$ show ProvableHQ/leo
This repository is the official compiler and toolchain for the Leo programming language, a statically-typed language for writing private zero-knowledge applications on the Aleo blockchain. The codebase implements a full compilation pipeline from Leo source to Aleo bytecode, including parsing (with a lossless rowan-based parser), type checking, static analysis, multiple optimization passes (constant propagation, loop unrolling, dead code elimination, common subexpression elimination, SSA formation, function inlining, flattening, destructuring, storage lowering, option lowering, peephole optimization), and code generation targeting snarkVM. Beyond the compiler, it provides a complete development environment: a CLI with commands for building, testing, deploying, executing, and querying the Aleo network; a Language Server Protocol (LSP) implementation with diagnostics, goto-definition, references, rename, and semantic tokens; a standalone formatter; a package manager supporting local, git, network, and workspace dependencies with lock files; and an ABI generation and compatibility checker. The architecture is a multi-crate Rust workspace with clear separation of concerns, extensive test coverage (unit, integration, and expectation-based compiler tests), and CI/CD pipelines. The codebase demonstrates high craftsmanship with reusable patterns such as a generic directed graph with cycle detection, a canonicalization trait for structural equality, an intern-based type system, and a pass-based compiler architecture.
The LLM identified 5 files worth highlighting for reuse:
A generic directed graph implementation (DiGraph) with cycle detection, transitive closure, post-order traversal, and node retention. Uses IndexMap/IndexSet for deterministic ordering. Self-contained and reusable for any graph problem requiring cycle analysis or topological ordering.
The Canonicalize trait and its exhaustive implementations for all AST nodes. It strips positional metadata (Span, NodeID) while preserving identity-bearing payloads, enabling structural equality comparisons. The pattern uses exhaustive destructuring to ensure compile-time errors if new fields are added, making it a robust pattern for scrubbing metadata in any tree structure.
A TypeInterner that assigns stable integer handles to canonical TypeKind variants. Provides intern-based equality and conversion to snarkVM types. Self-contained and reusable for any system requiring interned type representations with structural equality.
A peephole optimization pass for Aleo bytecode that performs identity operation folding, trivial assert elimination, dead register elimination, consecutive cast folding, and register renumbering. It distinguishes pure vs. side-effecting instructions for safe removal. Self-contained and could be reused as a standalone optimizer for Aleo bytecode.
The Lock struct manages dependency lock entries for git dependencies, supporting record, carry-over, and remove-name operations. It handles offline resolution, workspace lock sharing, and path-escape prevention. Self-contained and reusable for any package manager needing a lock file for git dependencies.