[Swift-devel] dataset marking

[Mihael Hategan]

That's my understanding of it, too.

There are some special cases. Static mappers. They know how many
elements there are in an array, so for those the array can be closed as
soon as they are mapped. But this applies to the other problem.

On Thu, 2007-12-06 at 22:22 +0000, Ben Clifford wrote:
> The present SwiftScript->karajan compiler contains a bunch of code to do 
> 'dataset marking'.
> 
> Its a bit tangled, as the other code has evolved around it, and my 
> understanding of it is correspondingly tangled. So please speak out if 
> there is a problem with the following.
> 
> The purpose of the dataset marking is to identify which dataset 
> declarations in a SwiftScript program are inputs (to the whole workflow) 
> and mark them as such in the compiled code. A dataset is an input if it is 
> never assigned to; if it is assigned to then it is not an input.
> 
> I worked on some code that changes the way that arrays are closed, by 
> identifying which statements write to a dataset, at compile time.
> 
> This information is also what is needed, I think, to do the above 
> mentioned dataset marking - the same code which finds out that some 
> statements are writing to a dataset will also find out that some datasets 
> have no statements at all writing to them.
>