add comment to partition helper function

Author: Hweinstock

packages/core/src/shared/utilities/tsUtils.ts

@@ -94,6 +94,12 @@ export function createFactoryFunction<T extends new (...args: any[]) => any>(cto
     return (...args) => new ctor(...args)
 }
 
+/**
+ * Split a list into two sublists based on the result of a predicate.
+ * @param lst list to split
+ * @param pred predicate to apply to each element
+ * @returns two nested lists, where for all items x in the left sublist, pred(x) returns true. The remaining elements are in the right sublist.
+ */
 export function partition<T>(lst: T[], pred: (arg: T) => boolean): [T[], T[]] {
     return lst.reduce(
         ([leftAcc, rightAcc], item) => {