Reading Code Is Harder Than Writing It

It's funny that computer languages are the only languages where one learns to write before learning to read. It's actually not uncommon for people to never really learn to read code. This seems a little unbalanced given that we actually read code much more frequently than we write it.

Even those who promote software as a craft sometimes fall into the trap of often talking about writing clean code that people can read, yet not placing much emphasis on the skill of reading the code.

The ability to read code must also be a skill, and as such it must be something that can be learnt and practiced. In this presentation, we're going to look at:

- The different reasons we might have to read code, and how that should impact our reading
- The problems we face when reading code (even our own!)
- Tips to bear in mind when we're reading code
- Tools we can use to help our understanding
- How and where to practice these skills

At the end of the talk we will at least have considered whether we need to level up our "Reading Code" skill.

Transcript

1. Trisha Gee Lead Developer Advocate, Gradle @trisha_gee trishagee.com Reading Code is Harder Than Writing It
2. • Lead Developer Advocate • Java Champion & JetBrains Community Contributor • 20+ years development experience • Author Trisha Gee
3. Room on the Broom Julia Donaldson & Axel Scheffler
8. READING CODE
16. Why do we read code?
18. “Every programmer occasionally, when nobody’s home, turns off the lights, pours a glass of scotch, puts on some light German electronica, and opens up a file on their computer. They read over the lines, and weep at their beauty….” https://www.stilldrinking.org/programming-sucks
24. What are the problems?
26. “This file is Good Code. It has sensible and consistent names for functions and variables. It’s concise. It doesn’t do anything obviously stupid…. It reads like poetry written by someone over thirty.” https://www.stilldrinking.org/programming-sucks
42. “Real stupidity beats artificial intelligence every time.” Hogfather Terry Pratchett
44. Tips
46. “After enough exposure with feedback, your brain began detecting patterns and underlying structures, without your conscious awareness. With more exposure, your brain finetuned its perception and eventually figured out what really mattered. Your brain was making finer distinctions and sorting signal from noise even if you couldn’t explain how.” Badass: Making Users Awesome Kathy Sierra
47. Where to practice • Your codebase • Open source • Libraries you’re using • Coding katas
49. Don’t Judge • Explore • Make notes • Questions • Discoveries • Assumptions • Draw diagrams • Don’t change the code
51. Twelfth Night William Shakespeare
52. Structure • Services • Modules • Packages • Layers • Patterns • Naming • Relationships • Responsibilities • Data flow • Build order
55. “If music be the food of love, play on, Give me excess of it; that surfeiting, The appetite may sicken, and so die.” Twelfth Night William Shakespeare
56. Whylom, as olde stories tellen us, Ther was a duk that highte Theseus; Of Athenes he was lord and governour, And in his tyme swich a conquerour, That gretter was ther noon under the sonne. The Canterbury Tales, and Other Poems Geoffrey Chaucer (1387–1400)
57. Cantar de mio Cid Composed sometime between 1140 and 1207
58. Consider • Language • Libraries • Age • Patterns • Standards • Code shape • False friends
64. IDE Navigation https://youtu.be/1UHsJyCq1SU
65. Open it in your IDE
67. “If you don't think about the underlying mechanics of the simulation—even if that thinking happens in a semiconscious way—you won't last very long in the game. You have to probe to progress.” Everything Bad is Good for You: How Popular Culture is Making Us Smarter Steven Johnson
68. Run code to understand it • Code analysis tools • Debugger • Watches • Evaluate expression
70. “The game scholar James Paul Gee breaks probing down into a four-part process, which he calls the ‘probe, hypothesize, reprobe, rethink’ cycle” Everything Bad is Good for You: How Popular Culture is Making Us Smarter Steven Johnson
73. “It may, or may not, have helped Anathema get a clear view of things if she’d been allowed to spot the very obvious reason why she couldn’t see Adam’s aura. It was for the same reason that people in Trafalgar Square can’t see England.” Good Omens Neil Gaiman & Terry Pratchett
74. Tips 1. Practice 2. Reading is not reviewing 3. Code bases have a shape 4. Code bases have a dialect 5. Code is not linear 6. Code is meant to be run 7. If you must write, write tests 8. If you must change it, throw it away 9. Not all knowledge can be codified
79. “I’m grizzly and grumpy and grouchy and grumbly I’ve not been called lovely before!” The Giant of Jum Elli Woollard & Benji Davies
81. Conclusion
85. Donald Knuth – Literate Programming (1984) Code should be written to be read and understood, not just executed. Steve McConnell – Code Complete (1993) Developers spend more time reading code than writing it. Raymond Chen – Microsoft Developer Blog (2007) "Code is read much more often than it is written, so plan accordingly." Robert C. Martin (Uncle Bob) – Clean Code (2008) “Indeed, the ratio of time spent reading versus writing is well over 10 to 1.” Daniel Roy Greenfeld “Code is read more than it is written.” ChatGPT
89. “My fingers,” said Elizabeth, “do not move over this instrument in the masterly manner which I see so many women’s do. They have not the same force or rapidity, and do not produce the same expression. But then I have always supposed it to be my own fault — because I will not take the trouble of practising.” Pride & Prejudice Jane Austen
90. http://bit.ly/reading_code