Interleaving sequence values is useful when you're looking for a value in more than one sequence. This makes it easy to look in every collection without having to search one collection entirely before moving on to the next one:
const myList1 = List.of(1, 2, 3);const myList2 = List.of(4, 5, 6);const myList3 = List.of(7, 8, 9);console.log('found', myList1 .toSeq() .interleave(myList2, myList3) .find((v) => { console.log('checking', v); return v === 7; })); // -> checking 1 // -> checking 4 // -> checking 7 // -> found 7
As the logging shows, you only have to check the values 1 and 4 before finding the value you're looking for. Because you have interleaved the lists using interleave(), you avoid having to check 2
