Build close to the metal. Keep intent in view.

v0.1.2Latest tagged release

Native targetsLLVM-backed compilation

Early stageAPIs and syntax can still evolve

Testable by design

Generics, modules, and assertions in one native workflow.

Flecha tests are ordinary typed code with first-class test declarations. Import reusable modules, exercise generic algorithms over slices, and verify results with the standard assertion library.

Run the suite with flecha test and get the same compiler checks as production code.

algorithms_test.fl

module algorithms_test;

@imports
    :: root::containers::algorithms
    :: lib::std::tests::testing
    :: lib::std::tests::asserts;

test index_of_finds_the_first_match(&testing::UnitTest t) {
    [5]i32 values = [10, 20, 30, 20, 40];

    index, found := algorithms::index_of<i32>(values[:], 20);
    asserts::is_true(t, found, "index_of finds a present value");

    usize expected = 1;
    asserts::equal<usize>(
        t, &expected, &index, "index_of returns the first match"
    );
}

Built for clarity

Direct control, backed by compiler checks.

&T

Explicit memory

Checked references, slices, raw allocation in unsafe code, ownership contracts, and definite-assignment analysis.

!?

Strong diagnostics

A tokenizer, parser, semantic analyzer, and lowering pipeline designed to surface source-level problems clearly.

→

Native by default

Emit LLVM IR, objects, or host-native executables. The runtime and standard library ship with release archives.

Choose a path

From first build to language internals.

Start with a working compiler, learn the core syntax, then go as deep as the implementation notes and specification.

InstallBuild from source and verify the toolchain.LearnWrite, check, and compile your first Flecha program.DocsExplore language features, tooling, ABI, and design notes.ExamplesBrowse runnable programs synced from the compiler repo.