From: "Jon A. Lambert" <jlsysinc@...>
Date: 2005-04-27T06:26:32+09:00
Subject: Re: Is Ruby grammar context free?

Peter Suk wrote:
> Something like this runs under Ruby 1.8.  I believe this construction
> is not context free, if the language requires heredoc beginning and
> ending delimiters to be paired.  (Which Ruby seems to.  It throws a
> syntax error if I leave out the second foo.)  Note that you can nest
> the beginning of the heredoc arbitrarily.

I just noticed it also breaks operator continuation.
Assuming your myfunc returned a string..

This is a syntax error.

myfunc(<<"THIS", 23, <<'THAT') + 
"moo"
Here's a line
or two.
THIS
and here's another.
THAT

This is okay.

myfunc(<<"THIS", 23, <<'THAT') + "moo"
Here's a line
or two.
THIS
and here's another.
THAT