isFirstSelectionInGroup

function LSM.isFirstSelectionInGroup<T>(lsm: LSM<T>, selectable: T): boolean;

Returns true if the item is the first selection in any contiguous group.

Groups are determined by position in the selectables array, not selection order.

Example

import { LSM } from "@monstermann/lsm";

let lsm = LSM.create(["a", "b", "c", "d", "e"]);
lsm = LSM.goTo(lsm, "b");
lsm = LSM.selectNext(lsm);
lsm = LSM.select(lsm, "e");

// Groups: [["b", "c"], ["e"]]

LSM.isFirstSelectionInGroup(lsm, "b"); // true
LSM.isFirstSelectionInGroup(lsm, "c"); // false
LSM.isFirstSelectionInGroup(lsm, "e"); // true