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class PP

Parent:
PrettyPrint
Included modules:
PP::PPMethods

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>

Public Class Methods

pp(obj, out=$>, width=width_for(out)) Show source 
# File lib/pp.rb, line 91
def PP.pp(obj, out=$>, width=width_for(out))
  q = PP.new(out, width)
  q.guard_inspect_key {q.pp obj}
  q.flush
  #$pp = q
  out << "\n"
end

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

If out is omitted, $> is assumed. If width is omitted, the width of out is assumed (see width_for).

PP.pp returns out.

sharing_detection() Show source 
# File lib/pp.rb, line 120
def sharing_detection
  Ractor.current[:pp_sharing_detection]
end

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

sharing_detection=(b) Show source 
# File lib/pp.rb, line 124
def sharing_detection=(b)
  Ractor.current[:pp_sharing_detection] = b
end

Sets the sharing detection flag to b.

singleline_pp(obj, out=$>) Show source 
# File lib/pp.rb, line 103
def PP.singleline_pp(obj, out=$>)
  q = SingleLine.new(out)
  q.guard_inspect_key {q.pp obj}
  q.flush
  out
end

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

PP.singleline_pp returns out.

width_for(out) Show source 
# File lib/pp.rb, line 74
def PP.width_for(out)
  begin
    require 'io/console'
    _, width = out.winsize
  rescue LoadError, NoMethodError, SystemCallError
  end
  (width || ENV['COLUMNS']&.to_i&.nonzero? || 80) - 1
end

Returns the usable width for out. As the width of out:

  1. If out is assigned to a tty device, its width is used.

  2. Otherwise, or it could not get the value, the COLUMN environment variable is assumed to be set to the width.

  3. If COLUMN is not set to a non-zero number, 80 is assumed.

And finally, returns the above width value - 1.

  • This -1 is for Windows command prompt, which moves the cursor to the next line if it reaches the last column.

Ruby Core © 1993–2022 Yukihiro Matsumoto
Licensed under the Ruby License.
Ruby Standard Library © contributors
Licensed under their own licenses.