seed Overview

seed is a statically typed, imperative, expression-oriented systems language. It targets straightforward Python-like readability where possible while retaining C/Rust-class control over layout, execution, linkage, and low-level hardware access.

The language has no GC, lifetime syntax, exception unwinding, hidden async runtime, or mandatory libc. Costs such as allocation, deep clone, reference- count retain, blocking, syscalls, and dynamic loading are explicit.

Current identity

• language name: seed
• source extension: .sd
• source encoding: UTF-8
• text: owned string and borrowed str, both valid UTF-8
• identifiers: ASCII; value names use lower snake case, nominal types and variants use UpperCamelCase
• constants: ASCII upper snake case
• compiler: operational clean LLVM compiler under compiler/llvm

Core model

• copy scalars;
• move owned resources;
• borrow read-only views allocation-free;
• clone explicitly;
• clean live managed values exactly once on structured exits;
• use linear t for exactly-once obligations;
• use unsafe only around audited raw operations;
• use ADTs, result/option, exhaustive match, and ? for recoverable flow;
• use structured spawn and ordinary task/channel libraries instead of async/await.

Small core and ecosystem

Files, networking, processes, serialization, formatting, collections, and synchronization live in separately compiled libraries. Hosted libraries are shared dynamically by default; static linkage is explicit. Freestanding, kernel, driver, and boot programs use the same language under restricted runtime profiles.

Current limits

The clean compiler implements phase-1 and phase-2 f-strings for text, bool, integers, IEEE-754 floats, format specifiers, and static display/debug traits. It does not implement legacy type-based ADTs, lower snake case nominal names, ret, elif, # comments, built-in chan<t>/send/recv, detached spawn, macros, or a language-level handle returned directly by spawn. The task library provides typed structured results. Reproducible packages, LSP, doc/lint, and exact incremental artifacts are implemented by Gate 15 tooling.

Gate 14 portability is closed for its recorded rows: Windows x86-64 passes under required Wine, and macOS x86-64 closed by required native Intel execution. The canonical matrix is compiler/llvm/tests/GATE14_TARGET_MATRIX.tsv, whose macOS arm64 row remains cross-link-only; that baseline states it must not be presented as executed until a trusted arm64 runner passes the suite. Object support is not the same as executable hosted support.

Start here

• Current Status
• Language Reference
• Ownership
• Core Built-ins
• System Primitives