From: Marnen Laibow-Koser <marnen@...>
Date: 2009-12-01T03:40:04+09:00
Subject: Re: if statement modifier, with else, warning

Gary Hasson wrote:
> The following statement works fine, even though it generates a warning.
> With regard to "if" and "unless" being used as statement modifiers, a
> manual states: "Obviously, this syntax does not allow any kind of else
> clause."
> 
>   compare_files unless @filename_1 == nil or @filename_2 == nil else
>     @messagetextctrl.append_text("  ==> Please specify files to compare.
> \n")
> 
> Error Msg: "...rb:112: warning: else without rescue is useless"
> 
> Obviously, the statement can be changed to the normal "if-else-end"
> format, but that would not be as Ruby-ish as the above approach.

What would be un-Rubyish about not using the statement modifier?  The 
normal syntax would be far clearer here.

> 
> Is there a good reason why Ruby should not allow "else" to be used as in
> the example above?

Because it would lead to confusing code.  Statement modifiers are fine 
for the simplest cases, but toss in any complexity and you've got chaos.

> 
> Gary

Best,
-- 
Marnen Laibow-Koser
http://www.marnen.org
marnen@marnen.org
-- 
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