From: Brad Phelan <phelan@...>
Date: 2007-05-22T00:50:03+09:00
Subject: Re: How to adopt "Python Style" indentation for Ruby

bbiker wrote:
> On May 21, 3:32 am, Brian Candler <B.Cand...@pobox.com> wrote:
>> On Mon, May 21, 2007 at 03:53:25PM +0900, Giles Bowkett wrote:
>>> What would it take to write a Ruby pre-processor which parsed Ruby
>>> written in a Pythonic style and turned it into actual valid Ruby? Or
>>> even a Ruby library like Xavier's Perl example, which allows you to
>>> code Ruby as if it were Python after just requiring the library? The
>>> original post's main argument was that indentation is a stable,
>>> consistent shorthand for Ruby's end statements. If all you're looking
>>> to do is use tabs as syntactic sugar, then it should be pretty easy to
>>> just write something which knows how to translate a sequence of tabs
>>> in and tabs out into a series of end statements at the end.
>> Actually, I'd happily settle for something simpler: a pretty-printer which
>> just reads (normal) Ruby and re-outputs it with standard indentation.
>>
>> This would immediately solve the problem of "where did I miss out an 'end'
>> statement?" - you'd just pipe it into this utility and inspect. In the past
>> I've had to resort to binary chops to solve this: copy source.rb to x.rb and
>> remove chunks of method definitions until I find the offending one. This is
>> painful.
>>
>> As an alternative: the existing Ruby parser could be modified to spit out a
>> warning whenever it sees non-standard nesting, e.g. "end at line <x> doesn't
>> align with start of block/method at line <y>". It only need do this for an
>> 'end' which is at the start of a line.
>>
>> Regards,
>>
>> Brian.
> 
> I use Arachono Ruby IDE. Its editor has a feature whereby I can select
> a number of lines to comment out or uncomment the lines. This makes
> finding the missing end fairly easier.
> 
> I find python indentation much harder to read. For my use, I rather
> stick with the "end"s.
> 

I've tried posting several times without success ... here again.

http://xtargets.com/snippets/posts/show/68

shows a partial solution to your challenge by overloading require. It is
a quick hack but shows you how to write your own pre-processor. The
new require checks to find files of type .pyrb and then coverts them
to .rb files before loading them.

--
Brad Phelan
http://xtargets.com