lean4/tests/compiler/foreign/README.md

Small project implemented using Lean and C++. The C++ file myfuns.cpp wraps a C++ object using an lean_external_object. The file myfuns.cpp exposes pure and effectful primitives. The file Main.lean contains a small Lean program that uses the exported primitives.

Build instructions

Assuming the Lean bin/ directory (e.g. from build/release/stage1) is in your PATH, executing leanmake build/bin/test will create the executable build/bin/test; see the Makefile for further variants.

The executable build/bin/test should produce the output

30
hello
foobla
world