This is a set of tools for automated counting of STV elections. At present, it reads in BLT files and validates them. Ultimately it will implement the ERS97 dialect of the Single Transferable Vote voting system.
It is intended that there will be at least three implementations of STV in this project:
-
a reference implementation, designed to be simple and easier to verify as being correct; this is written in idiomatic OCaml, without the use of variables, mutable data structures, and with clearly documented and enforced invariants
-
two conventional-language implementations, structured analogously to the reference implementation and intended to be bug-for-bug compatible with it, in necessarily slightly unidiomatic Python and Java, for inspection by a broader community of users
There will also be a test suite, particularly of BLT files.
It is assumed that BLT input files may be inadvertently or deliberately malformed, and that this should be detected rather than triggering unexpected or exploitable behaviour directed against the election being counted or against the machine being used to do so.
- BLT files (link todo)
These instructions assume a pre-installed OCaml system with various build-time dependencies already available; instructions for establishing this will be provided later.
Having checked out this repository, do:
$ (cd reference && oasis setup && ocaml setup.ml -configure && ocaml setup.ml -build)
$ reference/test_stv.byte --dir test_data
$ reference/main.byte < test_data/example.blt
The reference implementation avoids all advanced features of the OCaml language, but does employ some terse abbreviated syntax where idiomatic. Programmers with three or four months' OCaml experience should have no trouble following the code.