Question

Which language is smart so that it could understand variable a = 0 , 20, ..., 300 ? so you could easily create arrays with it giving step start var last var (or, better no last variable (a la infinite array)) and not only for numbers (but even complex numbers and custom structures like Sedenion’s which you would probably define on your own as a class or whatever…)

Point is, find a language or algorithm usable in a language that can cach the law of how array of variables you’ve given (or params of that variables) change. And compose using that law a structure from which you would be able to get any variable(s).

To everyone – examples you provide are very helpful for all beginners out there. And at the same time are the basic knowledge required to build such ‘Smart Array’ class. So thank you wary much for your enthusiastic help.

As JeffSahol noticed

all possible rules might include some
that require evaluation of some/all
existing members to generate the nth
member.

So it is a hard Question. And I think language that would do it ‘Naturally’ would be great to play\work with, hopefully not only for mathematicians.

Answer 1

Haskell:

Prelude> let a=[0,20..300]
Prelude> a
[0,20,40,60,80,100,120,140,160,180,200,220,240,260,280,300]

btw: infinite lists are possible, too:

Prelude> let a=[0,20..]
Prelude> take 20 a
[0,20,40,60,80,100,120,140,160,180,200,220,240,260,280,300,320,340,360,380]