stone

a small, general-purpose language for clarity, correctness, and performance

written clear.written secure.written in stone.

What It Looks Like

Clean syntax, no boilerplate. The compiler resolves types, manages memory, and optimises aggressively.

Functions and Values

name = "Alice"
items = [1, 2, 3, 4, 5]

fn square(x) = x * x
fn greet(name) = "Hello, " + name

Indexed Mapping

xs = [1, 2, 3, 4]
doubled[i] = xs[i] * 2
// doubled is [2, 4, 6, 8]

// each iteration is independent —
// the compiler can parallelise this

Structured Iteration

sum, count := evolve {sum = 0, count = 0} for (x in xs) {
  sum' = sum + x
  count' = count + 1
}
mean = sum / count

Records and Functions

point = {x = 3.0, y = 4.0}
dist = sqrt(point.x ^ 2 + point.y ^ 2)

fn magnitude(p) = sqrt(p.x ^ 2 + p.y ^ 2)

Design Principles

Stone is a functional language — programs are systems of values, not sequences of side effects.

Expression-Oriented

Every construct produces a value. You compose expressions into results, then direct them to an output.

Immutable by Default

Values cannot be changed after creation. State transitions are explicit declarations through evolve loops.

Static Type Resolution

Full static type safety without the verbosity — everything is resolved at compile time and type annotations are optional.

Structured Iteration

Evolve loops declare their state, update rules, and exit conditions. The compiler sees the full structure at a glance.

No Null, No Exceptions

Functions always return a value of their declared type. No null checks, no exception tables, no surprises.

Performance

Because Stone values don't change, the compiler can safely reorder work, combine loops, process arrays in parallel, and lay out data efficiently in memory. The result is C-level performance from high-level code.

0.95x

of C across 17 benchmarks

1.7x

of C, running in the browser

100M→ 1

iterations replaced by formula

See the full benchmarks or read how Stone is fast.