SBCL 循环中缺少 Consing
Absence of Consing in SBCL loop
* (defparameter lst (make-list 1000))
LST
* (time (loop for x in lst
for i from 0
unless (= i 500)
collect x))
Evaluation took:
0.000 seconds of real time
0.000000 seconds of total run time (0.000000 user, 0.000000 system)
100.00% CPU
47,292 processor cycles
0 bytes consed
SBCL 如何使用 0 字节 consed 构建 return 列表？
您的测试用例对于 time 来说太小了。试试 (defparameter lst 100000).
Evaluation took:
0.003 seconds of real time
0.003150 seconds of total run time (0.002126 user, 0.001024 system)
100.00% CPU
8,518,420 processor cycles
1,579,472 bytes consed
* (defparameter lst (make-list 1000))
LST
* (time (loop for x in lst
for i from 0
unless (= i 500)
collect x))
Evaluation took:
0.000 seconds of real time
0.000000 seconds of total run time (0.000000 user, 0.000000 system)
100.00% CPU
47,292 processor cycles
0 bytes consed
SBCL 如何使用 0 字节 consed 构建 return 列表？
您的测试用例对于 time 来说太小了。试试 (defparameter lst 100000).
Evaluation took:
0.003 seconds of real time
0.003150 seconds of total run time (0.002126 user, 0.001024 system)
100.00% CPU
8,518,420 processor cycles
1,579,472 bytes consed