From: Robert Klemme <shortcutter@...>
Date: 2007-10-12T21:03:35+09:00
Subject: Re: Syntax error when redefining >> operator to take a block

2007/10/12, John Woods <jqwoods@gmail.com>:
> I'm trying to redefine the >> operator for a particular class such that
> it takes a block as its argument. It works if I invoke the redifined >>
> operator using "." syntax, but causes a syntax error otherwise.
>
> This code illustrates my problem:
>
> class C
>   def >>(&block)
>     block.call("inside >>")
>   end
> end
>
> c = C.new
> c.>> { |x| puts x } # outputs "inside >>"
> #c >> { |x| puts x } # syntax error, if uncommented
>
> This is the syntax error reported:
>
> test.rb:10: syntax error, unexpected '|', expecting '}'
> c >> { |x| puts x }        # syntax error, if uncommented
>         ^
> test.rb:10: syntax error, unexpected tIDENTIFIER, expecting kDO or '{'
> or '('
> c >> { |x| puts x }        # syntax error, if uncommented
>                  ^
>
> Any pointers? Thanks.

Redefining operator behavior cannot change Ruby's syntax.  >> is with
a block is just not valid Ruby syntax - as you have seen.

robert