REPLy

REPLy is a shard that provide a term reader for a REPL (Read Eval Print Loop).

Features

It includes the following features:

• Multiline input
• History
• Pasting of large expressions
• Hook for Syntax highlighting
• Hook for Auto formatting
• Hook for Auto indentation
• Hook for Auto completion (Experimental)
• Work on Windows 10

It doesn't support yet:

• History reverse i-search
• Customizable hotkeys
• Unicode characters

NOTE: REPLy was extracted from https://github.com/I3oris/ic, it was first designed to fit exactly the usecase of a crystal interpreter, so don't hesitate to open an issue to make REPLy more generic and suitable for your project if needed.

Installation

1. Add the dependency to your shard.yml:

   dependencies:
     reply:
       github: I3oris/reply
   

2. Run shards install

Usage

Minimal example

require "reply"

reader = Reply::Reader.new
reader.read_loop do |expression|
  # Eval expression here
  puts " => #{expression}"
end

Customize the Interface

require "reply"

class MyReader < Reply::Reader
  def prompt(io : IO, line_number : Int32, color? : Bool) : Nil
    # Display a custom prompt
  end

  def highlight(expression : String) : String
    # Highlight the expression
  end

  def continue?(expression : String) : Bool
    # Return whether the interface should continue on multiline, depending of the expression
  end

  def format(expression : String) : String?
    # Reformat when expression is submitted
  end

  def indentation_level(expression_before_cursor : String) : Int32?
    # Compute the indentation from the expression
  end

  def save_in_history?(expression : String) : Bool
    # Return whether the expression is saved in history
  end

  def auto_complete(name_filter : String, expression : String) : {String, Array(String)}
    # Return the auto-completion result from expression
  end
end

Similar Project

• fancyline
• crystal-readline

Development

Free to pull request!

Contributing

1. Fork it (https://github.com/I3oris/reply/fork)
2. Create your feature branch (git checkout -b my-new-feature)
3. Commit your changes (git commit -am 'Add some feature')
4. Push to the branch (git push origin my-new-feature)
5. Create a new Pull Request

Contributors

• I3oris - creator and maintainer