More Concatenation

I did some quick benchmarks in Go. (I really like how that ability is part of the standard tools.) Here are some results. As with any benchmark, don't take them as exact. Changing the parameters of the benchmarks gives varying numbers but with the same overall result.

Buffer	37322 ns/op	51104 B/op	10 allocs/op
Array	49456 ns/op	53632 B/op	17 allocs/op
Linked	122558 ns/op	54047 B/op	1010 allocs/op
Merge	311005 ns/op	323552 B/op	1998 allocs/op
Naive	2225408 ns/op	5371680 B/op	999 allocs/op

An "op" in this case was appending 10 characters, 1000 times.

Some observations:

• Naive concatenation is indeed bad, both in speed and memory
• Almost anything is much better than the naive approach
• As expected, a buffer is the best in both speed and memory
• An array of substrings (without any merging) does surprisingly well
• For an immutable option, a linked list isn't too bad
• A merge tree was not such a good idea