Great book! It was the textbook for my class on programming language theory in grad school. I had heard so much about the lambda calculus, but I could never und

Great book! It was the textbook for my class on programming language theory in grad school. I had heard so much about the lambda calculus, but I could never understand it from Wikipedia alone. The book did a great job of introducing how things work in lambda calculus and motivating the desire for typed lambda calculus. You implement various common programming language abstractions in pure simply typed lambda calculus, and then replace those patterns with new syntax. Then you start to see a familiar looking programming language take shape. This was good background for me to have to be able to understand the development of evolving programming languages built on academic formalism, like Scala.