ezyang’s blog

the arc of software bends towards understanding

November, 2014

Tomatoes are a subtype of vegetables

Subtyping is one of those concepts that seems to makes sense when you first learn it (“Sure, convertibles are a subtype of vehicles, because all convertibles are vehicles but not all vehicles are convertibles”) but can quickly become confusing when function types are thrown into the mix. For example, if a is a subtype of […]

  • November 14, 2014