Effective Haskell

Creating a Pager

A pager is a program that lets a user display text from a file one page at a time. The term “pager” isn’t used very frequently these days, but if you’ve ever used common command-line programs like less or man you’ve used a pager.

A pager is a great example of a small utility that will let you apply all of the different concepts that you’ve been learning about to build a single complete application that does something recognizable while still being small enough to start and finish as you work through this chapter.

Fundamentally, our pager needs to let us do three things:

1. Output the contents of an ASCII or UTF8 encoded text file to the screen
2. Scroll the output backwards and forwards one page at a time
3. Display some metadata, like ...