File: README — Documentation for fancy

FancyIrb patches your IRB to create a smooth output experience.

Features

Use fancy colors! You can colorize the prompts, irb errors, stderr and stdout
Output evaluation results as Ruby comments (hash rocket)
Filter your output value using procs

Motivation

I really like the irb_rocket gem, which outputs Ruby results using a hash rocket and colorizes errors. Unfortunately, the implementation leads to bugs, because it tries to run the whole command before printing anything to stdout. For this reason, I’ve rewritten and extended it.

This rubygem is compatible with other great irb gems like hirb, interactive_editor, etc.

Usage

require 'fancy_irb'
FancyIrb.start

You can pass an options hash. These are the default values:

default_options = {
  :rocket_mode     => true,   # activate or deactivate #=> rocket output
  :rocket_prompt   => '#=> ', # prompt to use for the rocket
  :result_prompt   => '=> ',  # prompt to use for normal output
  :colorize => {              # colors hash. Set to nil to deactivate colorizing
    :rocket_prompt => [:blue],
    :result_prompt => [:blue],
    :input_prompt  => nil,
    :irb_errors    => [:red],
    :stderr        => [:red, :bright],
    :stdout        => nil,
    :input         => nil,
    :output        => true, # wirb's output colorization
   },
  :result_proc     => default_result_proc,       # how to get the output result (see below)
  :output_procs    => [default_colorizer_proc],  # you can modify/enhance/log your output
  :east_asian_width => false, # set to true if you have double-width characters (slower)
}

Rocket mode

Rocket mode means: Output result as comment if there is enough space left on the terminal line and stdout does not output more than the current terminal height.

Wrong display widths?

When using double-width unicode chars, you should set :east_asian_width to true. It is deactivated because of performance issues.

Customize colors

See paint

Modify your IRB output

You can modify how to get and display the input. The result_proc is a proc which takes the irb context object and should return the value. You can change it with FancyIrb.set_result_proc do (your code) end. After that, each proc in output_procs gets triggered. They take the value and can return a modified one. You can use the FancyIrb.add_output_proc method for adding new output filter procs.

default_result_proc

default_result_proc = proc{ |context|
  if context.inspect?
    context.last_value.inspect
  else
    context.last_value
  end
}

default_colorizer_proc

default_colorizer_proc = proc{ |value|
  FancyIrb.real_lengths[:output] =    value.size
  if defined?(Wirb) && FancyIrb[:colorize, :output]
    Wirb.colorize_result value
  else
    value 
  end
}

FancyIrb on Windows?

You need ansicon and everything will be fine :D

Example configurations

Default

FancyIrb.start

No colorization

FancyIrb.start :colorize => nil

Use awesome_print for inspecting

require 'ap'
FancyIrb.start :rocket_mode   => false,
               :colorize      => { :output => false,
                                   :result_prompt => :yellow },
               :result_proc   => proc{ |context|
                                   context.last_value.awesome_inspect
                                 }

Smileyfy output

FancyIrb.start
FancyIrb.add_output_proc do |value|
  value + ' :)'
end

TODO

Known bugs

Something is wrong with input-newline when colorizing input
Not all input methods are patched properly (to work with the rocket) –> focusing on the often used ones

Features, maybe

Count string lengths without ansi escape sequences (would be more flexible than remembering)
“Always rocket”-mode

Copyright / Credits

Inspired by the irb_rocket gem from genki.

J-_-L