Formatting Ruby's prettyprint

问题

Is it possible to change the width that prettyprint (require 'pp') uses when formatting output? For example:

"mooth"=>["booth", "month", "mooch", "morth", "mouth", "mowth", "sooth", "tooth"]
"morth"=>["forth",
 "mirth",
 "month",
 "mooth",
 "morph",
 "mouth",
 "mowth",
 "north",
 "worth"]

The first array is printed inline because it fits within the column width prettyprint allows (79 characters)... the second is split onto multiple lines, because it does not. But I can find no method for changing the column that this behavior starts on.

pp depends on PrettyPrint (which has ways to allow different widths for the buffer). Is there any way to change the default column width for pp, without rewriting it from scratch (accessing PrettyPrint directly)?

Alternately, is there a similar ruby gem that provides this functionality?

回答1:

#!/usr/bin/ruby1.8

require 'pp'
mooth = [
  "booth", "month", "mooch", "morth",
  "mouth", "mowth", "sooth", "tooth"
]
PP.pp(mooth, $>, 40)
# => ["booth",
# =>  "month",
# =>  "mooch",
# =>  "morth",
# =>  "mouth",
# =>  "mowth",
# =>  "sooth",
# =>  "tooth"]
PP.pp(mooth, $>, 79)
# => ["booth", "month", "mooch", "morth", "mouth", "mowth", "sooth", "tooth"]

To change the default with a monkey patch:

#!/usr/bin/ruby1.8

require 'pp'

class PP
  class << self
    alias_method :old_pp, :pp
    def pp(obj, out = $>, width = 40)
      old_pp(obj, out, width)
    end
  end
end

mooth = ["booth", "month", "mooch", "morth", "mouth", "mowth", "sooth", "tooth"]
pp(mooth)
# => ["booth",
# =>  "month",
# =>  "mooch",
# =>  "morth",
# =>  "mouth",
# =>  "mowth",
# =>  "sooth",
# =>  "tooth"]

These methods also work in MRI 1.9.3

回答2:

Found "ap" aka "Awesome_Print" useful as well from git-repo

Code used to test pp and ap:

require 'pp'
require 'ap' #requires gem install awesome_print 

data = [false, 42, %w{fourty two}, {:now => Time.now, :class => Time.now.class, :distance => 42e42}]
puts "Data displayed using pp command"
pp data

puts "Data displayed using ap command"
ap data

O/P from pp vs ap:

Data displayed using pp command
[false,
 42,
 ["fourty", "two"],
 {:now=>2015-09-29 22:39:13 +0800, :class=>Time, :distance=>4.2e+43}]

Data displayed using ap command
[
    [0] false,
    [1] 42,
    [2] [
        [0] "fourty",
        [1] "two"
    ],
    [3] {
             :now => 2015-09-29 22:39:13 +0800,
           :class => Time < Object,
        :distance => 4.2e+43
    }
]

Reference:

Stackoverflow posting
Web citing

来源：https://stackoverflow.com/questions/2112016/formatting-rubys-prettyprint

标签

ruby

pretty-print