Lesson 22. Interacting with the command line and lazy I/O

After reading lesson 22, you’ll be able to

  • Access command-line arguments
  • Use the traditional approach to interacting through I/O
  • Write I/O code using lazy evaluation to make I/O easier

Often when people first learn about I/O and Haskell, they assume that I/O is somewhat of a challenge for Haskell because Haskell is all about pure programs and I/O is anything but pure. But there’s another way to view I/O that makes it uniquely suited to Haskell, and somewhat clunky in other programming languages. Often when working with I/O in any language, we talk about I/O streams, but what is a stream? One good way to understand I/O streams is as a lazily evaluated list of characters. STDIN streams ...

Get Get Programming with Haskell now with the O’Reilly learning platform.

O’Reilly members experience books, live events, courses curated by job role, and more from O’Reilly and nearly 200 top publishers.