Levin Alexander <levin / grundeis.net> writes:

> Hi,
>
> I'd like to propose Fixnum#to_a:
>
>   class Fixnum
>     def to_a(base=10,min_length=0)
>       self.to_s(base).rjust(min_length).split(//).map { |c| c.to_i(base) }
>     end
>   end
>
>   12345.to_a #=> [1,2,3,4,5]
>   42.to_a(2) #=> [1,0,1,0,1,0]
>   23.to_a(4,5) #=> [0,0,1,1,3]
>   -10.to_a #=> ???
>
> This relies on to_s and therefore does not work with a base > 36.  I
> don't know how this should word for negative numbers.

It should be twos-complement for negative numbers, of course. ;-)

> Maybe the default base should be 2 to be consistent with Fixnum#[]
>
> Thoughts?

IMO a useful method, *but*: Don't call it #to_a.  to_a has certain
duck-typing aspects, and this usage is too rare to be triggered a lot
(just think of a = 42; b = [*a]).

Also, you may want to extend it to be like APL's "encode" (tack), so you
can do stuff like:

1776.encode(8)                 # => [1, 0, 2, 2]  (octal)
105246.encode(0, 1760, 3, 12)  # => [1,     1163,  1,    6]
                               #    [miles, yards, feet, inches]

Then, we'd also need an "decode":

  [14,   12,    20,      51].decode(0, 24, 60, 60)  # => 1254057
# [days, hours, minutes, seconds]

(The examples were taken from "APL\360 Primer, Student Text, IBM, 1969".)

> Viele Grüße,
> Levin
-- 
Christian Neukirchen  <chneukirchen / gmail.com>  http://chneukirchen.org