augmenting README

[JeffreySarnoff]

There are no separate docs yet. Considering what ought be mentioned, I am editing the README (to become a PR when clean and of our agreement).

Here is a start with some questions,

• should Static.dynamic become part of the interface example?
• should NDIndex be described as an external export, or is it for special uses?
• how to describe StaticBool with True, True(), False, False()?
• what is a good intro explaining why and where to use this?

Static

Static defines a limited set of statically parameterized types and a common interface that is shared between them. Defining a new static type that conforms with this interface only requires defining the following:

• Static.static(::T) - given the non-static type T return its static counterpart.
• Static.dynamic(::Type{S})- given the static type S return the known non-static type.
• Static.is_static(::Type{S}) - given the static type S return True() (else False())
• Static.known(::Type{S})- given the static type S return the known non-static value.

Fore example, the following would appropriately define the interface for StaticChar

Static.static(x::Char) = StaticChar(x)
Static.dynamic(::Type{StaticChar}) = Char
Static.is_static(::Type{T}) where {T<:StaticChar} = True()
Static.known(::Type{StaticChar{C}}) where {C} = C::Char

Exported Types

• StaticBool, True, False
• StaticInt, StaticFloat64
• StaticSymbol
• NDIndex

[dlfivefifty]

Can you actually explain what a static type is in the readme?

[Tokazama]

I like this so far.

Can you actually explain what a static type is in the readme?

It means known "statically" or at compile time. It's comparable to Val(x) but it functions like whatever x is. This is extremely useful for producing generic code for static and dynamic values (StaticInt and Int).

We should probably find a way of also communicating that this is predominantly for the purpose of overcoming problems with constant propagation. Unlike previous efforts in this area, we're not pushing to have a static counterpart to everything in Base. So the Char example may be a bit misleading because if there is a consistent need for text that is statically known, then we should probably build it into StaticSymbol.