with_chop:  5 wallclock secs ( 5.19 usr +  0.00 sys =  5.19 CPU) @ 192.79/s (n=1000)

with_split: 13 wallclock secs (13.14 usr +  0.02 sys = 13.16 CPU) @ 76.01/s (n=1000)

with_substr:  7 wallclock secs ( 6.89 usr +  0.00 sys =  6.89 CPU) @ 145.14/s (n=1000)

              Rate  with_split with_substr   with_chop
with_split  76.0/s          --        -48%        -61%
with_substr  145/s         91%          --        -25%
with_chop    193/s        154%         33%          --