Talos v0.2.0

Installing Talos

curl -fsSL https://talos.rroessler.io/install.sh | bash

Upgrading Talos

talos upgrade

Runtime Updates

As the past few months of work comes to pass, various wide-sweeping updates have been applied to the Talos runtime. Looking back at the initial progress report in May, only tasks related to testing are still to be addressed. Without further ado, here are the newest features to Talos:

Match Statements

This release introduces the foundations for the match statement, which evaluates an expression and matches it to a selection of given guards.

// Suppose that `value` could be the `String` type.
match (value) {
    "a": Debug.println("First latin character"),
    "z": Debug.println("Last latin character"),
    *: Debug.println("Some other character"),
}

If value contained the letter "z" it would then print "Last latin character" then continue execution after the match statement. Unlike other languages, cases do not fall-through to the next after completion and should be treated as separate. However, multiple guards can be grouped together:

match (value) {
    "a", "A": Debug.println("Found letter 'a'"),
    *: Debug.println("Value was not the letter 'a' or 'A'"),
}

Values can also be matched against their builtin classes as type-guards.

match (value) {
    String: Debug.println("Value was a string"),
    Number: Debug.println("Value was a number"),
    *: Debug.println("Did not match a valid type"),
}

However, some care should be taken with this as match statements attempt their matches greedily from top-to-bottom.

match (True) {
    Boolean: Debug.println("Value is a boolean"), // Matched first in declaration order
    True: Debug.println("Value is boolean true"), // Ignored when declared after above guard
}

Faster Functions

Along with updating the runtime, an opt-in attribute was added to allow compilation to machine-code for faster performance.

// This function will be compiled to an equivalent version of the `ret Number(42)` shorthand.
#[Internal.Optimize]
let foo = fn => 42;

This has been made opt-in as compilation to machine-code will take up more memory than that of regular bytecode functions, so care should be taken when applying this attribute. The core reasoning for exposing this feature is for the future work to the builtin crates which will allow improving the performance of critical code sections.

Upcoming Work

Following on from this release will be the improvements to testing. This next goal is to improve the currently available testing to ensure stability before releases. It will also hopefully include the foundations for more builtin crates for Talos.

Bug Fixes

Package / talos

• Fixed: Updated the current CI infrastructure to now be independent of a release script.
• Fixed: Stablized naming for all releases and artifacts. Now using v{semver}-{branch} format.
• Fixed: CMake infrastructure had some minor modifications made to improve compile-times.
• Fixed: All crates for Talos have been reworked to now feature documentation friendly comments.

Package / website

• Moved: All content for the website can now be found in the /docs folder of the monorepo.
• Fixed: Headings for the builtins and crates sections are now constructed dynamically.

Package / vscode

• Added: Allow users to install Talos when the executable cannot be found.
• Fixed: Restarting the language server now does not error if it had not already been started.

Toolkit / talos run

• Fixed: The equality operator == was ill-formed for String values. Now these compare values correctly.
• Added: Implemented constant load propagation to further optimize bytecode. This effectively speeds up variable loads.
• Moved: Changed typing of Function.bind to be a static field for Function instead of an instance field.
• Fixed: Improved the internal AST design to use lexical tokens to describe ranges/bounds for source code.
• Moved: The bytecode interpreter now uses tail-calls instead of direct-threading with goto* statements.
• Added: Fully completed a baseline JIT compiler. This is now exposed via the
• Added: Implemented the match statement as described in this blog-post. For now it is just a basic implementation.

Crate / talos:jit

• Moved: The JIT compilation library was removed in lieu of the #[Internal.Optimize] attribute.

Crate / talos:lint

• Added: Prepare the stub-definitions for the talos:lint crate. This will be for eventual linting plugins.