Work-in-progress programming language.

Heavily inspired by other languages in the same category: Lua, Python, and JavaScript.

Working in this repository only requires a recent version of the Rust compiler and Cargo.

Run tests:

cargo test

Update snapshot tests (requires cargo-insta):

cargo review

New tests can be created by adding a .hi file to tests/inputs.

Files in tests/inputs are passed through the tokenize and parse stages.

They may begin with a comment (##) to filter the stages it will be tested against:

• tokenize for src/token.rs
• parse for src/parser.rs

This can also be used to completely disable test files. Adding an empty comment to the top of the file will cause it to not be tested against any stage.

Multiple different stages may be combined, e.g. tokenize,parse will run only through those two stages, but not through the bytecode emit.

Files in tests/inputs/codegen are passed through codegen. These tests always fail if they fail to parse. The resulting bytecode is disassembled for the snapshot.

Files in tests/inputs/run are passed through the runtime, end-to-end.

Try to keep tests minimal and to the point as much as possible. Separate tests should be written for each stage where the behavior may have changed. If a change in codegen may result in different runtime behavior, it should have both a codegen test and a run test.

The implementation heavily relies on code generated from custom DSLs:

• AST is generated from nodes.ast, using astgen
• Instruction set is generated from opcodes.s, using asmgen

Both code generators have a runtime.rs file, which is the place for any helpers and types used by the generated code. It is concatenated together with the generated code to produce the final result.

After changing anything, run

cargo codegen

To re-generate code.

Licensed under either of

• Apache License, Version 2.0 (LICENSE-APACHE or http://www.apache.org/licenses/LICENSE-2.0)
• MIT license (LICENSE-MIT or http://opensource.org/licenses/MIT)

at your option.

Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.