def gz.head

bend-kit-zlib@0.5.1.0 · zlib.bend:663

import Base
import bend-kit-bytes@0.3.3.0/bytes.bend as Bytes

663# ID1 31, ID2 139, CM 8 (DEFLATE), then FLG.
664def gz.head(+p: U32, r: Bytes.Bytes & Maybe<&2, U32>) -> Maybe<&1, Member>:
665  (b, m) = r
666  match m:
667    case None{}:
668      None{}
669    case Some{+w}:
670      gz.magic(U32.is_eq(U32.and(w, 16777215), 559903), U32.shrn(w, 24n), p, b)