Tail call signature equality check only really needs to be subtyping
Nobody has claimed this yet.
- Dominant language
- Rust
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- 119k
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Description
We have a check for become f() tail calls which enforces that the callee's signature is compatible with the caller's signature.
Right now that compatibility check enforces equality of arguments, but I think it only should require a subtyping relationship between arguments.
I'm just opening this issue to track this so we don't forget that we should relax this and also reason about why it's sound.
Contributor guide
First steps
- Read the whole issue, then the project's contributing guide.
- Comment on the issue to say you are picking it up — it saves two people doing the same work.
- Fork the repository and make your change on a branch.
- Open a pull request that references the issue number.
Research direction
Start by locating the compiler check for become f() tail calls and reading how it compares the callee and caller signatures. The work is done when argument compatibility uses a subtyping relationship rather than equality and the soundness of that relaxation has been reasoned about.
Written by the indexing model from the issue text.
Assessment
- Tech stack
- rust
- Domain
- compilers
- Issue type
- Feature
- Difficulty
- 5/5
- Estimated time
- Over a week
- Activity status
- Stale
- Clarity
- Needs clarification
- Newbie friendliness
- 25/100