component_utils

Helpers for Luau-backed components that mirror Rust ECS components. The Luau side declares camelCase keys on a public table; the Rust side expects snake_case. This module centralises the (almost entirely mechanical) name conversion and the projection of a public table down to the reactive subset that the native side actually wants.

Exports

• M.toSnake(key: string, overrides: Overrides?) -> string — convert a camelCase Luau key to its snake_case Rust counterpart. Splits on lower→upper and lower→digit transitions; overrides[key] short-circuits the rules for one-off renames like type → body_type.
• M.projectKeys(public: { [string]: any }, reactive: ReactiveSet, overrides: Overrides?) -> { [string]: any } — build a snake_case-keyed payload by reading every reactive key off public and renaming via toSnake. Keys outside reactive are skipped.

Types:

• Overrides = { [string]: string } — Luau-key → explicit Rust-key map.
• ReactiveSet = { [string]: any } — used as a set; only the keys matter.

Usage

local CU = require("@builtin::modules.component_utils")

CU.toSnake("angularDamping")                 -- "angular_damping"
CU.toSnake("colorR")                          -- "color_r"
CU.toSnake("layerUI")                         -- "layer_ui"
CU.toSnake("is2D")                            -- "is_2d"
CU.toSnake("type", { type = "body_type" })  -- "body_type"

local data = CU.projectKeys(public, REACTIVE, { type = "body_type" })
__native.insert(data)

Notes

• Pure functions; no engine state. Safe to call from any context.
• projectKeys returns a fresh table on every call. Mutate the result freely (e.g. apply per-component value transforms like data.body_type = capitalize(public.type)).
• Consecutive uppercase letters are treated as one word (layerUI → layer_UI → layer_ui, parseURL → parse_URL → parse_url). This matches the Rust snake_case convention for identifier-embedded acronyms.