From: Robert Klemme <shortcutter@...>
Date: 2009-01-29T21:55:30+09:00
Subject: Re: error with regular expression inside eval block

2009/1/29 Barun Singh <barunio@gmail.com>:
> Iñaki Baz Castillo wrote:
>> El Jueves, 29 de Enero de 2009, Barun Singh escribió:
>>>
>>>  >> outputs "nil" to the screen
>>>
>>> Could someone explain why the eval statement returns an incorrect result
>>> for the regexp match?  Thanks...
>>
>> It works if you escape the \ with \\ :
>>
>>   eval %Q{'1' =~ /^[\\d]+$/}
>>   => 0
>>
>> Not sure why the \ must be escaped into a block code.
>
> Ah, thanks that worked. I wonder why extra escaping is needed just
> because it's in a block...

It's not a block - it's a doubly quoted string!

Ruby version 1.8.7
irb(main):001:0> %Q{foo}
=> "foo"
irb(main):002:0> %Q{foo}.class
=> String
irb(main):003:0> %Q{foo\\no}
=> "foo\\no"
irb(main):004:0> %Q{foo\no}
=> "foo\no"
irb(main):005:0> puts %Q{foo\no}
foo
o
=> nil
irb(main):006:0> puts %Q{foo\\no}
foo\no
=> nil

Kind regards

robert


-- 
remember.guy do |as, often| as.you_can - without end