Roc Zulip Daily Summary — 2026-03-02

  • Realm: https://roc.zulipchat.com
  • Window: 2026-03-02 12:00 AM to 2026-03-03 12:00 AM (America/Los_Angeles)
  • Messages: 14
  • LLM: vertex_open_model model=zai-org/glm-5-maas topics=5 ok=5/5

Top threads

math functions in new compiler

Summary

Guillaume Sarisson asked how to use math functions in the new compiler and whether the Num module still exists. Luke Boswell explained that the module is gone, directed them to the Builtin.roc file, and provided examples of the current syntax for arithmetic operations.

Key points

  • The Num module no longer exists in the new compiler.
  • Built-in functions are now defined in src/build/roc/Builtin.roc.
  • Math operations can be performed using type-specific functions (e.g., U16.plus, U32.div_by) or standard infix operators.
  • The syntax supports a “follower” style where the first argument precedes the function call (e.g., 12.U64.plus(12)).

Open questions

  • None.

Action items

Key links

List concatMany and insert

Summary

Anton grants permission to add List.join and List.insert to the Builtin.roc file, noting that a Roc implementation is acceptable for now with the possibility of a low-level optimization later.

Key points

  • List.join and List.insert may be added to Builtin.roc.
  • It is acceptable to implement List.join in Roc, even if a low-level version might be added later.
  • LLVM optimization may make the underlying implementation details (like tree-based arrays) irrelevant for release builds, though it could still matter for dev backends.

Open questions

  • None.

Action items

Key links

Reassign or redeclare a constant?

Summary

Hubert Małkowski inquired about the rationale for avoiding variable shadowing in Roc, and Anton explained that the restriction is intended to prevent bugs and confusion while simplifying the language.

Key points

  • A user asked why Roc avoids shadowing.
  • The reasons given were to avoid bugs, prevent confusion, and simplify the language design.

Open questions

  • None.

Action items

Datastar

Summary

Richard Feldman shared a video interview about Datastar, describing it as a project that aligns with the htmx philosophy but prioritizes performance-obsessed implementation.

Key points

  • Datastar is described as having an “htmx philosophy” while being “performance-obsessed” in its implementation.
  • The project boasts a small footprint of 10kb total and requires no npm.
  • Feldman expressed strong enthusiasm for the interview and the project’s pitch.

Open questions

  • None.

Action items

Key links

Value showing up as opaque type

Summary

Anton reports encountering a “panic: reached unreachable code” error and has created issue #9229 to track it.

Key points

  • The error message observed was “panic: reached unreachable code”.
  • A specific issue, #9229, was created to document the problem.

Open questions

  • None.

Action items