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Stack

Based on game build 714014 | Last updated: 2026-02-27

Overview​

The Stack component provides a simple, standalone implementation of a Last-In-First-Out (LIFO) stack data structure. It is not an ECS component and is used purely as a utility helper for managing ordered collections of values in Lua code. It is typically instantiated via Stack:Create() and supports basic stack operations: push, pop, size query (getn), linear search (find), and debug listing (list).

This file is located in map/stack.lua, indicating it may be used in world generation or map-related scripts, though its generic nature allows use across any context where ordered value management is needed.

Usage example​

local Stack = require("map/stack")
local s = Stack:Create()

s:push("apple", "banana", "cherry")
print(s:getn()) -- 3

local item1 = s:pop()
print(item1) -- "cherry"

local a, b = s:pop(2)
print(a, b) -- "banana", "apple"

print(s:getn()) -- 0

Dependencies & tags​

Components used: None
Tags: None identified.

Properties​

The returned stack object contains only internal state and no documented public properties beyond its methods. The _et field holds the underlying entry table but is not intended for direct external access.

Main functions​

Stack:Create()​

  • Description: Constructs and returns a new stack table with bound methods.
  • Parameters: None.
  • Returns: A table containing stack operations (push, pop, getn, list, find).
  • Error states: None.

stack:push(...)​

  • Description: Adds one or more values to the top of the stack.
  • Parameters:
    • ... (any, variadic): Values to push onto the stack. nil is ignored.
  • Returns: None.
  • Error states: Passing no arguments or only nil results in no modification.

stack:pop(num)​

  • Description: Removes and returns up to num values from the top of the stack (defaults to 1).
  • Parameters:
    • num (number, optional): Number of values to pop. Must be >= 1. Defaults to 1.
  • Returns: Up to num return values in LIFO order. If fewer values remain than requested, only available values are returned (fewer than num).
  • Error states: If stack is empty, returns no values (not even nil).

stack:getn()​

  • Description: Returns the current number of elements in the stack.
  • Parameters: None.
  • Returns: number — the count of stack elements.
  • Error states: None.

stack:list()​

  • Description: Prints stack contents to console for debugging, showing index and value for each entry.
  • Parameters: None.
  • Returns: None.
  • Error states: None.

stack:find(value)​

  • Description: Checks if value exists anywhere in the stack using shallow equality (==).
  • Parameters:
    • value (any): Value to search for.
  • Returns: true if found, false otherwise.
  • Error states: None.

Events & listeners​

This file does not use or emit events.