From: David Vallner <david@...>
Date: 2006-02-10T22:21:22+09:00
Subject: Re: Ruby 1.8.4 behaviour - 2 questions

Dňa Piatok 10 Február 2006 04:08 ara.t.howard@noaa.gov napísal:
> hmmm.  if that's the case (possible string) i'd use
>
>    target_f += Float(source_f)
>
> since
>
>    harp:~ > ruby -r yaml -e'  target_f = 40.0;  y target_f += "junk".to_f 
> ' --- 40.0
>
> and
>
>    harp:~ > ruby -r yaml -e'  target_f = 40.0;  y target_f += Float("junk")
>  ' -e:1:in `Float': invalid value for Float(): "junk" (ArgumentError) from
> -e:1
>
> but
>
>    harp:~ > ruby -r yaml -e'  target_f = 40.0;  y target_f += Float("2")  '
>    --- 42.0
>
> cheers.
>
> -a

Well, to_f coerces any junk to 0.0. It depends in that case whether you want 
magic or exact behavior. However, Float(nil) results in a TypeError.

But this should work as desired -and- not accept any line noise for source_f:

	target_f += Float(source_f || nil)

David Vallner