Build a compiled .so and create a Python binding

.github/workflows/python-wheel.yml

@@ -0,0 +1,16 @@
+# Pin the `@main` ref to a JuliaLibWrapping release tag once one containing
+# build-wrappers.yml exists.
+name: Python wheel
+on:
+  release:
+    types: [published]
+  workflow_dispatch:
+permissions:
+  contents: write
+jobs:
+  wheel:
+    uses: JuliaInterop/JuliaLibWrapping.jl/.github/workflows/build-wrappers.yml@main
+    with:
+      build-dir: lib
+      cpu-target: "generic;sandybridge,-xsaveopt,clone_all;haswell,-rdrnd,base(1)"
+      smoke-test: lib/test/python/test_smoke.py

.gitignore

@@ -6,3 +6,6 @@
 /docs/Manifest*.toml
 /docs/build/
 /test/generator/Manifest*.toml
+/lib/out/
+/lib/Manifest.toml
+/lib/build-env/Manifest.toml

README.md

@@ -74,3 +74,28 @@ true
 
 See the [documentation](https://HolyLab.github.io/MatrixCovers.jl/dev/)
 for motivation, examples, and a full API reference.
+
+## Python
+
+A subset of MatrixCovers is available as a compiled Python package that does
+not require Julia. Install a wheel from a
+[GitHub release](https://github.com/HolyLab/MatrixCovers.jl/releases):
+
+```
+pip install https://github.com/HolyLab/MatrixCovers.jl/releases/download/vX.Y.Z/matrixcovers-X.Y.Z-py3-none-manylinux_2_35_x86_64.whl
+```
+
+Replace `X.Y.Z` with a released version. Wheels support Linux x86_64 with
+glibc >= 2.35 (Ubuntu 22.04+,
+Debian 12+, Fedora 36+; not RHEL/Rocky 9).
+
+```python
+import numpy as np
+import matrixcovers as mc
+
+A = np.array([[4.0, 2.0], [2.0, 16.0]])
+a = mc.symcover(A)          # a[i] * a[j] >= abs(A[i, j])
+print(mc.iscover(a, A))     # True
+```
+
+See `lib/python/_facade.py` for the Python API.

lib/Project.toml

@@ -0,0 +1,15 @@
+name = "matrixcovers"
+uuid = "9a0ce11c-0abe-4c5a-899b-d53d9853b6d8"
+version = "0.0.1"
+
+[deps]
+JLWInterop = "65e54657-ed21-41a3-96db-71ab7fa6d94b"
+MatrixCovers = "727e6139-ff52-4636-a344-ed1d23e73ffc"
+Random = "9a3f8284-a2c9-5f02-9a11-845980a1fd5c"
+
+# `build.jl` adds the local MatrixCovers source to a temporary copy.
+
+[compat]
+JLWInterop = "0.1"
+MatrixCovers = "1"
+julia = "1.13"

lib/build-env/Project.toml

@@ -0,0 +1,13 @@
+# Build dependencies for the matrixcovers Python wheel. The runtime
+# dependencies are defined in `../Project.toml`.
+#
+#     julia +rc --project=lib/build-env -e 'using Pkg; Pkg.instantiate()'
+
+[deps]
+JuliaC = "acedd4c2-ced6-4a15-accc-2607eb759ba2"
+JuliaLibWrapping = "d61f35a8-f6af-436f-bc10-cee6b101f7bd"
+
+[compat]
+JuliaC = "0.3"
+JuliaLibWrapping = "0.1.2"
+julia = "1.13"

lib/build.jl

@@ -0,0 +1,45 @@
+# Build the Python wheel from the repository root with Julia 1.13:
+#
+#   julia +rc --project=lib/build-env lib/build.jl
+#
+# Instantiate the build environment first:
+#
+#   julia +rc --project=lib/build-env -e 'using Pkg; Pkg.instantiate()'
+#
+# The temporary project supplies the absolute source path required by juliac.
+
+using TOML: TOML
+
+const HERE = @__DIR__
+const REPO_ROOT = abspath(joinpath(HERE, ".."))
+
+function prepare_project()
+    toml = TOML.parsefile(joinpath(HERE, "Project.toml"))
+    sources = get(toml, "sources", Dict{String, Any}())
+    sources["MatrixCovers"] = Dict("path" => REPO_ROOT)
+    toml["sources"] = sources
+    tmp = mktempdir(; prefix = "matrixcovers-lib-project-")
+    open(joinpath(tmp, "Project.toml"), "w") do io
+        TOML.print(io, toml; sorted = true)
+    end
+    return tmp
+end
+
+const REPO_VERSION = TOML.parsefile(joinpath(REPO_ROOT, "Project.toml"))["version"]
+
+using JuliaLibWrapping, JuliaC
+
+result = standard_build(HERE;
+    libname = "matrixcovers",
+    python_package = "matrixcovers",
+    project = prepare_project(),
+    version = REPO_VERSION,
+    verbose = true,
+)
+
+# Replace the generated facade with the public API.
+cp(joinpath(HERE, "python", "_facade.py"),
+   joinpath(HERE, "out", "matrixcovers", "_facade.py");
+   force = true)
+
+@info "Built matrixcovers" library=result.library bundle=result.bundle_dir