debug.isvalidlevel - Mintlify Starter Kit

Checks whether a number is a valid stack level for the thread that calls it.

debug.isvalidlevel(level: number): boolean

New to stack levels? Learn more here. It tracks debug.getinfo exactly: a level this returns true for is one debug.getinfo can read, and a level it returns false for is one debug.getinfo errors on.

Parameters

Parameter	Type	Description
`level`	`number`	Which stack frame to test.

Returns

boolean - true for a level the calling thread currently has on its stack, false for one it does not.

Aliases

isvalidlevel
validlevel

Example

Measure how deep the current call stack is by counting levels until debug.isvalidlevel runs off the top.

<<<<<<< HEAD
local isvalidlevel = debug.isvalidlevel(8)
=======
-- debug.isvalidlevel(level: number): boolean
>>>>>>> 50e30f53759b0538759af25c9b271514aa2c9290

local function stackDepth()
    local level = 0
    while debug.isvalidlevel(level) do
        level += 1
    end
    return level
end

local function inner()
    print(`inner: {stackDepth()} levels`)
end

print(`top level: {stackDepth()} levels`)
inner()
-- inner() prints the higher number: it runs one call deeper, so
-- isvalidlevel stays true for more levels before it runs off the top

Useful for iterating up the stack without causing stack level out-of-range errors.