def x64.mid
import bend-kit-hash@0.3.0.2/hash.bend as Hashimport Base
import bend-kit-bytes@0.3.3.0/bytes.bend as Bytes
582def x64.mid(+len: U32, r: Array<U32> & W64) -> Bytes.Bytes & W64:
583 (a, h) = r
584 x64.rest(len, dfrom(~W64, ~x64.word, U32.to_nat(((len .&. 31) >> 3n : U32)), a, ((len >> 5n) << 3n : U32), W64.add(h, W64{0, len})))