On 01/19/2012 01:52 AM, Jonathan M Davis wrote:
On Thursday, January 19, 2012 01:38:23 Alex Rønne Petersen wrote:
But couldn't that be considered leaking an implementation detail of lazy
values? Or is this intentional design?
The language requires that lazy parameters be accessed with (). That leaks the
fact that the variable is lazy into the function body, but whether it leaks
how lazy parameters are implemented is debatable. The same syntax could be
used with a different implementation underneath the hood.
But the fact that you have to use double parens on a lazy delegate isn't
leaking any kind of implemenatation detail. It's the natural extension of the
syntax for lazy. var() gives you the value of the lazy parameter var, and so
if you want to call var (or use opCall or it), then you need another set of
parens - var()().
Whether requiring parens on lazy parameters is a good design decision is
debatable,
They are only required if you want to call a lazy delegate/function
pointer. They are optional in all other cases.
but I don't see any leaking of implementation details in it. The
syntax chosen was probably chosen because it's implemented with a delegate,
but the fact that it's implemented with a delegate is still an implementation
detail which could theoretically be changed.
