From: Peter Marsh <evil_grunger@...>
Date: 2007-06-07T23:47:41+09:00
Subject: Re: What about a 'series' type?

SonOfLilit wrote:
> Actually, the syntax:
> 
> a = Series.new(8) {|i| 5*i**3}
> 
> a.collect{|i| i + 1}.select{|i| i % 2 == 0} # i.e. a is an enumerable 
> object
> 
> is quite cool and might be useful in some cases. The only problem I'm
> trying to solve is that of providing syntax for persistence (e.g. try
> to implement a series of Fibonacci numbers with the iterative
> algorithm using this Series syntax). Perhaps an optional hash argument
> that is used to give initial values to instance variables?
> 
> With persistence, this could be a very useful idiom in many cases, and
> maybe even deserves to be stdlib.
> 
> Aur

The two examples I gave are fairly specific, I didn't really think about 
that. However, I still think a 'series' type would be useful, even if 
the implimentation is different to my example.

Taking prime numbers as an example using the current 'prime' class you 
have to use:

require 'mathn'

primes = Prime.new

etc

With a seires type you could do something like this:

primes = Series.new(Starting_value,Some_block_to_define_serires)

primes[0] = 2
primes[0..2]
>> [2,3,5]

Giving definate advantages, I feel.

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