Tests

dune build @all @runtest

Suite

• Every spec vector, and long stream dumps from the Julia implementation.
• The conformance files of the spec, byte copies in test/conformance, read by test/conformance.ml, which demonstrates every item of the spec's conformance/CHECKLIST.md at 2a4bd08 that the port offers. Every case of the bounded, normal, exponential and weighted choice files runs through the C fills, Tandem.Pure, both array kinds, the scalar draws and Tandem.State, and cut at elements 1, 7, 20, 21 and n - 1, bit for bit with its end position. The checks cover the choice tables, the global draw index of the fallback, the width from the range, empty fills, rejected weights, the choice law, random access, the position bounds, and the SHA-256 and FNV-1a of the streams and the Float64 normal dumps in hashes.json. OCaml has no single precision float, so the Float32 cases and the Float32, Bool, 128-bit, Char, binary16 and UInt8 streams are counted and left out, and the fill-end check of section 5 cannot be reached with an array that fits in memory.
• Fills against scalar draws, cut fills, empty fills. Normal fills are cut on and around elements that take the ziggurat's fallback stream.
• C fills against Tandem.Pure, bit for bit.
• The hash of the Float64 part of 5 * 10^6 exponentials from tandem-c, for both paths. Moments to the fourth order and Kolmogorov-Smirnov tests on 10^7 normals from each path and on 10^7 exponentials.

dune build @all @runtest runs four suites: vectors (every spec vector), streams (Julia dumps as fills and scalar draws), conformance and derived (everything else above).

Fixtures

test/conformance/*.json are byte copies of tandem-spec 2a4bd08 conformance/*.json, and CI compares them with the spec. python3 tools/gen_vectors.py ../tandem-spec/vectors.json > test/vectors_data.ml converts the spec vectors. The f64 part of tandem-c's tools/dump_exponentials.c hashes to 0x8cb6728a73181814, and the full dump to 0x1c761a2d471073c2 as tandem-c records.

CI

CI runs opam exec -- dune build @all @runtest on ubuntu-latest and macos-latest with OCaml 5.5 and 5.4.