On Monday, 15 December 2014 at 02:45:04 UTC, Walter Bright wrote:
1. All inout actually does is reduce code copy/pasta, it is not
critical.
Being forced to duplicate every single function in two flavors to
actually make scope system usable? This is as much critical as it
can be.
2. This is what scope inference is all about.
Which only works with templates and lack of scope on arguments
does not affect function body -> templates are not necessary,
same as inout.
2) at least optional transitivity to be able to express to
protect with scope
data referenced by slice or owned linked list referenced from
root node.
1. that won't work unless scope is a type constructor
I know and this is why I am leaning toward it being qualifier
despite all related issues.
2. it can be achieved by using wrappers that only allow
by-scope references to their data (RC is an example of such a
wrapper)
It is viral approach and backwards incompatible one - we can't
change signatures of Phobos functions to return Wrapped!(char[])
instead of char[] for example. While theoretically possible I
can't call this approach practical - not until see some
convincing application example.
In your tree example I would have never wanted scope
protection of one specific
node of such tree - but a transitive scope protection of whole
tree view
available through on of node pointers/references. It doesn't
matter who and how
owns the data for borrowship implementation - only thing that
matters that _it
is not me_.
As I explained to Manu, transitive scope makes things like
doing a symbol table lookup, then putting a pointer to the
found symbol in an AST, not workable.
This sounds totally against my understanding of scope. I want
scope exactly to prohibit such actions. However it is possible in
slightly modified way - where you don't directly insert pointer
to AST but use public method of AST control structure that checks
if supplied scope pointer belongs to list of nodes it owns and
casts away scope after that.
