Background question on working assumptions about TOSCA types.

[Dale Moberg <dmoberg@axway.com>]

Hi,

 

Last Monday someone brought up whether we should think about TOSCA types as something like JS prototypes or more like OO classes.

 

This question made me realize that I did not know what we are/were/will be assuming about TOSCA types, but I hope it will be something simple and not involve us in something like the “Lambda cube”  and “Rank-N polymorphism” and the all the distinctions of the programming-language, type theorists behind Coq, ML, F, Haskell and the like.

 

Here is what I had been assuming we meant by TOSCA types:

 

1. types can have subtypes

2. there is inheritance  by subtypes.

3. subtypes inherit from at most one supertype (no multiple inheritance, no diamond)

 

Some things unclear to me from our documentation so far:

 

1. can anything (method,variable,value,default,etc.) be overridden in a subtype?

2. if there are abstract types, how do we tell when a type can be the type of, for example, a given node template? (we have 3 levels now, is the first level abstract and the other two concrete enough to have instances?)

 

I reserve the right to ask a few more questions depending on what answers I hear!

 

[Matt, I have not finished all your slides, and maybe the answers were implicit somewhere, but I wasn’t smart enough to extract them.]

 

Bye

Dale Moberg