René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"[RFC] Split oparg type from the opcode enum","articleBody":"## Summary\n\nIntroduce a new `AnyOparg` enum \u0026 make `Instruction` + `PseudoInstruction` enums to not hold the oparg type.\n\n## Detailed Explanation\n\nThe current `Instruction` enum couples the opcode and its oparg type together. In practice, this creates friction and many boilerplate code that can be avoided.\n\n### Suggested API\nNew pure `Opcode` enum that will have only the mapping between the opcode name and it's ID, like this:\n```rust\nenum Opcode {\n   Nop = 0,\n   IsOp = 1,\n   BinaryOp = 2,\n   ...\n}\n```\n\nA new `AnyOparg` enum that will have all oparg types as it's variants:\n```rust\nenum AnyOparg {\n    NameIdx(oparg::NameIdx),\n    IntristicFunction1(oparg::IntristicFunction1),\n    Invert(oparg::Invert),\n    ...\n}\n```\n\nAn `Instruction` struct that is like a typed version of the `CodeUnit` struct:\n```rust\nstruct Instruction {\n  opcode: AnyOpcode,\n  oparg: AnyOparg,\n}\n\nimpl Instruction {\n  pub fn new\u003cT: Into\u003cAnyOpcode\u003e\u003e(opcode: T, oparg: Option\u003ci32\u003e) -\u003e Result\u003cSelf, MarshalError\u003e {\n    let oparg = match opcode.into() {\n      AnyOpcode::Real(Opcode::Nop) =\u003e None,\n      AnyOpcode::Real(Opcode::IsOp) =\u003e Some(oparg::Invert::try_from(oparg.unwrap())?),\n      ...\n    };\n\n    Ok(Self { opcode: opcode.into(), oparg: oparg.map(Into::into) })\n  }\n}\n```\n\n## Drawbacks, Rationale, and Alternatives\n### Drawbacks\n- Will require a serious refactoring to the code\n\n### Rational\n- Reduce boilerplate code (use `num_enum` crate for example).\n- Easier to auto-generate the opcodes (and their IDs) in the future.\n- Simplify `opcode -\u003e oparg` mapping.\n\n## Unresolved Questions\n\nPerformance implifications?\n\nImplementation \u0026 refactoring efforts?\n\n","author":{"url":"https://github.com/ShaharNaveh","@type":"Person","name":"ShaharNaveh"},"datePublished":"2026-01-16T14:03:16.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":1},"url":"https://github.com/6746/RustPython/issues/6746"}