4 ms·

Depends on your brand of static typing.

• drdaeman 13y ago
  In fact, Erlang's records are something like this. They are tuples under the hood (with a first element being atom name of record "type"), and pre-processor translates matching properties by name to matching tuple elements in proper position. So, you can't made typo in this scenario - the code won't compile. I.e., you declare: -record(foo, {bar = ?default_bar, baz = ?default_baz}). And every time you write #foo{bar = 1} you get {foo, 1, ?default_baz} under the hood. Obviously, records are unusable as general-purpose dictionaries as they have fixed structure. One big inconvenience with records is the fact that you have to type record's name every single time you have to do anything with it. And writing MyFoo#foo.bar is cumbersome, compared to MyFoo.bar in most other languages. Another issue is that records exist only before pre-processing. Even compiler is unaware of member names, let alone the runtime. This makes introspection and live code operations (by connecting a shell to a running instance) quite inconvenient.
  • tel 13y ago
    It'll still yell at you for typos, though. You can confuse positional with nominal, but you can't make invalid nominal statements. Which is not at all to say that Erlang's tuple/record trick is anything but a clever trick. It is kind of neat to see how far you can go with just that, though.
  • lostcolony 13y ago
    The number of times I've had to type element(3, Record) (or whatever ordinal) for a filter/map, after manually -counting- the fields in the head of a list of records, because I didn't have the source with the record definition handy to rr() in my shell...