Tomek Sowiński wrote:
Don napisał:
LEAKY FUNCTIONS
Define a 'leaky' pure function as a pure function which can return
heap-allocated memory to the caller, ie, where the return value or a
parameter passed by reference has at least one pointer or reference
type. This can be determined simply by inspecting the signature. (Note
that the function does not need to be immutably pure).
The interesting thing is that heap allocation inside non-leaky pure
functions behaves like stack allocation. When you return from that
function, *all* those variables are unreachable, and can be discarded en
masse. Here's an idea of how to exploit this.
THE PURE HEAP
[snip]
I'm far from being a GC expert but I think Java having identified such cases
with escape analysis just puts locally allocated objects on the stack.
That works for the non-leaky function itself, but it doesn't help for
the functions it calls.
Couldn't we too? Your mark & release "pure heap" scheme looks alright but this
seems simpler.
The notion of "non-leaky" functions can be useful either way.
