Mastering Immutable.js

Removing excess iterations

When you're working with large collections, iterating over them can be expensive, especially when there are several of them to iterate over. Sometimes this can't be avoided. For example, a value in one list might depend on a value in a few other lists in the same index. Rather than structure your code so that it requires several iterations, the zip() method can remove these excess iterations.

Instead of having multiple mappers or iteratee functions, you can tell the collection that several other collections are required as arguments passed to a single iteratee. This means that you have to be aware of the order in which lists are zipped.