Class: PP

Inherits:
PrettyPrint show all
Includes:
PPMethods
Defined in:
lib/pp.rb

Overview

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. Note that require 'pp' is needed before redefining #pretty_print(pp).

#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 <[email protected]>

Direct Known Subclasses

IRB::ColorPrinter

Defined Under Namespace

Modules: ObjectMixin, PPMethods Classes: SingleLine

Constant Summary collapse

VERSION = 
"0.5.0"

Class Attribute Summary collapse

Attributes inherited from PrettyPrint

#genspace, #group_queue, #indent, #maxwidth, #newline, #output

Class Method Summary collapse

Methods included from PPMethods

#check_inspect_key, #comma_breakable, #guard_inspect_key, #object_address_group, #object_group, #pop_inspect_key, #pp, #pp_hash, #pp_object, #push_inspect_key, #seplist

Methods inherited from PrettyPrint

#break_outmost_groups, #breakable, #current_group, #fill_breakable, #flush, format, #group, #group_sub, #initialize, #nest, singleline_format, #text

Constructor Details

This class inherits a constructor from PrettyPrint

Class Attribute Details

.sharing_detection ⇒ Object

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



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# File 'lib/pp.rb', line 124

def sharing_detection
  Ractor.current[:pp_sharing_detection]
end

Class Method Details

.mcall(obj, mod, meth, *args, &block) ⇒ Object

:stopdoc:



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# File 'lib/pp.rb', line 115

def PP.mcall(obj, mod, meth, *args, &block)
  mod.instance_method(meth).bind_call(obj, *args, &block)
end

.pp(obj, out = $>, width = width_for(out)) ⇒ Object

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.



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# File 'lib/pp.rb', line 95

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

.singleline_pp(obj, out = $>) ⇒ Object

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

PP.singleline_pp returns out.



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# File 'lib/pp.rb', line 107

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

.width_for(out) ⇒ Object

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.



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# File 'lib/pp.rb', line 78

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