Well, your operations are a bit suspicious here.
`result_raw[0..0].parseHexInt()` could be replaced with something like
`result_raw[0].parseHexDigit()` where parseHexDigit is defined like:
proc parseHexDigit(ch: char): int =
case ch
of '0'..'9': ch.ord - '0'.ord
of 'a'..'f': ch.ord - 'a'.ord + 10
of 'A'..'F': ch.ord - 'A'.ord + 10
else: raise some error
Run
Although this wouldn't be monstrously faster than parsing the string, you are
talking about optimizing simple slice operations here, so might as well go for
the most.
When you do `result.removeSuffix(spaces(tailLen))`, are you purposefully also
accounting for the case where result doesn't exactly end with tailLen spaces?
If you are _sure_ that result ends with tailLen spaces and you have to remove
those spaces, then you could just do `result.setLen(result.len - tailLen)`.
Even further, you can reduce the last 2 statements to `result =
result_raw[1..^(tailLen + 1)]`.
I don't know if Nim has any comprehensive ways of viewing string slices without
copying yet despite all the work done on borrow checking, but I'm guessing you
do want `result` to be a new, unique string so it wouldn't matter. What I will
say is that `newStringStream` always creates a copy of a string, so you could
create only 1 copy without using it (`let result_raw = raw_string` is an extra
copy), but you must create 2 copies in this case if you want to use a
stringstream.
