From: dblack@...
Date: 2006-02-12T11:42:42+09:00
Subject: Re: Parse error within Regexp

Hi --

On Sun, 12 Feb 2006, Mauricio Fernandez wrote:

> On Sun, Feb 12, 2006 at 01:34:55AM +0900, Yukihiro Matsumoto wrote:
>> |user@host:~$ ruby -e '"".scan / ,/'
>> |-e:1: parse error, unexpected ','
>> |"".scan / ,/
>> |           ^
>> |-e:1: unterminated string meets end of file
>>
>> |I suppose this is not the intended behaviour. What do you
>> |think?
>>
>> Ruby interpreted '"".scan / ,/' as
>>
>>   ("".scan) / ,/
>>
>> i.e. the first slash was considered as a division operator.  You need
>> to tell Ruby that is a regular expression, by reforming the expression.
>
> Would something like this make sense?
>
> $  ./ruby19 -e '"".scan / ,/'
> -e:1: syntax error, unexpected ','
> "".scan / ,/
>           ^
> -e:1: unterminated regexp meets end of file
>                  ========

I'm not sure the "unterminated string" makes sense as the error
message, but I don't think it's an unterminated regex either.  It
seems that Ruby sees the first / as division, so it doesn't consider
itself to be in mid-regex.  If it thought it was in mid-regex, it
would presumably keep going and it would find that the regex *is*
terminated.

I guess it's really a CommaDivisionError :-)


David

-- 
David A. Black (dblack@wobblini.net)
Ruby Power and Light (http://www.rubypowerandlight.com)

"Ruby for Rails" chapters now available
from Manning Early Access Program! http://www.manning.com/books/black