Moving all the string predicates from _std.scm to _system.scm (and the previous additions of (declare (not interrupts-enabled)) improved the speed of k-nucleotide on my ppc64 mac by about 15%:

43.511u 0.640s 0:44.69 98.7% 0+0k 0+3io 0pf+0w

to

36.893u 0.448s 0:37.45 99.6% 0+0k 0+0io 0pf+0w

The improvement is most noticeable for short strings of one or two characters; in k-nucleotide, for example, the times go from

4924 ms real time 4912 ms cpu time (4900 user, 12 system) no collections 2320 bytes allocated no minor faults no major faults

to

4019 ms real time 4016 ms cpu time (4010 user, 6 system) no collections 7632 bytes allocated no minor faults no major faults

for one-character strings in all-counts.

Brad