source.rb

@@ -1,2 +1,30 @@
-require "mruby/source/path"
-require "mruby/source/version"
+require "pathname"
+
+module MRuby
+  module Source
+    # MRuby's source root directory
+    ROOT = Pathname.new(File.expand_path('../../../',__FILE__))
+
+    # Reads a constant defined at version.h
+    MRUBY_READ_VERSION_CONSTANT = -> (name) { ROOT.join('include','mruby','version.h').read.match(/^#define #{name} +"?([\w\. ]+)"?$/)[1] }
+
+    MRUBY_RUBY_VERSION = MRUBY_READ_VERSION_CONSTANT['MRUBY_RUBY_VERSION']
+    MRUBY_RUBY_ENGINE = MRUBY_READ_VERSION_CONSTANT['MRUBY_RUBY_ENGINE']
+
+    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('.')
+    MRUBY_RELEASE_NO = (MRUBY_RELEASE_MAJOR * 100 * 100 + MRUBY_RELEASE_MINOR * 100 + MRUBY_RELEASE_TEENY)
+
+    MRUBY_RELEASE_YEAR = Integer(MRUBY_READ_VERSION_CONSTANT['MRUBY_RELEASE_YEAR'])
+    MRUBY_RELEASE_MONTH = Integer(MRUBY_READ_VERSION_CONSTANT['MRUBY_RELEASE_MONTH'])
+    MRUBY_RELEASE_DAY = Integer(MRUBY_READ_VERSION_CONSTANT['MRUBY_RELEASE_DAY'])
+    MRUBY_RELEASE_DATE = [MRUBY_RELEASE_YEAR,MRUBY_RELEASE_MONTH,MRUBY_RELEASE_DAY].join('.')
+
+    MRUBY_BIRTH_YEAR = Integer(MRUBY_READ_VERSION_CONSTANT['MRUBY_BIRTH_YEAR'])
+
+    MRUBY_AUTHOR = MRUBY_READ_VERSION_CONSTANT['MRUBY_AUTHOR']
+  end
+end

mruby-source.gemspec

@@ -1,7 +1,7 @@
 # coding: utf-8
 lib = File.expand_path('../lib', __FILE__)
 $LOAD_PATH.unshift(lib) unless $LOAD_PATH.include?(lib)
-require 'mruby/source/version'
+require 'mruby/source'
 
 Gem::Specification.new do |spec|
   spec.name          = "mruby-source"