ICR - Interactive Crystal

Interactive console for Crystal Programming Language.

• Usage
  • Require local files
• Installation
  • Arch Linux
• How does it work?
• Commands and special locals
• Development
• Contributors

Usage

It's like irb, but for Crystal:

Require local files

You can require local files by relative path (starts with ./):

require "./src/my_cool_lib"

Libs can also be required from the cli

$ icr -r colorize -r ./src/my_cool_lib

Installation

Prerequisites:

• The latest version of crystal (0.20.0).
• Readline (for Debian/Ubuntu install libreadline6-dev package).
• LLVM development files.

Clone the repo:

git clone https://github.com/crystal-community/icr.git

Switch to repo-directory:

cd icr

Build:

make

And create symlink of ./bin/icr in to direcotory that is listed in your $PATH, e.g.:

sudo ln -s $(realpath ./bin/icr) /usr/bin/icr

(it's necessary only for the first time)

As a shard dependency

If you would like to include icr as a dependency, you can add it to your shard.yml

dependencies:
  icr:
    github: crystal-community/icr
    branch: master

Then just run shards install from your project!

Enjoy!

Arch Linux

Arch Linux users can install ICR from AUR.

How does it work?

• Every time you press Enter it adds new instruction, generates new crystal program and executes it.
• The output is split into 2 parts: regular program output (e.g. output from puts 10) and value returned by the last command
• The regular output is saved, and when you type a new instruction, new program is generated. The saved output is subtracted from the new output, and the difference is printed out. It makes an illusion that only new instructions are executed :)

Commands and special locals

• paste - enables paste mode
• quit or exit - exits current interactive console
• __ - holds the result of the last expression. Example:

icr > "5" + "2"
=> "52"
icr > __.to_i - 10
=> 42

Development

To run tests:

make test

Contributors

• greyblake Potapov Sergey - creator, maintainer
• BlaXpirit Oleh Prypin - fixes for Crystal 0.16
• puppetpies Brian Hood - support of records
• jwoertink Jeremy Woertink - support of -r option and number of other contributions