Documentation

FNV-1a 64-bit offset basis (used as the initial accumulator). The literal is unsigned and exceeds Int range, so we round-trip through Word64 to get the well-defined two's-complement bit pattern.

Sentinel mixed in for a null slot, so Nothing does not hash the same as a present value with equal bits (e.g. Just 0). A fixed distinctive constant keeps null hashing deterministic; a real value equal to it collides only rarely.

Mix an Int into the accumulator with an FxHash-style step. The rotate diffuses each value's bits before the next is folded in, avoiding the structured collisions a plain xor-then-multiply produces on small/adjacent group keys.

Mix a Double into the accumulator. Loses sub-millisecond precision but matches the bucketing the old hashable-based code used.

Mix a Text value into the accumulator over its raw UTF-8 bytes, eight at a time. Reading a whole Word64 per step cuts the multiply count ~8x on long keys while staying collision-equivalent (UTF-8 is injective).

Mix a raw UTF-8 byte slice [off, off+len) of a Array into the accumulator, eight bytes at a time. The shared kernel behind mixText and the packed-text hash path, so the two never drift.

Fallback for arbitrary Show-able values. Slower but covers types without a dedicated combinator (e.g. Day, UTCTime).