xprint.rb

Gem that allows for pretty printing data over multiple lines and with indentation, but unlike the common methods for printing will also work for any object.

xprint will:

• Show basic kinds of data (numbers, strings, symbols, regexps, booleans, nil) pretty much as-is.
  • Also supports commonly used data objects like:
    • Proc, Date, Time, DateTime, BigDecimal, and Rational.
• Show structured data (Arrays/Hashes/Objects) over multiple lines with everything indented consistently.
  • Arrays show a list of all items, also showing the index for each item.
  • Hashes show all key => value pairs, with all =>'s aligned to allow for consistently being able to see where the value starts.
  • Objects show all attributes in the format @var = value, where all the ='s are aligned like with Hashes.
    • Structs are also covered, being slightly different but are shown the same way.
    • Modules are also covered.
• Any nested data, like an object inside of an object, will be shown fully.

The name is short for "X-panding Print".

• Installation
• Usage
• Customization

gem install xprint --platform=ruby

gem install xprint

With Bundler, you can add xprint to your Gemfile:

gem xprint

And then install via bundle install

xprint is very easy to use, as all you have to do is use the xp function:

require 'xprint'

data = {
    people: [
        {
            name: 'Jim',
            age: 19,
            hobbies: ['Video Games']
        },
        {
            name: 'Jam',
            age: 34,
            hobbies: ['Eating Jam']
        }
    ]
}

xp data

Output:

{
  :people => [
    {
      :name    => "Jim", 
      :age     => 19, 
      :hobbies => [
        [0] "Video Games"
      ]
    }, 
    {
      :name    => "Jam", 
      :age     => 34, 
      :hobbies => [
        [0] "Eating Jam"
      ]
    }
  ]
}

Unlike some pretty printing libraries, xprint automatically works with arbitrary objects to see their instance variables:

class Person
    attr_accessor :name, :age, :hobbies

    def initialize(name, age, *hobbies)
        @name    = name
        @age     = age
        @hobbies = hobbies
    end
end

jim = Person.new 'Jim', 19, 'Video Games'
jam = Person.new 'Jam', 34, 'Eating Jam'

data = { people: [jim, jam] }

xp data

Output:

{
  :people => [
    Person(
      @name    = "Jim"
      @age     = 19
      @hobbies = [
        [0] "Video Games"
      ]
    ), 
    Person(
      @name    = "Jam"
      @age     = 34
      @hobbies = [
        [0] "Eating Jam"
      ]
    )
  ]
}

It also works with Structs, which are slightly different than standard objects:

Person = Struct.new(:name, :age, :hobby)
xp Person.new 'Jim', 19, 'Video Games'

Output:

Struct Person(
  name  = "Jim"
  age   = 19
  hobby = "Video Games"
)

If you want to get the text for some data in the same format xp uses, you can use the xpand function.

This allows you to use the expanded data text inside other text, like so:

# We'll be using the same Person class from the previous example.
jim = Person.new 'Jim', 19, 'Video Games'
jam = Person.new 'Jam', 34, 'Eating Jam'

data = [jim, jam]
puts "people: #{xpand data}"

Ouput:

people: [
  Person(
    @name    = "Jim"
    @age     = 19
    @hobbies = [
      [0] "Video Games"
    ]
  ), 
  Person(
    @name    = "Jam"
    @age     = 34
    @hobbies = [
      [0] "Eating Jam"
    ]
  )
]

Note that if you don't want to use the functions from the global namespace, you can call the same function via XPrint::xp or XPrint::xpand.

You can customize some general details about how xprint functions, such as if it prints out colored text (if you're using a terminal that supports colors) and the text to use for each "tab" used when indenting data.

To customize these features, you just modify the XPrint module:

# Want simple looking output and 4-space tabs? Do this:
XPrint.set tab: ' ' * 4,  braces: false, commas: false

friends = {
    'Jim' => {
        favorite_numbers: [1, 2, 3]
    },
    'Jam' => {
        favorite_numbers: [2, 6]
    }
}
xp friends

Output:

"Jim" => 
    :favorite_numbers => 
        [0] 1 
        [1] 2 
        [2] 3
"Jam" => 
    :favorite_numbers => 
        [0] 2
        [1] 6

Check out this wiki page for more in-depth details about customizing xprint, such as how to put your settings into a file and load the settings in your code.