Ruby で定義済の定数を確認する。
クラス定義の外(トッ プレベル)で定義された定数は Object に所属することになります。
Object.constants
ということになる。
たとえば、RUBY_XXXXを見つけるには
>> Object.constants.grep(/ruby/i)
[
[ 0] :RubyVM,
[ 1] :RUBY_VERSION,
[ 2] :RUBY_RELEASE_DATE,
[ 3] :RUBY_PLATFORM,
[ 4] :RUBY_PATCHLEVEL,
[ 5] :RUBY_REVISION,
[ 6] :RUBY_DESCRIPTION,
[ 7] :RUBY_COPYRIGHT,
[ 8] :RUBY_ENGINE,
[ 9] :RubyToken,
[10] :RubyLex,
[11] :RUBYGEMS_ACTIVATION_MONITOR
]
>>
などとなる。
ちょっと困ったことに、requireしたモジュールも定数なので・・・たくさんありますね。
>> Object.constants
[
[ 0] :Object,
[ 1] :Module,
[ 2] :Class,
[ 3] :BasicObject,
[ 4] :Kernel,
[ 5] :NilClass,
[ 6] :NIL,
[ 7] :Data,
[ 8] :TrueClass,
[ 9] :TRUE,
[ 10] :FalseClass,
[ 11] :FALSE,
[ 12] :Encoding,
[ 13] :Comparable,
[ 14] :Enumerable,
[ 15] :String,
[ 16] :Symbol,
[ 17] :Exception,
[ 18] :SystemExit,
[ 19] :SignalException,
[ 20] :Interrupt,
[ 21] :StandardError,
[ 22] :TypeError,
[ 23] :ArgumentError,
[ 24] :IndexError,
[ 25] :KeyError,
[ 26] :RangeError,
[ 27] :ScriptError,
[ 28] :SyntaxError,
[ 29] :LoadError,
[ 30] :NotImplementedError,
[ 31] :NameError,
[ 32] :NoMethodError,
[ 33] :RuntimeError,
[ 34] :SecurityError,
[ 35] :NoMemoryError,
[ 36] :EncodingError,
[ 37] :SystemCallError,
[ 38] :Errno,
[ 39] :ZeroDivisionError,
[ 40] :FloatDomainError,
[ 41] :Numeric,
[ 42] :Integer,
[ 43] :Fixnum,
[ 44] :Float,
[ 45] :Bignum,
[ 46] :Array,
[ 47] :Hash,
[ 48] :ENV,
[ 49] :Struct,
[ 50] :RegexpError,
[ 51] :Regexp,
[ 52] :MatchData,
[ 53] :Marshal,
[ 54] :Range,
[ 55] :IOError,
[ 56] :EOFError,
[ 57] :IO,
[ 58] :STDIN,
[ 59] :STDOUT,
[ 60] :STDERR,
[ 61] :ARGF,
[ 62] :FileTest,
[ 63] :File,
[ 64] :Dir,
[ 65] :Time,
[ 66] :Random,
[ 67] :Signal,
[ 68] :Process,
[ 69] :Proc,
[ 70] :LocalJumpError,
[ 71] :SystemStackError,
[ 72] :Method,
[ 73] :UnboundMethod,
[ 74] :Binding,
[ 75] :Math,
[ 76] :GC,
[ 77] :ObjectSpace,
[ 78] :Enumerator,
[ 79] :StopIteration,
[ 80] :RubyVM,
[ 81] :Thread,
[ 82] :TOPLEVEL_BINDING,
[ 83] :ThreadGroup,
[ 84] :Mutex,
[ 85] :ThreadError,
[ 86] :Fiber,
[ 87] :FiberError,
[ 88] :Rational,
[ 89] :Complex,
[ 90] :RUBY_VERSION,
[ 91] :RUBY_RELEASE_DATE,
[ 92] :RUBY_PLATFORM,
[ 93] :RUBY_PATCHLEVEL,
[ 94] :RUBY_REVISION,
[ 95] :RUBY_DESCRIPTION,
[ 96] :RUBY_COPYRIGHT,
[ 97] :RUBY_ENGINE,
[ 98] :TracePoint,
[ 99] :ARGV,
[100] :Gem,
[101] :RbConfig,
[102] :Config,
[103] :CROSS_COMPILING,
[104] :ConditionVariable,
[105] :Queue,
[106] :SizedQueue,
[107] :MonitorMixin,
[108] :Monitor,
[109] :PrettyPrint,
[110] :PP,
[111] :Pry,
[112] :Forwardable,
[113] :SingleForwardable,
[114] :MethodSource,
[115] :Shellwords,
[116] :StringIO,
[117] :CodeRay,
[118] :Slop,
[119] :Delegator,
[120] :SimpleDelegator,
[121] :FileUtils,
[122] :Etc,
[123] :Tempfile,
[124] :Pathname,
[125] :PryDebugger,
[126] :Debugger,
[127] :BasicSocket,
[128] :Socket,
[129] :SocketError,
[130] :IPSocket,
[131] :TCPSocket,
[132] :TCPServer,
[133] :UDPSocket,
[134] :UNIXSocket,
[135] :UNIXServer,
[136] :Addrinfo,
[137] :SCRIPT_LINES__,
[138] :Digest,
[139] :Set,
[140] :SortedSet,
[141] :TraceLineNumbers,
[142] :LineCache,
[143] :Readline,
[144] :Columnize,
[145] :Exception2MessageMapper,
[146] :IRB,
[147] :RubyToken,
[148] :RubyLex,
[149] :Psych,
[150] :StringScanner,
[151] :ScanError,
[152] :Date,
[153] :DateTime,
[154] :YAML,
[155] :Printers,
[156] :MIME,
[157] :JSON,
[158] :OpenStruct,
[159] :Mutex_m,
[160] :CGI,
[161] :Timeout,
[162] :TimeoutError,
[163] :Net,
[164] :URI,
[165] :Zlib,
[166] :OpenSSL,
[167] :Fcntl,
[168] :SecureRandom,
[169] :Nokogiri,
[170] :Racc,
[171] :ParseError,
[172] :WEBrick,
[173] :Mechanize,
[174] :HTTP,
[175] :DomainName,
[176] :UNF,
[177] :IPAddr,
[178] :Base64,
[179] :NKF,
[180] :Kconv,
[181] :Webrobots,
[182] :WebRobots,
[183] :DRb,
[184] :DRbObject,
[185] :DRbUndumped,
[186] :DRbIdConv,
[187] :AwesomePrint,
[188] :RUBYGEMS_ACTIVATION_MONITOR
]
