flow like the river

BACK_BACK/node_modules/graphql/jsutils/naturalCompare.js.flow

@@ -0,0 +1,59 @@
+// @flow strict
+/**
+ * Returns a number indicating whether a reference string comes before, or after,
+ * or is the same as the given string in natural sort order.
+ *
+ * See: https://en.wikipedia.org/wiki/Natural_sort_order
+ *
+ */
+export default function naturalCompare(aStr: string, bStr: string): number {
+  let aIdx = 0;
+  let bIdx = 0;
+
+  while (aIdx < aStr.length && bIdx < bStr.length) {
+    let aChar = aStr.charCodeAt(aIdx);
+    let bChar = bStr.charCodeAt(bIdx);
+
+    if (isDigit(aChar) && isDigit(bChar)) {
+      let aNum = 0;
+      do {
+        ++aIdx;
+        aNum = aNum * 10 + aChar - DIGIT_0;
+        aChar = aStr.charCodeAt(aIdx);
+      } while (isDigit(aChar) && aNum > 0);
+
+      let bNum = 0;
+      do {
+        ++bIdx;
+        bNum = bNum * 10 + bChar - DIGIT_0;
+        bChar = bStr.charCodeAt(bIdx);
+      } while (isDigit(bChar) && bNum > 0);
+
+      if (aNum < bNum) {
+        return -1;
+      }
+
+      if (aNum > bNum) {
+        return 1;
+      }
+    } else {
+      if (aChar < bChar) {
+        return -1;
+      }
+      if (aChar > bChar) {
+        return 1;
+      }
+      ++aIdx;
+      ++bIdx;
+    }
+  }
+
+  return aStr.length - bStr.length;
+}
+
+const DIGIT_0 = 48;
+const DIGIT_9 = 57;
+
+function isDigit(code: number): boolean {
+  return !isNaN(code) && DIGIT_0 <= code && code <= DIGIT_9;
+}