On Sat, May 09, 2020 at 02:56:19PM +0000, Alan Mackenzie wrote:

[...]

> I don't know precisely what a "place" is [...]

I think the best metaphor (it's metaphors all the way down, isn't it)
is an "lvalue". Something you can assign to (but if you use the same
"thing" whithin an expression, you get its value). Thing is, in C
an lvalue isn't a first-order object [1], you can't push it around.
Lisp, OTOH...

Cheers
[1] Well, it isn't really a first order object in Lisp either,
   but your code can pretend, up to a certain point.
-- t