Anatomy of a Thirty-five-year Mistake – Casey Muratori (BSC 2025) / HN

The most treacherous metaphors are the ones that seem to work for a time, because they can keep more powerful insights from bubbling up. - Alan Kay (1984)

Unified function call: The notational distinction between x.f(y) and f(x,y) comes from the flawed OO notion that there always is a single most important object for an operation. I made a mistake adopting that. It was a shallow understanding at the time (but extremely fashionable). Even then, I pointed to sqrt(2) and x+y as examples of problems caused by that view. - bjarne

Entity Component System (ECS)

Looking Glass (1998)

• the opposite of a fat-struct
• Architecture care about encapsulation boundaries
  • where you make it difficult to access things
  • vs where you make it easy
• Encapsulation boundaries around the system vs Boundaries accross the objects
• don’t make the domain model be in the code.
  • compile-time hierarchy of encapsulation that matches the domain model => Are not that good (and may be counterproductive).

OOP

• oop was just about passing message - (Alan Kay)
• inheritance hierarchy was told early (since 1980s)
  • C++ does not force to do it that way (even if it promoted it a lot)
• Stroustrup 1994 (Design of Evolution of C++) - C++ on simula -> didn’t scale
  • Simula build was very long / incremental build suck
  • Simula runtime was very slow (because of the GC even when no work was needed)
  • about large Teams (were hierarchy and encapsulation should strive) => didn’t work even on 1 people team
  • inheritance used mainly for code-reuse
  • INSPECT from simula was explicitly not ported to C++ - forcing latter usage of virtual function (vs discriminated union)
• Team Fat Struct Founded 1960
  • Dougals T. Ross (struct(plex) + vtable)
• Ivan Sutherland’s SketchPad (1963) - probably the most significant thesis ever done - Alan Kay (1987)
  • ring structured designed to rapid constraint satisfaction - chicken - a link in the linked list that point to the sentinel (hen)
  • the virtual function was the least interessting part of this (because it was possible because draw was very simple) - the constraint solver was omniscient (ECS model)
• CSG on Spheres (1997) - NegaMan (Negative Metaball)
• Mixin vs Pattern
• Fat struct vs ECS - Ultima underworld used Fatstruct for entity
  • how to compact memory and avoid overlap (handle fuel & damage)?
  • avoid fragmentation
  • arbitrary sized properties
  • types at run time
  • how fast is the fastest case

see also

• Switching away from OOP
• The Only Unbreakable Law
• Where Does Bad Code Come From?