Decision Workspace
par vs promisery vs a3s-lane
Side-by-side comparison of Rust crates
41
par
growingv0.3.10
Session types, as an implementation of linear logic with MIX
57
promisery
growingv2.0.1
A JavaScript-inspired, ergonomic, and composable Promise type for Rust, supporting background work, chaining, and error handling with Result.
52
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 | 41 | 57 | 52 |
| Total Downloads | 14.8K | 2.1K | 1.6K |
| 30d Downloads | 33 | 24 | 942 |
| Dependents | 0 | 1 | 23 |
| Releases | 16 | 5 | 7 |
| Last Updated | 247d ago | 266d ago | 37d ago |
| Age | 1y 6m | 8m | 1m |
Health Breakdown
par
Maintenance
10
Quality
10
Community
6
Popularity
5
Documentation
10
promisery
Maintenance
15
Quality
18
Community
7
Popularity
4
Documentation
13
a3s-lane
Maintenance
11
Quality
14
Community
10
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 57/100, 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.