From: Daniel Martin <martin@...>
Date: 2006-07-12T03:12:49+09:00
Subject: Re: Ruby regexp spec.

"Simon Strandgaard" <neoneye@gmail.com> writes:

> Have a look here:
>
> http://www.geocities.jp/kosako3/oniguruma/doc/RE.txt

That's nice, but it doesn't document ruby's Regexp engine, at least
not the one in Ruby 1.8.4; the document says:

(?<=subexp)        look-behind

But:

irb(main):032:0> Regexp.new('(?<=abc)')
RegexpError: undefined (?...) sequence: /(?<=abc)/
        from (irb):32:in `initialize'
        from (irb):32
        from :0

I suspect that this documents what will be, in the Ruby 2.0 that's
going to have easy built-in support for unicode in all its glory.

That still leaves the current engine undocumented.