From: "David A. Black" <dblack@...>
Date: 2009-03-05T06:19:45+09:00
Subject: Re: Any solutions to Ruby's inconsistencies?

Hi --

C. Dagnon wrote:
> Ruby has definite positives over Java and even other scripting
> languages, but many negatives too.  One negative is the inconsistency of
> how rules seem to be applied in the language and accompanying toolsets.
> Here are a few that have bitten me:
>
>
> 1. I almost immediately got started with Ruby on Rails and loved the
> idea of partials, but then I found that the ||= idiom doesn't work on
> partials' parameters.
>
> <%  my_param_a ||= 1    # Errors out
>      my_param_a = my_param_a ? my_param_a : 1   # works
> -%>
>
> That seemed odd as I thought both were equivalent, and it broke some of
> the trust I had for Ruby.  Not as much as early Rails' use of 2 separate
> variables for RAILS_ENV, but...

I can't duplicate that problem. What error message are you getting?

> 3. Originally I was taught that symbols were the salvation of memory and
> key problems - and they certainly sounded like it.  Up until the point a
> few days later when one (Rails?) map used Symbols and another used
> Strings.  Ouch.
>      Without any explicit typing abilities in the language (optional or
> otherwise?) it seems like the only solution is to return to basic string
> matches:
>      regex = Regexp.compile("^#{matcher.to_s}$", Regexp::IGNORECASE)

You can use some shortcuts there:

   /^#{matcher}$/i

>      key = map.keys.find{ |key| key.to_s =~ regex }
> Yuck.

In 1.9, symbols can be matched against regular expressions. So you can do:

   [:a,:b,:c,:cat].grep(/a/)

I have mixed emotions about the string-like behavior of symbols in 1.9 
(they have methods like #upcase and #succ), but it has the practical 
advantage of making it unnecessary to worry about which you've got if 
you're matching patterns.

> Please let me know how I can supplement my possibly deficient Ruby
> education :)  Relevant discussions or sections of "The Ruby Way"
> appreciated!

There's a book or two due out soon... see below :-)


David

-- 
David A. Black / Ruby Power and Light, LLC
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