SiS (SiS interprets Scripts)

SiS is a lightweight scripting language with a C-like syntax, first-class functions, classes, and an extremely minimal standard library of C++ native extensions.

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Quick Look

include "math";
include "string" as str;

class Shape {
    pin name = "shape";

    fn constructor(name) {
        this->name = name;
    }

    fn describe() {
        return str.format("I am a {}", this->name);
    }
}

class Circle extends Shape {
    pin radius = 0;

    fn constructor(r) {
        super->constructor("circle");
        this->radius = r;
    }

    fn area() {
        return math.PI * math.pow(this->radius, 2);
    }
}

pin c = new Circle(5);
print(c.describe());         // I am a circle
print(math.round(c.area())); // 79

For the full language reference, see docs/LangSyntax.md.

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Building

Using the provided install scripts in releases is recommended. But you can also build from source. SiS requires CMake. The build assumes a Linux or Unix environment. Windows cross-compilation is supported via MinGW. See docs/Building.md for more information.

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Running a Script

sis my_script.sis

Set $SIS_PATH to the directory where SiS is installed. The interpreter looks for standard libraries under $SIS_PATH/lib/managed or $SIS_PATH/lib/dynamic.

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Standard Library

Import libraries with include. Omit the file extension for standard library modules.

include "math";
print(math.sqrt(144)); // 12

Library	Description
io	File and directory I/O
math	Math functions and constants
os	Environment, shell, process control
random	Random number and array utilities
regex	Regular expression matching
string	String manipulation
time	Timestamps, sleep, and DateTime

Full documentation for each library is in docs/stdlib/.

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Extending SiS

SiS loads native extensions from shared libraries (.so / .dll). Write your extension in C++, implement sis_module_init, and drop the compiled library into $SIS_PATH/lib/dynamic/.

#include <SisDynamicLibMacros.h>

FN_SIGNATURE(fnAdd, args) {
    double a = requireNum(args[0], "add");
    double b = requireNum(args[1], "add");
    return {a + b};
}

SIS_MODULE_INIT(reg) {
    reg->defineFn("add", fnAdd, "@brief Adds two numbers.");
}

g++ -std=c++23 -shared -fPIC \
    -I/path/to/sis/include \
    mylib.cpp \
    -o $SIS_PATH/lib/dynamic/mylib.so

include "mylib";
print(mylib.add(1, 2)); // 3

See docs/LibraryCreation.md for the full API and docs/Building.md for build options.

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TODO

• Make LSP server
• Add example project