Class: PP (Ruby 2.2.2)
Description: Class : PP - Ruby 2.2.2

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Support for the Ruby 2.2 series has ended. See here for reference.

### Home Classes Methods

### In Files

- pp.rb

### Parent

PrettyPrint

### Namespace

- MODULE PP::PPMethods

### Methods

- ::pp
- ::singleline_pp

### Included Modules

- PP::PPMethods

### Class/Module Index

Quicksearch

- Kernel
- PP
- PP::PPMethods

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# PP

A pretty-printer for Ruby objects.

All examples assume you have loaded the PP class with:

    require 'pp'

## What PP Does¶ ↑

Standard output by p returns this:

    #<PP:0x81fedf0 @genspace=#<Proc:0x81feda0>, @group_queue=#<PrettyPrint::GroupQueue:0x81fed3c @queue=[[#<PrettyPrint::Group:0x81fed78 @breakables=[], @depth=0, @break=false>], []]>, @buffer=[], @newline="\n", @group_stack=[#<PrettyPrint::Group:0x81fed78 @breakables=[], @depth=0, @break=false>], @buffer_width=0, @indent=0, @maxwidth=79, @output_width=2, @output=#<IO:0x8114ee4>>

Pretty-printed output returns this:

    #<PP:0x81fedf0
     @buffer=[],
     @buffer_width=0,
     @genspace=#<Proc:0x81feda0>,
     @group_queue=
      #<PrettyPrint::GroupQueue:0x81fed3c
       @queue=
        [[#<PrettyPrint::Group:0x81fed78 @break=false, @breakables=[], @depth=0>],
         []]>,
     @group_stack=
      [#<PrettyPrint::Group:0x81fed78 @break=false, @breakables=[], @depth=0>],
     @indent=0,
     @maxwidth=79,
     @newline="\n",
     @output=#<IO:0x8114ee4>,
     @output_width=2>

## Usage¶ ↑

    pp(obj)             #=> obj
    pp obj              #=> obj
    pp(obj1, obj2, ...) #=> [obj1, obj2, ...]
    pp()                #=> nil

Output `obj(s)` to `$>` in pretty printed format.

It returns `obj(s)`.

## Output Customization¶ ↑

To define a customized pretty printing function for your classes, redefine method `#pretty_print(pp)` in the class.

`#pretty_print` takes the `pp` argument, which is an instance of the PP class. The method uses text, breakable, nest, group and pp to print the object.

## Pretty-Print JSON¶ ↑

To pretty-print JSON refer to JSON#pretty_generate.

## Author¶ ↑

Tanaka Akira <akr@fsij.org>

### Attributes

sharing_detection[RW]

Returns the sharing detection flag as a boolean value. It is false by default.

### Public Class Methods

pp(obj, out=$>, width=79) click to toggle source

Outputs `obj` to `out` in pretty printed format of `width` columns in width.

If `out` is omitted, `$>` is assumed. If `width` is omitted, 79 is assumed.

::pp returns `out`.

                   # File pp.rb, line 97
    def PP.pp(obj, out=$>, width=79)
      q = PP.new(out, width)
      q.guard_inspect_key {q.pp obj}
      q.flush
      #$pp = q
      out << "\n"
    end

singleline_pp(obj, out=$>) click to toggle source

Outputs `obj` to `out` like ::pp but with no indent and newline.

::singleline_pp returns `out`.

                   # File pp.rb, line 109
    def PP.singleline_pp(obj, out=$>)
      q = SingleLine.new(out)
      q.guard_inspect_key {q.pp obj}
      q.flush
      out
    end