MEPX
Chapter 5 of 10All chapters
  1. 1Reading is the job
  2. 2Getting oriented
  3. 3Understanding a function
  4. 4Following state
  5. 5Recognising shapes
  6. 6Reading for trouble
  7. 7Using history
  8. 8Tests as documentation
  9. 9Taking notes
  10. 10Reading in review

Chapter 5 of 10

Recognising shapes

Most code is familiar underneath.

Common structures

Loops that filter, map or accumulate. Guard clauses. Retry loops. Caches. Once you recognise the shape, you can skim it and focus on what is unusual.

  • The unusual part is where the bug and the domain knowledge both live.
  • Repeated near-identical blocks are worth noting: they drift apart over time.

Idioms differ

Every language and codebase has conventions. Learning them is quick and turns puzzling lines into background noise.