collections

Higher-level data structures: Counter, Stack, PriorityQueue, Deque, Set, and OrderedMap.

Import

import collections

Types

collections.Counter(arr: [any]) -> map

Returns a map of element counts from the array.

collections.Stack() -> Stack

Creates a LIFO stack. Methods: push(v), pop(), peek(), is_empty(), len().

collections.PriorityQueue() -> PriorityQueue

Min-heap priority queue. Elements with lower priority values are dequeued first.

collections.Deque() -> Deque

Double-ended queue supporting efficient push/pop from both ends.

collections.Set(arr?: [any]) -> Set

Set of unique elements. Pass an array to initialize. Supports add, remove, has, len.

collections.OrderedMap() -> OrderedMap

Map that preserves insertion order. Useful when iteration order matters.

Examples

import collections

-- Counter
let c = collections.Counter(["a", "b", "a", "c", "a"])
println(c["a"])   -- 3
println(c["b"])   -- 1

-- Stack
let s = collections.Stack()
s.push(10)
s.push(20)
println(s.peek())  -- 20
println(s.pop())   -- 20
println(s.len())   -- 1

-- Set
let uniq = collections.Set([1, 2, 3, 2, 1])
println(uniq.len())  -- 3
println(uniq.has(2)) -- true