Jasper

Jasper is a scripting language inspired by Haskell, Javascript, and modern C++. Jasper can be embedded in C++ applications.

The aim of Jasper is to be:

• Nice to use
• Easy to refactor
• Consistent

For this purpose, Jasper has:

• Sum types
• Record types
• Type deduction
• First class functions with closure
• Consistent and context-free syntax
• Syntactic sugar
• Many others

Here is an example piece of "functional-style" code:

fn greeting(name) =>
    "Hello, "
    + (if (name == "")
        then "friend"
        else name)
    + "!";

It can also be written like this, in a more imperative style, and using some intermediate variables:

fn greeting(name) {
    if (name == "")
        name = "friend";
    prefix := "Hello, ";
    suffix := "!";
    return prefix + name + suffix;
};

or like this, mixing functional, and imperative style:

fn greeting(name) =>
    seq {
        if (name == "")
            return "friend";
        return name;
    }
    |> (fn(name) => "Hello, " + name + "!")();

you can find more examples in the tests directory.

Using the interpreter

First, you have to compile it using the following command:

make interpreter

Once it is compiled, you can find the executable under bin/jasperi, and execute it following the user guide, which can be found in multiple languages in the docs directory.

NOTES: Our Makefile uses non-standard features of gnu make

Jasper is written in C++14, so you will need a C++14 compatible compiler, such as GCC 6.1 or later

Running the tests

We also have small test suite, which can be compiled with

make tests

and then run with

./bin/run_tests