4 ms·

Where was pre-Java 1.5's generic HashMap? Or closures?

• pjmlp 12y ago
  > Where was pre-Java 1.5's generic HashMap? In java.util.Hashtable as implementation of the java.util.Dictionary interface, since version 1.1 back in 1997. Implemented using s/interface{}/Object/g with ability to use any type as key, as long as, hashCode() and equals () are overriden. Also allows for fine tuning of the capacity and load factor. > Or closures? In anonymous inner classes. A pain to use when compared with real closures, but doable nonetheless.
  • masklinn 12y ago
    In the discussion's context, "generic" is about parameterized types (type-safe collections), not about working on any object.
    • pjmlp 12y ago
      Which Go lacks and the OP was stating it has.
      • masklinn 12y ago
        * Go has a generic hashmap, the builtin map type is one of the magical special-status generic collections (with arrays, slices and channels). * pre-1.5 Java did not have one, its only parametric type was the low-level array
        • pjmlp 12y ago
          Ah, ok. That is correct.
  • burntsushi 12y ago
    That is not a generic HashMap. See masklinn's response. The fact is, the comparison between Go and "pre generics Java" is a bad one. There are many substantial differences, and blessed parameterized types in Go is absolutely one of them.