R. Kent Dybvig scripsit:
> Global parameters are typically but not always set once and forgotten; an
> application might change the collection parameters, for example, to suit
> different modes of operation. It generally doesn't make sense to localize
> them, however, or they would be defined as thread parameters.
Why not just use ordinary Scheme top-level variables, then, and use
SET! to change them on the occasions when it might be required?
Why use separate machinery for them?
OT: I've noticed a tendency in Scheme libraries to eschew global value
definitions for functions that return a constant value. Has anyone
else noticed this (I can't point to evidence offhand), and does anyone
know why?
> In contrast, a much wider range of parameters are thread parameters:
[examples snipped]
That's the sort of thing I'd expect to use parameters for, when localizing
is important.
--
When I'm stuck in something boring John Cowan
where reading would be impossible or (who loves Asimov too)
rude, I often set up math problems for cowan_at_ccil.org
myself and solve them as a way to pass http://www.ccil.org/~cowan
the time. --John Jenkins
Received on Sun Feb 11 2007 - 00:33:04 UTC