Spore (孢子)

A general-purpose programming language optimized for Agent-human intent interaction.

Spore is a compiled language where function signatures are "gravity centers" — complete specifications carrying type, error, required effect, and cost information. The compiler serves as a documentation assistant, and the hole system enables Agent-driven collaborative development.

Key Features

• Hole System: ?name partial functions as first-class collaboration protocol with Agents
• Effect System: IO effects gated by required effects, verified at compile time
• Cost Model: 4-dimension cost analysis (compute, alloc, io, parallel) with compile-time budgets
• Content-Addressed: Dual hash (sig + impl) for modules — no semver, pure hash addressing
• Effect Handlers: All IO through Platform-provided effect handlers, application code stays pure
• Structured Concurrency: Task trees with cancellation propagation, channels for communication
• Expression-Based: Everything is an expression, no loops (recursion + higher-order functions)

Canonical Surface Syntax

• Modules come only from file paths; there is no module ... header.
• Effect checks live on function signatures and package/Platform boundaries only; source files have no module-level uses carrier.
• Stable generic bounds use a single comma-separated clause: where T: Trait, U: Trait.
• Effect operations use explicit effect declarations plus perform Effect.op(...); reusable unions use effect Name = A | B.
• Error sets are checked contracts: throw expr must match the current ! E1 | E2, calling a throwing function requires compatible caller errors, and ? is propagation sugar.
• Current implementation primitives are I32/I64/U32/U64/F32/F64/Bool/Str/(). The locked surface also keeps Int/Float as I64/F64 aliases; implementation catch-up is tracked separately.
• The live structured-concurrency surface includes parallel_scope { ... }, spawn { ... }, postfix task.await, Channel.new[...], and select { ... timeout(...) => ... }.

Quick Start

cargo build                                      # build the compiler
cargo run --bin spore -- new hello-app          # create a new application project
cd hello-app && ../target/debug/spore run src/main.sp  # run the application from this checkout
cargo test --all                                 # run all compiler tests

For single-file exploration:

cargo run --bin spore -- run examples/demo.sp   # run standalone file (no Platform)
cargo run --bin spore -- check examples/demo.sp # type-check standalone file
cargo run --bin spore -- test examples/demo.sp  # validate spec examples in file

If spore is installed on your PATH, you can replace the explicit Cargo or target/debug/spore invocations above with bare spore ....

Examples

Hello World (Application Project)

The canonical way to write Spore programs is as a project with a Platform contract:

spore new hello-app

This generates src/main.sp with a Platform-aware entry point:

import basic_cli.stdout

fn main() -> () uses [Console] {
    println("Hello from hello-app!")
    return
}

Applications declare fn main() -> () and require effects that are handled by the Platform. The basic-cli Platform handles effect operations like Console for terminal IO.

Standalone File Mode

For quick experiments, you can run single .sp files without a project:

fn demo() -> I32 {
    let x = 42;
    x * 2
}

fn main() -> I32 {
    demo()
}

Standalone mode does not participate in a package-backed Platform contract and does not have access to platform builtins such as println. Console I/O requires a project with an explicit Platform effect boundary (e.g. basic-cli). See examples/demo.sp for a standalone example file.

Structs and Pattern Matching

struct Point { x: I32, y: I32 }

type Shape {
    Circle(I32),
    Rect(I32, I32),
}

fn area(s: Shape) -> I32 {
    match s {
        Circle(r) => r * r * 3,
        Rect(w, h) => w * h,
    }
}

Lambdas, Pipes, and Higher-Order Functions

fn apply(f: (I32) -> I32, x: I32) -> I32 { f(x) }

fn compute() -> I32 {
    let double = |x: I32| x * 2;
    apply(double, 21)
}

Required Effects, Costs, and Error Sets

These annotations are part of the function signature — the compiler verifies required effects, cost budgets, checked error contracts, and explicit effect surfaces at call boundaries. throw expr must be covered by the current function's ! E1 | E2, calling a throwing function requires a compatible caller signature, and ? is sugar for that propagation rule.

