mbeckem / tiro

A simple scripting language.

Tiro

Website

Documentation and sandbox: https://mbeckem.github.io/tiro-website/.

Introduction

Tiro is a young dynamic programming language with a runtime designed to be easily embeddable into other applications.

A snippet of tiro looks like this:

import std;

func main() {
    const object = "World";
    std.print("Hello ${object}!");
}

Or like this:

func fibonacci(i) {
    if i <= 1 {
        return i;
    }

    var a = 0;
    var b = 1;
    while i >= 2 {
        (a, b) = (b, a + b);
        i -= 1;
    }
    return b;
}

Or like this:

import std;

func fizzbuzz() {
    for var i = 1; i <= 100; i += 1 {
        const message = if i % 15 == 0 {
            "FizzBuzz";
        } else if i % 3 == 0 {
            "Fizz";
        } else if i % 5 == 0 {
            "Buzz";
        } else {
            "$i";
        };

        std.print(message);
    }
}

The Language

Design Goals and Rationale

• Readability. Syntax and semantics should feel familiar or easy to learn.
• Expressiveness. The language should not require excessive amounts of boilerplate code.
• Variables should have dynamic types for quick prototyping and for easier interfacing with the host application.
• Support for more rigid constructs like classes and modules to structure larger code bases.
• Async execution model by default (with cheap coroutines / lightweight threads) to support common scripting tasks in domains like network services or games.
• Acceptable performance at runtime. The implementation should not be slower than that of comparable languages.
• The option to implement components in native code gives developers the ability to interface with the system, to reuse existing native libraries and to implement high performance parts of their application in a compiled language.
• Easily embeddable and extensible runtime library with a simple C-API and a small size footprint to support as many platforms as possible.
  The runtime should be a "good citizen" in its embedding context: global state is forbidden and runtime instances are isolated from each other.

Non-Goals

• Maximum performance is not a requirement.
• Highly experimental or unproven language constructs will not be implemented. This is not a research project - the language's feature set is rather conservative.

Code examples

Have a look at the examples directory and the unit tests.

Quick start

1. Prerequisites:

   • A C++17 compiler
   • CMake >= 3.13

2. From inside the project directory, run:

   $ mkdir build && cd build
   $ cmake .. -DTIRO_TESTS=1     # -DCMAKE_BUILD_TYPE=Debug -DTIRO_WARNINGS -DTIRO_WERROR for development
   $ cmake --build . -j $(nproc) # Use -j N for parallel builds
   $ ./bin/unit_tests && ./bin/api_tests
   $ ./bin/tiro_run ../examples/fizzbuzz/fizzbuzz.tro --dump-ast --disassemble --invoke fizzbuzz
   

For more detailed build instructions, read building.md.

Repository overview

Project repository

.
├── docs                -- Design documents and notes
├── examples            -- Code examples
├── include             -- Public C API
├── scratch             -- Test code (TODO: Remove)
├── src                 -- Implementation of cli tools, API, compiler and vm
├── support             -- Utility files (like codegen scripts, unicode database, cmake support scripts)
└── test                -- Automated tests

Source code folder overview

src
├── api                 -- Implementation of the public interface (i.e. include/tiro)
├── bytecode            -- Defines bytecode objects (output of the compiler, input of the VM)
├── common              -- Reuseable types, macros and functions used by the compiler or the vm
├── compiler            -- Implementation of the compiler
│   ├── ast             -- Defines all AST types and associated helpers (e.g. tree traversal)
│   ├── ast_gen         -- Implements the syntax tree -> abstract syntax tree transformation
│   ├── bytecode_gen    -- Transforms the internal representation into executable bytecode
│   ├── ir              -- Defines the internal representations
│   ├── ir_gen          -- Transforms the AST into the internal representation
│   ├── ir_passes       -- Optimization and analysis of the internal representation
│   ├── semantics       -- Semantic analysis passes during compilation
│   └── syntax          -- Source code parser and grammar implementation
├── run                 -- Implementation of cli tools
└── vm                  -- Implementation of the virtual machine
    ├── builtins        -- Importable default modules (e.g. "import std")
    ├── handles         -- Handle types for referencing objects on the managed heap
    ├── heap            -- Garbage collected heap implementation
    ├── modules         -- Implementation of the module system
    └── objects         -- VM Object types (e.g. Arrays, HashTable, Strings, ...)

Dependencies

These dependencies are fetched during the build and will be included (statically linked) when tiro is built as a library.

• Abseil
  Website: https://abseil.io/
  License: Apache-2.0 License

• {fmt}
  Website: https://fmt.dev/latest/index.html
  License: Link

• Utfcpp
  Website: https://github.com/nemtrif/utfcpp
  License: Boost Software License 1.0

• nlohmann/json
  Website: https://github.com/nlohmann/json
  License: MIT License

Test Dependencies

Not included in the final executable library:

• Catch2
  Website: https://github.com/catchorg/Catch2
  License: Boost Software License 1.0