I've never tested it but thought reading the file without processing would be faster than reading & then processing.
I guess it would depend on the processing taking long enough to delay the next read.
This is how I [rightly or wrongly] think about the process:
Since AutoLISP doesn't permit multiple processor threads, everything is evaluated in sequence, one function after another, hence, each
read-line expression will not be evaluated until the previous expression has completed evaluation.
One cannot avoid the string processing time - in both examples the string must be separated into two items and hence this processing time is incurred whether performed within the first
while loop, or within a secondary loop; the only difference being that in your code the program must first construct the list before iterating over the same data again to process each string. Whereas in my example, the string processing is performed whilst the list is constructed, and so the data set is only being iterated once.
Though, I've also never tested this theory.
Thanks for your input.
Anytime my friend