Cortically Magnified

I wrote this post primarily from the perspective of a beginner guitarist trying to solve a practical problem, but the way I approached it naturally landed on functional programming and literate programming. So, you might want to stay around even if you are not interested in playing the guitar. This post is mostly about my experience of learning a very interesting music markup language LilyPond, which has a symbiotic relationship with the GNU Guile Scheme.

Did you know that in some programming languages, you can give a function a piece of advice? The basic idea is this: if you are using an application or a library written by somebody else, what can you do if you need to modify the behavior of a particular function? You could modify its source code, if your version improves it for everybody. However, if you only want to customize it for your personal needs, a more lightweight solution might be desirable.

In this post, I’ll summarize what I’ve learned from an attempt to gain a deeper understanding of two important concepts in programming: Python’s generators and Scheme’s continuation. The aim is not to teach Python or Scheme programming. Rather, what I want to do is to demonstrate that generators are special cases of a much more powerful construct - continuations. Continuations allow programmers to invent new control structures, and it is the foundation upon which iterators, generators, coroutines, and many other useful constructs can be built.

Program like writers do Programming is traditionally seen as an exercise that translates human thoughts into a format that computers can understand. As a result, the ideas behind the program can become obscured and fragmented in the source code. This is why reading code requires so much mental effort. For me, reading code often feels like solving a puzzle, or reading modernist/postmodernist novels where events are narrated out of sequence. The concept of literate programming was introduced by Donald Knuth in the 80’s to address this issue.