vdom‑thunk is a small library that adds a “thunk” primitive to the virtual‑dom ecosystem (virtual‑dom, vtree, virtual‑hyperscript). It lets developers wrap expensive subtree‑rendering functions so they are only recomputed when their input arguments change, improving performance for UI code that uses immutable data structures. The package is aimed at JavaScript developers building fast, diff‑based front‑ends with virtual‑dom libraries.