The parser accepts where, uses, cost, and spec clauses in any order. Documentation examples use the canonical order: where, uses, cost, spec, and stable where syntax is a single comma-separated clause such as where T: Trait, U: Trait. Active cost syntax is the fixed-order vector cost [compute, alloc, io, parallel]; each slot currently uses the minimal subset only: integer constants, parameter variables, or linear O(n) terms. Old scalar cost <= expr, log/max/min, and richer algebraic terms are deferred.

effect NetConnect {
    fn fetch(url: Str) -> Str ! NetError | Timeout
}

fn fetch(url: Str) -> Str ! NetError | Timeout
    uses [NetConnect]
    cost [1, 0, 1, 0]
{
    perform NetConnect.fetch(url)
}

Parallel Fetch

fn fetch_all(urls: List[Str], n: I32) -> List[Str] ! NetError | Timeout
    uses [NetConnect, Spawn]
    cost [O(n), O(n), n, n]
{
    parallel_scope {
        urls |> map(|url| spawn { fetch(url) })
             |> map(|task| task.await?)
    }
}

This is part of the live structured-concurrency surface: the parser, typechecker, and interpreter all cover the current parallel_scope / spawn / await / select subset. Until richer cost-slot terms land, examples use explicit parameters such as n instead of projections like urls.len. The same active-docs target also uses Channel.new[...] and select { msg from rx => ..., timeout(5.seconds) => ... }.

Traits and Implementations

trait Display[T] {
    fn show(self: T) -> Str
}

impl Display for Point {
    fn show(self: Point) -> Str { "point" }
}

Architecture

sporec (stateless compiler CLI / product)
└── sporec-driver    Host-side compiler driver crate
    ├── sporec-parser     Source text -> AST
    ├── sporec-typeck     Type checking, effect & cost analysis
    │   ├── hir          HIR with pipe desugaring
    │   ├── effect sets  Effect-set algebra (∪/∩/hierarchy)
    │   ├── cost         4D cost vectors + cost checker
    │   ├── hole         Hole dependency graph + topological ordering
    │   ├── sig_hash     BLAKE3 256-bit signature hashing
    │   ├── incremental  Incremental compilation DB
    │   ├── module       Module registry + import resolution
    │   ├── concurrency  Structured concurrency analysis
    │   └── platform     Platform system (cli/web/embedded)
    └── sporec-codegen   Tree-walk interpreter (PoC) / Cranelift (planned)

spore (stateful codebase manager — handles IO / project workflow)
├── File watching, incremental compilation
├── Package management (content-addressed)
├── Platform management
└── LSP server (spore-lsp)

Project Status

Compiler infrastructure implemented. Parser is feature-complete for the syntax spec. Type checker covers unification, pattern exhaustiveness, trait conformance, error set checking, cost analysis, and the current structured-concurrency subset. Interpreter is a PoC tree-walking evaluator with enum constructors, 30+ builtin functions (list/string/math/IO), method-style dispatch, try-operator support, and the current structured-concurrency runtime.

See docs/DESIGN.md for the canonical in-repo design document. Topic-level normative proposals live in the sibling spore-evolution repo under seps/.

Packaging

The spore CLI is packaged from crates/spore via maturin so it can be built and published as a PyPI binary package.

just package-cli        # build a wheel into dist/
just package-cli-sdist  # build a source distribution into dist/

Development

Local hooks

just pre-commit-install  # install pre-commit + commit-msg hooks via prek
just pre-commit          # run the configured hooks on all files

In this repository, the local Spore hooks intentionally focus on the canonical example surface under examples/. The reusable published hooks below are for arbitrary .sp files in downstream repos.

Reusable hooks

With the root pyproject.toml in place, the repository can also expose reusable pre-commit hooks for .sp files:

repos:
  - repo: https://github.com/spore-lang/spore
    rev: <tag-or-sha>
    hooks:
      - id: spore-format
      - id: spore-check

Until a dedicated thin mirror repo exists, installing these hooks from the source repo still builds Spore from source, so consumers need a working Rust toolchain.

Documentation

Canonical design docs

Document	Description
docs/DESIGN.md	Primary in-repo design document, syntax authority, and durable design summary
docs/specs/README.md	Redirect for the retired per-topic spec drafts
docs/research/README.md	Redirect for the retired research drafts

SEP mapping

Detailed topic proposals now live in spore-evolution/seps/:

• SEP-0001-core-syntax.md
• SEP-0002-type-system.md
• SEP-0003-effect-system.md
• SEP-0004-cost-analysis.md
• SEP-0005-hole-system.md
• SEP-0006-compiler-architecture.md
• SEP-0007-concurrency-model.md
• SEP-0008-module-package-system.md
• SEP-0009-standard-library.md

License

MIT OR Apache-2.0