DEV.md

Supported features

goruby

• parse program files
• program file arguments
• Flags
  • -0[octal] specify record separator (\0, if no argument)
  • -a autosplit mode with -n or -p (splits $_ into $F)
  • -c check syntax only
  • -Cdirectory cd to directory before executing your script
  • -d set debugging flags (set $DEBUG to true)
  • -e 'command' one line of script. Several -e's allowed. Omit [programfile]
  • -Eex[:in] specify the default external and internal character encodings
  • -Fpattern split() pattern for autosplit (-a)
  • -i[extension] edit ARGV files in place (make backup if extension supplied)
  • -Idirectory specify $LOAD_PATH directory (may be used more than once)
  • -l enable line ending processing
  • -n assume 'while gets(); ... end' loop around your script
  • -p assume loop like -n but print line also like sed
  • -rlibrary require the library before executing your script
  • -s enable some switch parsing for switches after script name
  • -S look for the script using PATH environment variable
  • -T[level=1] turn on tainting checks
  • -v print version number, then turn on verbose mode
  • -w turn warnings on for your script
  • -W[level=2] set warning level; 0=silence, 1=medium, 2=verbose
  • -x[directory] strip off text before #!ruby line and perhaps cd to directory
  • -h show this message, --help for more info

girb

• parse program files
• program file arguments
• Flags
  • -f Suppress read of ~/.irbrc
  • -m Bc mode (load mathn, fraction or matrix are available)
  • -d Set $DEBUG to true (same as `ruby -d')
  • -r load-module Same as `ruby -r'
  • -I path Specify $LOAD_PATH directory
  • -U Same as ruby -U
  • -E enc Same as ruby -E
  • -w Same as ruby -w
  • -W[level=2] Same as ruby -W
  • --context-mode n Set n[0-3] to method to create Binding Object, when new workspace was created
  • --echo Show result(default)
  • --noecho Don't show result
  • --inspect Use `inspect' for output (default except for bc mode)
  • --noinspect Don't use inspect for output
  • --readline Use Readline extension module
  • --noreadline Don't use Readline extension module
  • --prompt prompt-mode/--prompt-mode prompt-mode Switch prompt mode. Pre-defined prompt modes are default', simple', xmp' and inf-ruby'
  • --inf-ruby-mode Use prompt appropriate for inf-ruby-mode on emacs. Suppresses --readline.
  • --sample-book-mode/--simple-prompt Simple prompt mode
  • --noprompt No prompt mode
  • --single-irb Share self with sub-irb.
  • --tracer Display trace for each execution of commands.
  • --back-trace-limit n Display backtrace top n and tail n. The default value is 16.
  • --irb_debug n Set internal debug level to n (not for popular use)
  • --verbose Show details
  • --noverbose Don't show details
  • -v, --version Print the version of irb
  • -h, --help Print help
  • -- Separate options of irb from the list of command-line args

