Standard Lua Libraries

The following Lua 5.4 standard libraries are available:

Library	Description
base	Core functions (print, type, pairs, ipairs, tonumber, tostring, etc.)
table	Table manipulation (table.insert, table.remove, table.sort, etc.)
string	String manipulation (string.sub, string.format, string.match, etc.)
math	Math functions (math.sin, math.random, math.floor, etc.)
coroutine	Coroutines (coroutine.create, resume, yield, wrap, …)
utf8	UTF-8 helpers (utf8.char, utf8.codes, utf8.len, …)

Not available (for sandboxing): io, os, package, debug. The base functions dofile and loadfile are removed. load accepts text chunks only (bytecode is rejected), as do app main.lua files and sys.loadlib.

Numbers

PicoDeck Lua uses 32-bit integers and single-precision floats (LUA_32BITS):

• Integers wrap at ±2^31 (0xDEADBEEF is negative; %x still prints the 32-bit pattern). sys.getTimeMs() goes negative after ~24.8 days of uptime (differences still wrap correctly).
• Floats have ~7 significant digits; integers are exact only up to 2^24; 1e39 == math.huge. JSON numbers above 2^24 lose precision the same way.
• Float formatting (tostring, .., string.format, JSON, REPL) is the same on the device and the simulator and matches glibc: tostring(51.0) is "51.0", NaN prints nan. Subnormals (< 1.2e-38) print 0.0 on the device.
• Arguments that are quantities (coordinates, sizes, durations, volumes, rates, frame indices) round to nearest, so 199.99998 counts as 200. NaN, inf and values beyond ±2^24 are argument errors. Volumes, colour components, effect factors and brightness clamp to their range. Handles, enum values, colours, masks, byte counts and ports must be exact integers.

Limits

• LUAI_MAXSTACK = 1000 slots (a frame costs 10-13 slots: recursion tops out around 80-100 Lua levels).
• LUAI_MAXCCALLS = 60: Lua→C→Lua nesting (e.g. string.gsub callbacks calling gsub) stops at ~58 levels with a catchable "C stack overflow".
• The Lua VM runs on its own 64 KB stack in PSRAM.