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There's nothing similar about Java's and Go's interfaces, except the name. Java interfaces must be implemented explicitly (they're nominal). Go interfaces are

• twic 3y ago
  They are certainly different, but to say there is nothing similar is plainly untrue - apart from nominal vs structural, they are pretty much the same. I'm not sure how significant the nominal vs structural distinction even is. In Go, a struct can implement an interface without declaring it, but the programmer still needs to deliberately write the struct to conform to the definition of the interface, so they're still coupled, just not explicitly [1]. Yes, it is possible to define a new interface which fits existing structs which weren't designed for it - but how common is that? That is, how common is it for two or more structs to have a meaningful overlapping set of methods without being designed to conform to some pre-existing interface? [1] which is obviously a bad thing
• dwattttt 3y ago
  Go's nominal interface feature is definitely interesting, but that section doesn't talk about how amazing it was to implement interfaces implicitly: > That notion quickly grew into the idea that value types had behaviors, defined as methods, and that sets of methods could provide interfaces that functions could operate on. Go's interfaces arose pretty much right away. If you replace Go with Java, this would've accurately described Java ~30 years ago.
  • tomp 3y ago
    You missed this: > Making interfaces dynamic, with no need to announce ahead of time which types implement them
    • moomin 3y ago
      Yeah, they managed to recreate the advantages and disadvantages of Modula-3's typing system within three decades. Groundbreaking.
• marwis 3y ago
  Scala had it 2 years before golang, OCaml more than decade. https://en.wikipedia.org/wiki/Structural_type_system https://en.wikipedia.org/wiki/Structural_type_system
• Izkata 3y ago
  So they're like python's Abstract Base Classes? (No idea which came first)