And in 1981 there were already application servers, running in multiprocessor machines using Multics, UNIX and VMS, just to name a few operating systems.
By placing the contract at the use of a type with an interface rather than at the declaration of a type you effectively introduce a form of duck typing to a static language.
You can write an interface for a type long after the type has been declared (or been declared by someone else). Interfaces can be defined and used without having to go back and change existing code. This is very lightweight.
They are if you put the words "easily, efficient programming of" in front of them, which I think was what the parent comment was getting at.
To be even more pedantic than yourself, I would like to point out that everything that can be expressed is an idea. For us to have a word we must have a meme. A noun and the idea of a noun are inseperable. Even mathematics is language that conforms to this rule.
Point taken. Mine is that Go attempts to solve these new ideas with 1980s programming language technology. Touting it as a reimagining of C (or anything) would be insulting to C.
Dismissing Go as '1980s programming language technology' is unfair, patronising and misses the point.
Very little of substance has been invented in programming languages since Lisp was created in the 1950s. It has mostly been syntax.
C itself is an early 1970s language based on ideas from the 1960s. It has been the backbone of serious computing for nearly 40 years. It is 1970s programming technology that works.
One of the few 'new' things to arrive was Tony Hoare's CSP (in 1978). Go takes this idea and builds an effective implementation of it onto a C-like language with minimal noise.
Go then adds the a tiny amount of syntax to C to have a layer of Object Orientation. This is not a 'modern' 1980s style of OOP like C++ uses, rather it is the 1970s OOP of Alan Kay and Smalltalk.
So it it insulting to say that 'Go attempts to solve these new ideas with 1980s programming language technology'.
D took C++ and improved upon it.
Go went back to C and said, "what if C++ had never existed".