pc2 / pc2/sus-compiler

Use `_` both as 'don't care' value, as well as unused result placeholder

Open
#189 0 comments 0 reactions 0 assignees View on GitHub

Nobody has claimed this yet.

enhancement Language Design
Dominant language
Rust
Stars
126
Forks
6
PR merge metrics
No merged PRs in 30d

Description

_ shouldn't be declared, rather, it's a keyword available everywhere.

So you could write:

int x, _ = divmod(20, 7)
bool wr_to
when do_write {
  wr_to = false
} else {
  wr_to = _
}

Contributor guide

Open the contributing guide

First steps

  1. Read the whole issue, then the project's contributing guide.
  2. Comment on the issue to say you are picking it up — it saves two people doing the same work.
  3. Fork the repository and make your change on a branch.
  4. Open a pull request that references the issue number.

Research direction

The issue names no files, tests, or entry points. First locate where _ is parsed and validated, then trace the existing handling of don't-care values and unused results; done means both uses in the examples are accepted without requiring a declaration, with tests covering the behavior.

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
Quiet
Clarity
Mostly clear
Newbie friendliness
35/100

Get new issues in your inbox

A short digest of beginner-friendly GitHub issues.