Duplicating code is acceptable, IMHO, if it is either clear the two files are going to diverge quickly, or if it looks like they will not be changed at all in t

Duplicating code is acceptable, IMHO, if it is either clear the two files are going to diverge quickly, or if it looks like they will not be changed at all in the foreseeable future. Trouble starts if there are two source files that do almost the same thing but slightly different, and then you need to change them; now you probably need to change these duplicate files in lock step, and that is a rather error-prone process. IIRC, this kind of problem was the reason for adding templates to C++. And say what you will about C++, but templates are a very powerful tool. I fail to see the connection to language design, though. Is the author saying that one should add some feature to make duplication as unnecessary as possible (like templates in C++)? Or that the tooling around the language should be better suited to automatic code generation? FWIW, I think code generation is a very powerful tool; in a way, code generation is meta-programming. (Is there a distinction at all?) And I think that there is a lot of potential in this area. Go has supported the "go generate" command for a while now, and I have seen a few very interesting use cases (e.g. ffjson, which generates code to serialize/parse Go data types to and from JSON more efficiently than the builtin reflection-bases mechanism). Someone once said (I forgot who), "I'd rather write programs that write programs than write programs." That sums it up pretty well, I think. ;-) Okay, okay, so now I do see the connection to language design. Sorry, my fingers were faster than my mind this time.