On Wednesday, 19 October 2016 06:33:09 UTC-4, Jan Mercl wrote: > > On Wed, Oct 19, 2016 at 12:27 PM T L <tapi...@gmail.com <javascript:>> > wrote: > > Nothing. The language specification does not mention it. > > People use that term based on definitions specified for other programming > languages, but those are not always equal to each other. >
Jan is write that the term does not appear in the spec, but I think it's possible to come up with a useful definition of a reference type that applies to all ALGOL-like languages: a reference type is one whose values indirectly refer to mutable state. So, pointers are obviously references, as are slices, maps, and channels. But a string is not a reference because, although internally it contains a pointer, you cannot mutate the array of bytes to which it refers. Functions may be references, because a closure may refer to lexically enclosing variables. Structs and arrays are references if their elements contain references. An interface value is a reference if its payload contains a references. The essence of a reference is that copying one creates a new alias for its underlying state, and changes made via one alias are visible to all others. This definition is not absolute: a pointer to an immutable data structure, for example, can be considered to have "value" (non-reference) semantics since although it points to a variable, that variable can never be changed. -- You received this message because you are subscribed to the Google Groups "golang-nuts" group. To unsubscribe from this group and stop receiving emails from it, send an email to golang-nuts+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
