Range as conditional expr

ruby-talk
1

Hi,

I am reading "Programming Ruby" [a.k.a. Pickaxe]
and I found example

···

---
  while gets
    print if /a/ .. /e/
  end
---
but one does not work. However, after changing it to:
----
  while gets
    print if (/a/=~$_) .. (/e/=~$_)
  end
---
it works.
But, what is the problem with the first version?

Regards

2

In the Second Edition of the Pickaxe, on page 68 it says:

    In older versions of Ruby, bare ranges could be used as
    conditions in if, while, and similar statements. You
    could, for example, have written the previous code
    fragment as

  while gets
      print if /start/../end/
  end

    This is no longer supported. Unfortunately, no error is
    raised; the test will simply succeed each time.

Hope this answers your question.

Cheers

omirek10@poczta.onet.pl wrote:

···

Hi,

I am reading "Programming Ruby" [a.k.a. Pickaxe]
and I found example
---
  while gets
    print if /a/ .. /e/
  end
---
but one does not work. However, after changing it to:
----
  while gets
    print if (/a/=~$_) .. (/e/=~$_)
  end
---
it works.
But, what is the problem with the first version?

Regards

3

Thanks Steve. I need to obtain 2nd edition indeed.

Regards