seq-marked

Sequence-numbered values with tombstone support for LSM trees and versioned data.

Core Types

Marked<D>: Data that can be marked as tombstone
SeqMarked<D>: Sequence-numbered marked value

Usage

use seq_marked::{Marked, SeqMarked};

// Basic sequence-numbered values
let v1 = SeqMarked::new_normal(1, "data");
let v2 = SeqMarked::new_normal(2, "data");
let v2_ts = SeqMarked::<&str>::new_tombstone(2);

assert!(v1 < v2); // ordered by sequence
assert!(v2 < v2_ts); // tombstone > normal

// Working with marked values
let data = Marked::Normal("hello");
let tombstone = Marked::<&str>::TombStone;
assert!(tombstone > data);

// Accessing data
assert_eq!(v1.data_ref(), Some(&"data"));
assert_eq!(v2_ts.data_ref(), None);
assert!(v2_ts.is_tombstone());

// Transform data while preserving sequence
let lengths = v1.map(|s| s.len());
assert_eq!(lengths.data_ref(), Some(&4));

API Overview

`Marked<D>`

Normal(D) - contains data
TombStone - deletion marker
Tombstones are always ordered after normal values

`SeqMarked<D>`

new_normal(seq, data) - create normal value
new_tombstone(seq) - create tombstone
seq() - get sequence number
data_ref() / into_data() - access data
is_normal() / is_tombstone() - check type
map(fn) - transform data while preserving sequence
order_key() - get ordering key without data

Features

Sequence-based ordering with tombstone support
Optional serde/bincode serialization
Comprehensive ordering semantics for LSM trees

License

Apache License 2.0 - see LICENSE file for details.

Contributing

Contributions welcome! Please ensure all tests pass and code is properly formatted before submitting a PR.

seq-marked 0.3.0