[PEAK] Lessons from the new API

[Jeffrey Harris]

Hi Phillip,

>    foo = trellis.attr(make=dict)

The 'make' keyword sounds great, clear and helpful.

> variable            -> attr
> variable.attributes -> attrs
> variable.attributes.resetting_to -> resetting_attrs
> 
> compute.attributes  -> compute.attrs
> maintain.attributes -> maintain.attrs
> 
> * add a 'make' keyword to 'maintain()'
> * add a 'make()' attribute type, to allow you to create optional 
> computed values, that can be declared writable
> * add a 'make.attrs()' callable, to allow creating multiple make() 
> attributes

All sounds good.

> I am somewhat tempted to also shorten 'compute' to 'calc' and 'maintain' 
> to 'ensure'.    But that's probably pushing it.  On the other hand, 
> 'calc' seems a bit more like it means "side-effect free".  So I'm open 
> to feedback on that, or other suggestions for how to name the central 
> words.

For some reason I much prefer a full verb form to 'calc', perhaps it's 
because my main interaction with 'calc' is when I occasionally run MS 
calc using calc.exe, so I don't think of it as a verb...

I agree calculate sounds more "side-effect free" than compute, but it 
seems marginal to me, maybe not worth the extra two characters.

I'm ambivalent on 'maintain' vs. 'ensure', they both seem reasonably clear.

Sincerely,
Jeffrey