proper tail calls

Jon Zeppieri jaz at bu.edu
Mon Jan 21 13:54:43 PST 2008


On 1/21/08, Igor Bukanov <igor at mir2.org> wrote:

> ES4 does not guarantee that. Moreover, in most current implementations
> of ES3 the unreachable objects do consume space until GC collects
> them, but with a conservative GC even that can not be relied upon.

The "until GC collects them" part does not modify what I wrote.  When
I use the phrase "does not consume space," I do not mean that the data
must not exist anywhere in the computer's memory.  I mean only that
the data is not live.  Unreachable objects do not consume space
precisely because they can be collected and their space re-used.
Whether or not they have actually been collected is wholly irrelevant.
 From the point of view of the running program, an unreachable object
simply doesn't exist.

Your point about conservative GC is well taken, but that's the price
one pays for using an approximate method of reclaiming memory.

-Jon



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