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API Reference — PolyNode, ItemHandle, Slot

New to the concepts? See Building Blocks — PolyNode
first.

This page covers the actual Zig types and functions.

const polynode = @import("matryoshka").polynode;

// typical usage:
var slot: polynode.Slot = &event.poly;   // slot holds the node
slot = null;                              // slot is empty

Types

pub const PolyTag = struct { _: u8 = 0 };

pub const PolyNode = struct {
    node: std.DoublyLinkedList.Node,
    tag:  *const anyopaque,
};

pub const ItemHandle = *PolyNode;
pub const Slot = ?ItemHandle;

  • PolyNode is the type every Item embeds. Its tag is a unique address that identifies which type a node lives inside (see Step 2).

  • ItemHandle is a pointer to that embedded field — the only thing Matryoshka moves.

  • Slot is where a handle lives while it is yours.

Next: reset / is_linked.