Written by Pete Corey on Jul 11, 2016.

I’ve always been interested in Donald Knuth’s idea of “literate programming”. Presenting a complete program as a story or narrative is a very powerful framework for expressing complex ideas.

While literate programming is interesting, it’s also uncommon. The practice of literary programming seems to be at odds with how most of us develop software.

Thankfully, with a small shift in perspective we may be able to employ all of the benefits of writing literary software, while leveraging the tools we use on a daily basis.

The Problem With Literate Programming

Literate programming doesn’t come without its share of problems. In a recent article, John Cook does a fantastic job of outlining some of the drawbacks of this style of programming, and how they’ve hindered its wider adoption. Additionally, commenter Peter Norvig gives a compelling argument against literate programming in the comments:

I think the problem with Literate Programming is that assumes there is a single best order of presentation of the explanation. I agree that the order imposed by the compiler is not always best, but different readers have different purposes. You don’t read documentation like a novel, cover to cover. You read the parts that you need for the task(s) you want to do now.

A developer’s experiences, preferences, and goals will lead them to approach the same codebase in very different ways. A new developer looking to take ownership over an existing codebase may be looking for a much more holistic view of the software than a developer looking to fix a single bug.

Choose Your Own Adventure

But what if we had all of the benefits of a literate program without the strict presentation order? What if we could dive into any piece of the code that interests us and read only the sections of documentation that relate to that code?

What would be ideal is a tool to help construct such paths for each reader, just-in-time; not a tool that makes the author choose a single path for all readers.

Peter’s idea of a “reading path” that can be constructed on the fly strikes a chord with me and resembles an experiment I’ve been working on lately.

In an attempt to better document, improve, and share my programming workflow, I’ve been setting aside time for documented, deliberate practice.

During these practice sessions, I write short programs while following what I consider to be “best practices”. I’m very deliberate during these sessions and document the thought process and impetus behind every change with highly detailed, “literate” commit messages.

The goal of this process is to turn the project’s revision history into an artifact, a set of literate commits, that represent my thoughts as I go through the steps of writing professional-level software.

Benefits of Literate Commits

In the short amount of time I’ve been doing them, these practices sessions have been enlightening. Intentional observation of my process has already led to many personal insights.

Slowing down and ensuring that each and every commit serves a singular purpose and adds to the narrative history of the project has done wonders to reduce thrash and the introduction of “stupid mistakes”.

The knowledge that the project’s revision history will be on display, rather than buried in the annals of git log is a powerful motivating factor for doings things right the first time.

The goal is that this repeated act of “doing things right the first time” will eventually turn into habit.

Learning From History

The portion of Peter’s comment that stands out is his desire for a choose-your-own-adventure-style tool for bringing yourself up to speed with a given piece of code.

Imagine finding a section of code that you don’t understand within a project. git blame can already be used to find the most recent commits against that section, but those commits are most likely unhelpful out of context.

Instead imagine that those commit messages were highly detailed, through explanations of why that code was changed and what the original developer hoped to accomplish with their change.

Now go further back. Review all of the related commits that led up to the current state of this particular piece of code.

Read in chronological order, these commits should paint a clear picture of how and why this particular code came into existence and how it has changed over the course of its life.

Those who do not read history are doomed to repeat it.

This kind of historical context is invaluable when writing software. By observing how a piece of code has changed over time, you can build a better understanding of the purpose it serves, and put yourself in the right mindset to change it.

Example Project

For a very simple, introductory example to this style of programming and writing, take a look at how I solved a simple code kata in literary commit style.

This is a very basic example, but I hope it serves as a clear introduction to the style. I plan on continuing to release literal commit posts over the coming months. Hopefully this intentional style of programming can be as helpful to other as it has been to me.

While I’m not advocating using literary commits in real-world software, in my limited experience, it can be an incredibly useful tool for honing your craft.