From: Brian Candler <B.Candler@...>
Date: 2007-05-21T16:32:46+09:00
Subject: Re: How to adopt "Python Style" indentation for Ruby

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.