tallyman
tallyman is a work-in-progress rust library for tallying votes.
Current state is very unstable. It is not currently recommended for use. See checkboxes below for a list of features that are complete.
Goals
- Ergonomic - Easy to use.
- Fast - Be the fastest general-purpose vote tallying library in the world.
- Secure - Have no undefined behavior.
- Complete - Support all well-known voting methods.
- Deterministic - Running the same tally twice should never produce different results.
- Generic - Generic over both candidate and count types.
Features
-
no_stdfor embedded use. -
wasmsupport for use in the browser, or in blockchain smart contracts. -
rationalsupport for perfectly-precise tallies by using rational fractions instead of floats.
Supported Tally Methods
| Status¹ | Tally Method | Supported Variants | Performance² | Notes |
|---|---|---|---|---|
| ✓ | Plurality | 100 million v/s | First Past the Post (FPTP) | |
| ⚠ | Score | |||
| ⚠ | Approval | |||
| ⚠ | STV | Newland-Britton, Meek, Warren | 3 million v/s | Single Transferable Vote |
| CPO-STV | ||||
| Instant Runoff | ||||
| Contingent | ||||
| ⚠ | Condorcet | 2 million v/s | ||
| Copeland | ||||
| Schulze | Winning, Margin, Ratio | |||
| Schulze STV | ||||
| Kemeny–Young | ||||
| Minimax | ||||
| ✓ | Borda | Classic, Dowdall, Modified | 3 million v/s | |
| Borda - Nanson | Classic, Dowdall, Modified | |||
| Borda - Baldwin | Classic, Dowdall, Modified | |||
| Dodgson | Quick, Tideman | |||
| Ranked pairs | Margin, Winning | |||
| STAR | ||||
| Majority judgment | ||||
| D'Hondt | Sainte-Laguë, Huntington-Hill, Quota |
- ✓ means done, ⚠ means in-progress, blank means not started but support is planned.
- Single threaded performance measured in votes tallied per second. Benchmarked on a 2017 Macbook Pro.