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Lesson 33. Capstone: SQL-like queries in Haskell

This capstone covers

• Using the Monad type class to create SQL-like queries on lists
• Generalizing functions written for one Monad (for example, List) to many
• Organizing functions with types

In the preceding lesson, you saw how List as a Monad can also be understood as a list comprehension, which is used heavily in Python. In this capstone, you’re going to take your use of lists and monads one step further to create a SQL-like interface to lists (and other monads). SQL is used as the primary means to query relational databases. It has a clean syntax for representing the relationships between data. For example, if you had data about teachers teaching classes, you could query the teachers teaching ...