From: Robert Klemme <shortcutter@...>
Date: 2007-06-29T06:25:12+09:00
Subject: Re: pretty_print woes

On 28.06.2007 15:42, John Joyce wrote:
> 
> On Jun 28, 2007, at 8:26 AM, Ronald Fischer wrote:
> 
>>>>   require 'pp'
>>>>   ....
>>>>   result=foo(bar)
>>>>   $my_message="The function call foo("+
>>>>       bar.pretty_print_inspect+
>>>>       ") returned: "+result.pretty_print_inspect
>>>>
>>>> This works well most of the time, for example if the values
>>> formatted
>>>> with pretty_print_inspect are arrays or numbers. I get, however, a
>>>> runtime error when calling for String:
>>>>
>>>>   "abc".pretty_print_inspect
>>>> RuntimeError: pretty_print is not overridden for String
>>>>
>>>> Is there a different way to use the module pp, so that its
>>> output goes
>>>> to a string?
>>> irb(main):009:0> puts "foo\"bar".pretty_inspect
>>> "foo\"bar"
>>> => nil
>>
>> Thanks a lot! Nearly perfect!! (Actually, I use pretty_inspect.chomp,
>> because pretty_inspect adds a \n to the formatted string).
>>
>> Ronald
>>
> Actually, puts is adding that \n to the string, but your result is what 
> you wanted!

No, #pretty_inspect actually adds it:

irb(main):001:0> "a".pretty_inspect
=> "\"a\"\n"

Ronald, #pretty_inspect can actually add newlines itself:

irb(main):004:0> ha=(1..10).inject({}) {|h,i| h[i] = Array.new(i, i); h}
=> {5=>[5, 5, 5, 5, 5], 6=>[6, 6, 6, 6, 6, 6], 1=>[1], 7=>[7, 7, 7, 7, 
7, 7, 7], 2=>[2, 2], 8=>[8, 8, 8, 8, 8, 8, 8, 8],
  3=>[3, 3, 3], 9=>[9, 9, 9, 9, 9, 9, 9, 9, 9], 4=>[4, 4, 4, 4], 
10=>[10, 10, 10, 10, 10, 10, 10, 10, 10, 10]}
irb(main):005:0> ha.pretty_inspect
=> "{5=>[5, 5, 5, 5, 5],\n 6=>[6, 6, 6, 6, 6, 6],\n 1=>[1],\n 7=>[7, 7, 
7, 7, 7, 7, 7],\n 2=>[2, 2],\n 8=>[8, 8, 8, 8, 8
, 8, 8, 8],\n 3=>[3, 3, 3],\n 9=>[9, 9, 9, 9, 9, 9, 9, 9, 9],\n 4=>[4, 
4, 4, 4],\n 10=>[10, 10, 10, 10, 10, 10, 10, 10,
10, 10]}\n"
irb(main):006:0> puts ha.pretty_inspect
{5=>[5, 5, 5, 5, 5],
  6=>[6, 6, 6, 6, 6, 6],
  1=>[1],
  7=>[7, 7, 7, 7, 7, 7, 7],
  2=>[2, 2],
  8=>[8, 8, 8, 8, 8, 8, 8, 8],
  3=>[3, 3, 3],
  9=>[9, 9, 9, 9, 9, 9, 9, 9, 9],
  4=>[4, 4, 4, 4],
  10=>[10, 10, 10, 10, 10, 10, 10, 10, 10, 10]}
=> nil
irb(main):007:0>

Kind regards

	robert