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.