The meaning of the word “reify” in programming

I don’t recall hearing of the words “reify” or “reification” in my OOP years, but that may be because I studied aerospace engineering in college, not computer science. Since learning functional programming (FP) I often see those words, so I thought I’d try to understand their meaning.


I ran into the word “reify” when I saw code like this:

trait Foo {

object Foo extends Foo

I’d see that code and eventually saw that someone described that last line as a “reification” process.

What “reify” means

The short answer is that the main definition of reify seems to be:

“Taking an abstract concept and making it concrete.”

For the longer answer, I found the following definitions and examples of reification.

I’m surprised when functional programmers say bad things about Scala

I’m surprised when many functional programmers feel the need to say something bad about Scala. As a community, that makes them seem like a bunch of people who aren’t very nice. There are things I don’t like about Haskell, F#, Lisp, Scala, Kotlin, Go, Perl, PHP, Python, C, C++, etc., but I don’t feel the need to take pot shots at any languages or individuals.

Why Haskell has monads

“If it wasn’t for the problem of how to sequence input-output actions correctly, monads probably wouldn’t have appeared in Haskell. But once it was appreciated what they could do, all kinds of other uses quickly followed.”

~ Thinking Functionally with Haskell, Richard Bird

An initial review of Functional and Reactive Domain Modeling

I’m not yet sure if I like the book Functional and Reactive Domain Modeling, but one thing is for sure: I couldn’t begin to understand it if I didn’t first do the research to write Learning Functional Programming in Scala. The author immediately jumps into monads as if they are commonly understood, and also designs his functions as “modules” in a very Haskell-ish way. I’m not saying the book is bad, just that it has a high barrier to entry.

Notes from “Thinking Functionally with Haskell”

I’m always curious about how people think, and these days I’m most interested in how functional programmers think about programming problems. Along those lines I found a good blog post (tutorial) titled, “Thinking Functionally with Haskell”, and these are my notes from that post: