[theory] What is a type?

[Ali]

On Sunday, 10 October 2010 at 12:28:32 UTC, Justin Johansson 
wrote:
> Now having hopefully described that a type is something
> that might well have multiple orthogonal aspects to its
> identity, how would one go about implementing a dynamic
> language with such a complex type system in D?
>
> I realize that this is a complex topic and that it might
> require better articulation than so far I have given.
>
> Nevertheless, thanks for all replies,
> Justin Johansson

If you want to learns the ins and outs of types, this books comes 
highly recommended

https://www.cis.upenn.edu/~bcpierce/tapl/