Overview

Conducting a code reading of reline.

Preparation

1. Clone reline git@github.com:ruby/reline.git
2. Create a sample code

$LOAD_PATH.unshift(File.expand_path('lib', __dir__))
require "reline"

prompt = 'prompt> '
use_history = true

begin
  while true
    text = Reline.readmultiline(prompt, use_history) do |multiline_input|
      # Accept the input until `end` is entered
      multiline_input.split.last == "end"
    end

    puts 'You entered:'
    puts text
  end
# If you want to exit, type Ctrl-C
rescue Interrupt
  puts '^C'
  exit 0
end

3. Insert binding.irb at any desired point

Code Reading

Conduct code reading based on the sample code.

1. Call of readline

• ruby/reline/blob/master/lib/reline.rb#L251
• ruby/reline/blob/master/lib/reline.rb#L294

2. Processing of readline

• Omitted due to length

3. Output

• ruby/reline/blob/master/lib/reline/line_editor.rb#L1323
  • The input accumulated in the buffer is finally output here