DEXA language overview

[ GETTING STARTED ]#

1. git clone https://github.com/dxiv/dxa-dev
2. cd compiler
3. cargo run -- ../examples/hello.dxa

fn add(a: int, b: int) -> int {
    return a + b;
}
fn main() { let three: int = add(1, 2); return; }

[ SYNTAX ]#

Functions with fn; statements: let, return, if/else, loops. Types: int, float, bool, string, unit, address. Explicit address("...") — no implicit coercions.

[ TYPES ]#

int, float, bool, string, unit, address, Record<Name>. No implicit coercions; address("...") builtin.

[ RECORDS ]#

model / contract. Record literals; update syntax Type { ..base; field: expr }. Base must match type.

model Wallet {
    owner: address;
    balance: int;
}

[ FUNCTIONS & CONTROL ]#

fn with typed params; return optional. let / let mut; if/else, while, loop, break, continue.

[ BUILTINS ]#

print(expr), address(string), require(cond, msg?). Math: abs(x), min(a,b), max(a,b), sqrt(x) (float). len(s) → int. On false → ProgramResult::RequireFail.

fn main() -> int {
    require(abs(-7) == 7, "abs");
    require(min(1, 2) == 1 && max(1, 2) == 2, "min/max");
    require(sqrt(4.0) == 2.0, "sqrt");
    require(len("hello") == 5, "len");
    return 0;
}

[ EXECUTION ]#

Source → tokens → AST → typecheck → lower → DX-IR → IR validation → interpret. ProgramResult::Ok { value, prints, trace, gas } or RequireFail.

Running main yields value, prints, trace, gas. require(cond, msg?) → RequireFail on false.

[ DETERMINISM & GAS ]#

DEXA aims for deterministic execution: the same source, inputs, and gas limit always produce the same result, trace, and gas usage. No hidden IO, syscalls, or ambient state.

The interpreter tracks a logical gasSteps counter: each evaluated expression, branch, and loop iteration consumes gas. When gas is exhausted, evaluation halts safely instead of diverging.

The execution trace records the high-level steps the program took (calls, requires, branches). Together, trace + gas make runs auditable and bound in cost, even before specialised backends exist.

[ ROADMAP ]#

Now: Lexer, parser, functions, blocks, if/else, loops, let/let mut, typechecker, DX-IR, interpreter, IR validation.

Next: Diagnostics, arrays/slices, CLI JSON, minimal stdlib.

Later: Tensor types & GPU, contract subset & DX-VM.