On Sun, May 8, 2011 at 8:54 AM, Gregory Ewing <greg.ew...@canterbury.ac.nz> wrote: > Ben Finney wrote: > >> No, I think not. The term “variable” usually comes with a strong >> expectation that every variable has exactly one name. > > I would say that many variables don't have names *at all*, > unless you consider an expression such as a[i] to be > a "name". And if you *do* consider that to be a name, > then clearly one variable can have a great many names. > > What would *you* call a[i]?
a is a variable; i is a variable; a[i] is an expression. It's not a single name, and if you had two variables i and j with the same value, nobody would disagree that a[i] and a[j] ought to be the same thing. That's the whole point of arrays/lists/etc/etc. But if you want to fry your noggin, wrap your head around REXX's compound variables: a=5 b=3 array.a.b="Hello" /* see, this is a two-dimensional array */ c=63/10 array.c="world!" /* see, we can have non-integers as array indices */ d=a+1 result = array.a.b", "array.d.b /* "Hello, world!" */ So what is a "name" in REXX? You have to evaluate the compound variable as a set of tokens, then evaluate the whole thing again, and is that the name? Because the resulting "name" might not be a valid identifier... Yep, it's good stuff. Chris Angelico -- http://mail.python.org/mailman/listinfo/python-list
