# class PP

A pretty-printer for Ruby objects.

## 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.pp` returns `out`.

    # File lib/pp.rb, line 71
    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.pp` but with no indent and newline.

`PP.singleline_pp` returns `out`.

    # File lib/pp.rb, line 83
    def PP.singleline_pp(obj, out=$>)
      q = SingleLine.new(out)
      q.guard_inspect_key {q.pp obj}
      q.flush
      out
    end