From: "Marcel Molina Jr." <marcel@...>
Date: 2007-06-21T07:27:20+09:00
Subject: Re: Code Critique: check if int or float

On Thu, Jun 21, 2007 at 07:17:53AM +0900, ole __ wrote:
> I'm really starting to like this language. I'm working towards building
> a simple expression evaluator. I couldn't seem to find any methods for
> testing whether a string contains an integer or float. In PHP (where I'm
> from) you've got your is_numeric(). Is there such a method in Ruby?
> 
> Anyway, under the assumption that there wasn't and to learn a bit I
> decided to add the methods i? and f? to String. I was wondering if I
> could get a bit of a critique on this code because I'm still ultra new
> to Ruby.

>> '3s'.to_i
=> 3
>> Integer('3s')
ArgumentError: invalid value for Integer: "3s"
        from (irb):3:in `Integer'
        from (irb):3
>> '3s'.to_f
=> 3.0
>> Float('3s')
ArgumentError: invalid value for Float(): "3s"
        from (irb):5:in `Float'
        from (irb):5
>> '-8e3'.to_f
=> -8000.0
>> Float('-8e3')
=> -8000.0
>> '-8e3'.to_i
=> -8
>> Integer('-8e3')
ArgumentError: invalid value for Integer: "-8e3"
        from (irb):9:in `Integer'
        from (irb):9

You could likely come up with a much cleaner implementation using
Integer() and Float() + rescue ArgumentError.

And about camelCase, it's true, almost no one in Ruby uses
camelCase. I'd recommend just going with the flow and adoption
lowercase_and_underscored.

marcel
-- 
Marcel Molina Jr. <marcel@vernix.org>