Decision Workspace
par vs promisery vs a3s-lane
Side-by-side comparison of Rust crates
40
par
growingv0.3.10
Session types, as an implementation of linear logic with MIX
56
promisery
growingv2.0.1
A JavaScript-inspired, ergonomic, and composable Promise type for Rust, supporting background work, chaining, and error handling with Result.
56
a3s-lane
experimentalv0.4.0
Lane-based priority command queue for async task scheduling with reliability, scalability, and observability features
Core Metrics
| par | promisery | a3s-lane | |
|---|---|---|---|
| Health Score | 40 | 56 | 56 |
| Total Downloads | 14.8K | 2.1K | 2.6K |
| 30d Downloads | 0 | 0 | 0 |
| Dependents | 0 | 1 | 49 |
| Releases | 16 | 5 | 7 |
| Last Updated | 306d ago | 325d ago | 96d ago |
| Age | 1y 7m | 10m | 3m |
Health Breakdown
par
Maintenance
9
Quality
10
Community
6
Popularity
5
Documentation
10
promisery
Maintenance
14
Quality
18
Community
7
Popularity
4
Documentation
13
a3s-lane
Maintenance
14
Quality
14
Community
11
Popularity
4
Documentation
13
Technical Details
| par | promisery | a3s-lane | |
|---|---|---|---|
| Version | 0.3.10 | 2.0.1 | 0.4.0 |
| Stable (≥1.0) | ✗ No | ✓ Yes | ✗ No |
| License | MIT | MIT OR Apache-2.0 | MIT |
| Dependencies | 4 | 2 | 19 |
| Crate Size | 31KB | 9KB | 78KB |
| Features | 3 | 0 | 5 |
| Yanked % | 75.0% | 0.0% | 0.0% |
| Edition | 2021 | 2021 | 2021 |
| MSRV | — | — | — |
| Owners | 1 | 1 | 1 |
Links
Quick Verdict
- •promisery leads with a health score of 56/100, but none of the options score above 80.
- •par has the most downloads (14.8K), suggesting wider adoption.
- •par, a3s-lane are pre-1.0 — API may change.