From: Albert Schlef <albertschlef@...>
Date: 2009-12-31T14:32:42+09:00
Subject: Re: Why can't I use "or" here?

botp wrote:
> On Thu, Dec 31, 2009 at 10:24 AM, Albert Schlef <albertschlef@gmail.com> 
> wrote:
>> Why? I thought the only diference between "or" and "||" is the
>> precedence.
> 
> yes, so you can do eg
> 
>>> system "pwd" or raise "no command here"
> /home/botp
> => true
> 
>>> system "asdf" or raise "no command here"
> RuntimeError: no command here
> 
> if you know perl, this is no surprise..


It *is* a surprise. In Perl, unlike in Ruby, `func(0 or 1)` *does* 
work....


> 
> as always, there are many ways in ruby, you can use || or the double
> parens override.


Well. it turns out there aren't that many ways in ruby.

I originally tried to do the following:

  some_func(ARGV[0] or raise "You must provide an argument")

I wish it worked. But it doesn't. So I changed it to:

  some_func(ARGV[0] || raise "You must provide an argument")

It still didn't work. So finally I did:

  some_func(ARGV[0] || (raise "You must provide an argument"))

It works. But, I must say, it isn't as beautiful as my original plan. It 
doesn't read as English.
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