pub fn encode_dense(expr: &Expr) -> Result<BitwiseFrame>Expand description
Encodes a bare Expr into a dense BitwiseFrame with structural sharing.
Dense mode assigns every subexpression a pre-order number and, on a
value-equal subtree already emitted, writes a Ref back-reference tag
instead of re-encoding it. It is a deterministic pure function
of the value tree and round-trips by Expr::canonical_eq, but it is
explicitly opt-in: the plain encode_frame and crate::canonical_bytes
stay ref-free so the content-addressing key is unchanged.