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roblox-luau-core

roblox-luau-core

github.com/tabooharmonyDevelopment1382.0k installsUpdated 2w ago
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About roblox-luau-core

A language reference skill for Luau semantics and common translation pitfalls from JavaScript and Python. It is intended for developers writing or reviewing Luau, with concise rules and examples covering runtime behavior and syntax.

Key features

  1. 01Truthiness and equality rules
  2. 02Tables and iteration behavior
  3. 03Luau syntax and string patterns
  4. 04Binary data and encoding guidance
  5. 05JavaScript and Python translation traps

Use cases

  1. 01Checking Luau language behavior
  2. 02Translating JavaScript code to Luau
  3. 03Reviewing code for cross-language assumptions

Install

Copy the command and run it in a terminal.

$npx skills add https://github.com/tabooharmony/roblox-brain --skill roblox-luau-core

After installing, type/roblox-luau-corein Claude Code to confirm it loaded.

Bundled filesreferences/full.md

Details

From the project README

Luau Core Language

When to Load

Load for Luau semantics and JS/Python translation. Types: roblox-luau-types; lifecycle: roblox-luau-patterns; engine APIs: domain skills.

Quick Reference

  • Only false and nil are falsy. 0, "", and {} are truthy.
  • Equality does not coerce types. 0 == "0" is false. Inequality is ~=.
  • Array conventions are 1-based. #array is meaningful only for a sequence without nil gaps.
  • Assigning nil removes a table key; assigning a table copies the reference; table.clone is shallow.
  • Dictionary iteration order is unspecified. Do not make behavior depend on it.
  • Dynamic keys require brackets: record[field]. Dot syntax uses a literal identifier.
  • Missing arguments become nil; extra results and arguments can be discarded.
  • Prefer an if expression over condition and a or b when a may be falsy.
  • Locals start at their declaration; repeat locals reach until. Forward-declare mutual recursion.
  • Luau string patterns are not regular expressions. Their syntax and capabilities differ.
  • Backtick interpolation and .. are valid. Join many fragments once in hot loops.
  • NaN does not equal itself and defeats </>; test with x ~= x.
  • Binary data uses the buffer library: fixed size, 0-based offsets, explicit-width reads/writes. Avoid buffer.readinteger/writeinteger (stubs, not released runtime).
  • For Base64, hashing, or compression use EncodingService (buffers, not strings; JSON via HttpService). Details: see full reference.
local label = if enabled then "On" else "Off"
local message = `{name}: {score}`

local byId: {[number]: string} = {}
byId[userId] = name

for index, value in values do
    print(index, value)
end
Translation traps
  • JavaScript ===, !==, null, optional chaining, spread, arrow functions, and array methods are not Luau syntax.
  • Python None, zero-based list assumptions, list comprehensions, exceptions, and implicit tuple behavior do not translate directly.
  • x or fallback tests truthiness, not only absence. It replaces a valid false value.
  • typeof(value) recognizes Roblox datatypes; type(value) reports the underlying Luau type category.
Review

Valid Luau, no nil gaps, no assumed dictionary order, no accidental aliases, no cross-language syntax, no fallbacks hiding false or nil.

Detailed language traps and translation examples: references/full.md

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