From: Ken Bloom <kbloom@...>
Date: 2008-10-20T21:09:00+09:00
Subject: Re: a new quotation operator to automatically unindent %q and %Q

On Sun, 19 Oct 2008 21:33:56 -0500, Trans wrote:

> On Oct 19, 5:38 pm, Suraj Kurapati <s...@gna.org> wrote:
>> Hello everyone,
>>
>> Many times I have faced the situation of embedding multi-line strings
>> in my programs while wanting to preserve the indentation of the
>> surrounding code:
>>
>>   module Foo
>>     class Bar
>>       def to_s
>>         %q{
>>           This block of text will,
>>
>>             unfortunately,
>>
>>           contain the indentation of
>>
>>             the
>>                 surrounding
>>                             code!
>>
>>           Unless we manually remove it,
>>           as shown by the gsub() below:
>>
>>         }.gsub(/^          /, '')
>>       end
>>     end
>>   end
>>
>> The same problem occurs for "here documents" as well.  We are forced to
>> manually remove the indentation.
>>
>> I would like to propose a new set of string quotation operators %s and
>> %S which behave just like %q and %Q respectively, except that they are
>> automatically unindented by the Ruby interpreter using the first line
>> of non-whitespace text:
>>
>>   amount_to_unindent = input_string[/\A(?:\r?\n)+([ \t]+)(?=\S)/, 1]
>>   input_string.gsub! /^#{amount_to_unindent}/, ''
>>
>> What do you think?
> 
> Hi--
> 
> This is not an uncommon request. Consider:
> 
>   http://rcrchive.net/rcrs/2
> 
> Long long ago I proposed %l and %L:
> 
>          %l{
>            |This block of text will,
>            |
>            | unfortunately,
>            |
>            |contain the indentation of
>            |
>            |  the
>            |     surrounding
>            |                 code!
>            |
>            |Unless we manually remove it,
>            |as shown by the gsub() below:
>            }
> 
> But matz does not seem to see merit in any of this. I'm not sure why.
> 
> T.

Probably because it can easily be done in a library. See the facets gem's 
String#margin

-- 
Chanoch (Ken) Bloom. PhD candidate. Linguistic Cognition Laboratory.
Department of Computer Science. Illinois Institute of Technology.
http://www.iit.edu/~kbloom1/