G'day everyone
I'm not sure how I'd handle this, as I'm just thinking about it now, but how would one implement a (for) that had two indices rather than the usual one?
For example (pseudopseudocode):
for i = 1 to 10 with j=20 to 2 step -2 do
println i,j
next
The usual thing is to have the for j inside the for i and to get about 100 results. I was thinking more of getting as many results as it takes for either i or j to terminate. That is, if i gets to 10 before j gets to 2 then terminate or vice versa.
I may come up with something soon, but if anyone wants to offer a solution, I'd be very interested.
Kind regards,
Bruce.
(setq j 20)
(for (i 1 10 1 (= j 0))
(println (string "i=" i "j=" j))
(setq j (- j 2))
)
Quote from: "HPW"
(setq j 20)
(for (i 1 10 1 (= j 0))
(println (string "i=" i "j=" j))
(setq j (- j 2))
)
Wow, would never of thought of that approach. Thanks!!
Kind regards,
Bruce.
Quote from: "axtens"
Quote from: "HPW"
(setq j 20)
(for (i 1 10 1 (= j 0))
(println (string "i=" i "j=" j))
(setq j (- j 2))
)
However, what I ended up doing was:
(setq j ?TestRange2Low)
(while (and (!= i ?TestRange1High) (!= j ?TestRange2High))
(begin
(inc i ?TestIncr1)
(inc j ?TestIncr2)
)
)
which, whilst not brilliant, does work. I suppose what I was thinking of was some new kind of syntax that would enable me to set up a co-enumeration, e.g.
(co-for (i 1 10 1) (j 20 2 -2) (begin ... ) )
--Bruce