Cocodol

Cocodol is a simplistic (to not say dumb) programming language, designed to illustrate how to build a small interpreter/compiler. Cocodol support a very small set of features, namely unbounded loops, higher-order functions and a handful of built-in data types.

The core of the compiler is written in C. This includes the parser, basic static analysis and a (relatively slow) interpreter, built as an AST walker. Code generation and tests are written in Swift.

Example

The following example implements the factorial function and applies it to an argument:

fun factorial(n) {
  if (n > 1) {
    ret n * factorial(n - 1)
  } else {
    ret 1
  }
}

print(6)
// Prints 720

See the Examples folder for more program examples.

Installation

Cocodol's compiler is written in Swift and distributed in the form of a package, which can be built with Swift Package Manager.

You will also need to install LLVM. Use your favorite package manager (e.g., port on macOS or apt on Ubuntu) and make sure llvm-config is in your PATH. Then, create a pkgconfig file for your specific installation. The maintainers of LLVMSwift were kind enough to provide a script:

swift package resolve
swift .build/checkouts/LLVMSwift/utils/make-pkgconfig.swift

On Ubuntu, you will also need libc++ to link your code with LLVM:
apt-get install libc++-dev
apt-get install libc++abi-dev

You can then build and install Cocodoc's compiler using the install.sh script, at the root of the repository. The build should take a couple of minutes:

./install.sh
cocodoc Examples/Inc.cocodol
./Inc
# Prints 1048575

By default, the compiler's binary (i.e., cocodoc) is installed at /usr/local/bin and the language's runtime library at /usr/local/lib. You can change both of these locations at the top of the script. Alternatively, you can also build the compiler and the runtime library manually:

swift build -c release
# Creates .build/release/cocodoc
cd Runtime && make
# Creates Runtime/build/libcocodol_rt.a

Compiling the C interpreter

You can run the walker interpreter by executing cocodoc with the --eval flag. Alternatively, you can also compile the interpreter as a standalone application. Its sources are contained in Sources/CCocodol. To compile them, navigate to this directory and run make:

cd Sources/CCocodol
make

This will produce an executable named cocodol in Sources/CCocodol/build. It takes the path to a Cocodol program as its sole argument:

cocodol Examples/Inc.cocodol
// Prints 1048575

License

Cocodol and its compiler are licensed under the MIT License.