Repper
Repper is a regular expression pretty printer and formatter for Ruby.
Installation
gem install repper
, or add it to your Gemfile
.
Usage
repper
can be integrated into the REPL (e.g. IRB) through core extensions for Regexp pretty-printing, integrated into editors to format Regexps, or called manually.
There are also a few customization options.
REPL integration
Via Regexp#inspect (recommended)
require 'repper/core_ext/regexp'
in your ~/.irbrc
or ~/.pryrc
to override Regexp#inspect
and automatically use repper
to display Regexps:
Via Kernel#pp
Alternatively, require 'repper/core_ext/kernel'
to make the pp
command give nicer output for Regexps (which will look like above by default).
Editor integration
Use vscode-repper to format Regexps in VSCode.
Using Repper manually
Repper.call(/foo/) # pretty prints the given Regexp and returns nil
Repper.render(/foo/) # returns the pretty print String
Customization
Customizing the format
Multiple formats are available out of the box:
:annotated
is the default, verbose format, shown above:inline
adds only colorization and does not restructure the Regexp:structured
is like:annotated
, just without annotations:x
(or:extended
) returns a lightly formatted but equivalent Regexp- this format is used for the repper executable and vscode-repper
You can change the format globally:
Repper.format = :structured
Or pick a format on a case-by-case basis:
Or create your own format:
require 'csv'
csv_format = ->(tokens, _theme) { tokens.map(&:text).to_csv }
Repper.render(/re[\p{pe}\r]$/, format: csv_format)
=> "/,re,[,\\p{pe},\\r,],$,/\n"
Customizing the colors
The color theme can also be set globally or passed on call:
Repper.theme = :monokai # a nicer theme, if the terminal supports it
Repper.call(/foo/, theme: nil) # render without colors
Or create your own theme - you can use all colors supported by the rainbow
gem.
Repper.theme = {
group: :green,
set: :red,
default: :white,
}
Contributing
Bug reports and pull requests are welcome on GitHub at https://github.com/jaynetics/repper.
License
The gem is available as open source under the terms of the MIT License.