time complexity of string +=

[Peng Yu]

Hi,

It seems that the time complexity of string += is super-linear. Is it
so? Should it be made to be linear instead of super-linear?

x=; time for ((i=0;i<100;++i)); do x+=a; done; echo "${#x}"

real    0m0.001s
user    0m0.001s
sys     0m0.000s
100

x=; time for ((i=0;i<10000;++i)); do x+=a; done; echo "${#x}"

real    0m0.058s
user    0m0.057s
sys     0m0.000s
10000

x=; time for ((i=0;i<1000000;++i)); do x+=a; done; echo "${#x}"

real    0m20.997s
user    0m20.969s
sys     0m0.017s
1000000


-- 
Regards,
Peng