Supported language feature

• everything is an object
  • allow method calls on everything
  • operators are method calls
• full UTF8 support
  • Unicode identifier
  • Unicode symbols
• functions
  • with parens
  • without parens
  • return keyword
  • default values for parameters
  • keyword arguments
  • block arguments
  • hash as last argument without braces
  • splat args (*a)
• function calls
  • with parens
  • without parens
  • with block arguments
• conditionals
  • if
  • if/else
  • if/elif/else
  • ternary ? :
  • unless
  • unless/else
  • case
  • ||
  • &&
• control flow
  • for loop
  • while loop
  • break
    • break unless
    • break if
  • next
  • redo
  • flip flop
• numbers
  • integers
    • integer arithmetics
    • integers 1234
    • integers with underscores 1_234
    • decimal numbers 0d170, 0D170
    • octal numbers 0252, 0o252, 0O252
    • hexadecimal numbers 0xaa, 0xAa, 0xAA, 0Xaa, 0XAa, 0XaA
    • binary numbers 0b10101010, 0B10101010
  • floats
    • float arithmetics
    • 12.34
    • 1234e-2
    • 1.234E1
    • floats with underscores 2.2_22
• booleans
• strings
  • double quoted
  • single quoted
  • character literals (?\n, ?a,...)
  • %q{}
  • %Q{}
  • heredoc
    • without indentation (<<EOF)
    • indented (<<-EOF)
    • “squiggly” heredoc <<~
    • quoted heredoc
      • single quotes <<-'HEREDOC'
      • double quotes <<-"HEREDOC"
      • backticks <<-`HEREDOC`"
  • escaped characters
    • \a bell, ASCII 07h (BEL)
    • \b backspace, ASCII 08h (BS)
    • \t horizontal tab, ASCII 09h (TAB)
    • \n newline (line feed), ASCII 0Ah (LF)
    • \v vertical tab, ASCII 0Bh (VT)
    • \f form feed, ASCII 0Ch (FF)
    • \r carriage return, ASCII 0Dh (CR)
    • \e escape, ASCII 1Bh (ESC)
    • \s space, ASCII 20h (SPC)
    • \\ backslash, \
    • \nnn octal bit pattern, where nnn is 1-3 octal digits ([0-7])
    • \xnn hexadecimal bit pattern, where nn is 1-2 hexadecimal digits ([0-9a-fA-F])
    • \unnnn Unicode character, where nnnn is exactly 4 hexadecimal digits ([0-9a-fA-F])
    • \u{nnnn ...} Unicode character(s), where each nnnn is 1-6 hexadecimal digits ([0-9a-fA-F])
    • \cx or \C-x control character, where x is an ASCII printable character
    • \M-x meta character, where x is an ASCII printable character
    • \M-\C-x meta control character, where x is an ASCII printable character
    • \M-\cx same as above
    • \c\M-x same as above
    • \c? or \C-? delete, ASCII 7Fh (DEL)
  • interpolation #{}
  • automatic concatenation
• arrays
  • array literal [1,2]
  • array indexing arr[2]
  • splat
  • array decomposition
  • implicit array assignment
  • array of strings %w{}
  • array of symbols %i{}
• nil
• hashes
  • literal with => notation (hashrocket)
  • literal with key: notation
  • indexing hash[:foo]
  • every Ruby Object can be a hash key
• symbols
  • :symbol
  • :"symbol"
  • :"symbol" with interpolation
  • :'symbol'
  • %s{symbol}
  • singleton symbols
• regexp
  • /regex/
    • string gsub, e.g. "hello".gsub(/l/,"1")
    • modifiers (implemented but don't do anything atm)
  • %r{regex}
• ranges
  • .. inclusive
  • ... exclusive
• procs
  • Proc.new
  • proc
  • receiving a bloc of code into an argument
  • lambda
  • ->
    • pure, e.g. -> (a, b) {a + b}
    • captures
    • args splat, e.g. -> (*a) { a }
• variables
  • variable assignments
  • globals
• operators
  • +
  • -
  • /
  • *
  • !
  • <
  • >
  • ** (pow)
  • % (modulus)
  • & (AND)
  • ^ (XOR)
  • >> (right shift)
  • << (left shift, append)
  • == (equal)
  • != (not equal)
  • === (case equality)
  • =~ (pattern match)
  • !~ (does not match)
  • <=> (comparison or spaceship operator)
  • <= (less or equal)
  • >= (greater or equal)
  • assignment operators
    • +=
    • -=
    • /=
    • *=
    • %=
    • **=
    • &=
    • |=
    • ^=
    • <<=
    • >>=
    • ||=
    • &&=
• function blocks (procs)
• error handling
  • begin/rescue
  • ensure
  • retry
• constants
• scope operator ::
• classes
  • class objects
  • class Class
  • instance variables
  • class variables
  • class methods
  • instance methods
  • method overrides
  • private
  • protected
  • public
  • inheritance
  • constructors
  • new
  • self
  • singleton classes (also known as the metaclass or eigenclass) class << self
  • assigment methods
  • self defined classes
  • self defined classes with inheritance
• modules
• object main
• comments '#'