From: Robert Klemme <shortcutter@...>
Date: 2007-10-23T16:50:54+09:00
Subject: Re: another (simple!) eval question!

2007/10/23, mouse_059 <kmouse@gmail.com>:
> greetings Rubyists,
>
> Still trying to wrap my head around metaprogramming.
>
> def analyze(args)
>   # stuff
>   # total is defined up here and is equal to some amount of seconds
> elapsed (say 100,000)
>
>   day, hour, min = 0, 0, 0
>   loop do day += 1; total -= 86400; break if total < 0; end; day -= 1;
> total += 86400
>   loop do hour += 1; total -= 3600; break if total < 0; end; hour -=
> 1; total += 3600
>   loop do min += 1; total -= 60; break if total < 0; end; min -= 1;
> total += 60
>
>   puts "your total is #{day} days, #{hour} hours, #{min} mins,
> #{total} secs"
> end
>
> as you can see, i'd like to refactor that so i just have to
>   dotime( :day, 86400 )
>   dotime( :hour, 3600 )
>   dotime( :min, 60 )             (i can hardcode 'total' in the
> function, doesn't matter?)
>
> But no eval I use works, either the eval isn't defined for my class
> (assume main:Object) or I get "no method for + (nilpointer).  I read
> about how you shouldn't use string eval, etc.  A simple pointer to
> some help would be awesome!  Thanks guys.
>
> PS, if a time function does this, don't spoil the metaprogramming for
> me?  I'd like to learn anyway.  :)

I have no idea why you think there should be an eval in there.

What I'd do: I'd put sizes into an array and use that together with
modulus calculations to split up seconds into years, months, days etc.

Kind regards

robert