v1.0 with SW PWA enabled

frontend/node_modules/d3-array/src/quickselect.js

@@ -0,0 +1,53 @@
+import {ascendingDefined, compareDefined} from "./sort.js";
+
+// Based on https://github.com/mourner/quickselect
+// ISC license, Copyright 2018 Vladimir Agafonkin.
+export default function quickselect(array, k, left = 0, right = Infinity, compare) {
+  k = Math.floor(k);
+  left = Math.floor(Math.max(0, left));
+  right = Math.floor(Math.min(array.length - 1, right));
+
+  if (!(left <= k && k <= right)) return array;
+
+  compare = compare === undefined ? ascendingDefined : compareDefined(compare);
+
+  while (right > left) {
+    if (right - left > 600) {
+      const n = right - left + 1;
+      const m = k - left + 1;
+      const z = Math.log(n);
+      const s = 0.5 * Math.exp(2 * z / 3);
+      const sd = 0.5 * Math.sqrt(z * s * (n - s) / n) * (m - n / 2 < 0 ? -1 : 1);
+      const newLeft = Math.max(left, Math.floor(k - m * s / n + sd));
+      const newRight = Math.min(right, Math.floor(k + (n - m) * s / n + sd));
+      quickselect(array, k, newLeft, newRight, compare);
+    }
+
+    const t = array[k];
+    let i = left;
+    let j = right;
+
+    swap(array, left, k);
+    if (compare(array[right], t) > 0) swap(array, left, right);
+
+    while (i < j) {
+      swap(array, i, j), ++i, --j;
+      while (compare(array[i], t) < 0) ++i;
+      while (compare(array[j], t) > 0) --j;
+    }
+
+    if (compare(array[left], t) === 0) swap(array, left, j);
+    else ++j, swap(array, j, right);
+
+    if (j <= k) left = j + 1;
+    if (k <= j) right = j - 1;
+  }
+
+  return array;
+}
+
+function swap(array, i, j) {
+  const t = array[i];
+  array[i] = array[j];
+  array[j] = t;
+}