The Rea front end for the PSCAL VM, and the shared front-end engine that Aether is built on. Rea parses its source into the shared PSCAL AST, which the shared bytecode compiler lowers and the PSCAL VM runs.

Rea carries no VM or code generator of its own. It builds against pscal-core, pulled in automatically via CMake FetchContent.

These sources double as the shared engine for both Rea and Aether. The engine talks to "its" front end only through a small hook interface (src/rea/frontend_hooks.h): the engine calls reaFrontend*() accessors that default to Rea's built-in behaviour, and a front end such as Aether installs its overrides (parse, semantic analysis, diagnostics, ...) at startup via reaSetFrontendHooks(). As a result the engine has no compile- or link-time dependency on any specific front end.

cmake -S . -B build      # fetches and builds pscal-core, then rea
cmake --build build -j
./build/rea --no-cache program.rea

cmake --install build --prefix /usr/local

This puts the rea binary in <prefix>/bin, the example programs in <prefix>/share/rea/examples, and the language docs in <prefix>/share/doc/rea. The fetched pscal-core also installs its static library and headers under the same prefix.

The .rea conformance corpus lives in tests/ and runs under CTest:

ctest --test-dir build --output-on-failure

You can also run it directly against any binary by pointing REA_BIN at it (this is how the umbrella build exercises the same corpus):

REA_BIN=./build/rea tests/run.sh

Fixtures that need an optional capability are skipped automatically when the binary lacks it: the SQLite fixture skips when the sqlite ext-builtins are not compiled in, and the 3D demo fixtures skip when the 3d ext-builtins are absent. A minimal standalone build (SDL, curl, and SQLite OFF by default) therefore stays green.

Runnable programs live in examples/, from base/hello through the object-oriented base/showcase and base/hangman5 demos:

./build/rea --no-cache examples/base/hello
./build/rea --no-cache examples/base/showcase

The examples/sdl/ programs need a graphics-enabled build.

In-depth language documentation is in docs/:

• rea_overview.md: a short tour of the language
• rea_tutorial.md: a worked introduction
• rea_programmers_guide.md: the full guide
• rea_language_reference.md: the reference

See src/rea/LANGUAGE_SPEC.md for the language specification and src/rea/README.md for the front-end internals.