Lazy Sequences

Lazy sequences are a programming concept where elements of a sequence are computed on-demand rather than all at once, enabling efficient handling of potentially infinite or large data sets. This approach defers computation until the value is actually needed, which can save memory and improve performance by avoiding unnecessary calculations. It is commonly implemented in functional programming languages and libraries through constructs like generators, streams, or iterators.

Also known as: Lazy evaluation sequences, Lazy lists, Streams, Generators, Iterators

Why learn Lazy Sequences?

Developers should learn lazy sequences when working with large data streams, infinite sequences, or performance-critical applications where memory efficiency is key, such as in data processing pipelines or real-time analytics. They are particularly useful in functional programming to enable composable operations without intermediate storage, and in scenarios like reading files line-by-line or generating sequences on-the-fly in game development or simulations.

Learning Resources

• docs: MDN Web Docs: Iterators and Generators
• docs: Clojure Docs: Lazy Sequences
• tutorial: Python Generators Tutorial
• docs: Functional Programming in Scala: Lazy Evaluation
• video: YouTube: Lazy Evaluation Explained