[burntsushi]

The context of this discussion started when people were complaining about the language designers being able to build in special functions that are type parametric. The implication was: if the language designers can do it, why won't they allow me to do it?

i.e., purity for purity's sake. It ignores legitimate trade offs between allowing a few special functions and building an entire generics system into the language.

[kenko]

I still don't know what you mean by "purity". Saying "i.e., purity" doesn't help, since I already knew that you think purity has something to do with generics being definable by people other than the language designers.

"If the language designers find it useful to occasionally use type-parametric functions, why won't they recognize that other people might also find it useful, too, and for other functions?" doesn't strike me as a demand for purity in any sense. Consistency, maybe; recognition that the designers are giving themselves special treatment, sure. What's pure about the desired state of affairs, or impure about the present?

Honestly, sometimes it seems as if someone who wants to defend Go against a criticism immediately claims that the critic is just obsessed with purity. Why else would you criticize Go?

[burntsushi]

This was the original comment that I responded to:

> and having the interpreter get special status in breaking them, see generics

It's a whine that the interpreter gets "special status." It's implicit in the complaint that special status is somehow bad. It ignores any trade offs that go into the design decision.

Purity in this context means: the language gets no extra special power that users of the language can't tap into themselves.

> Honestly, sometimes it seems as if someone who wants to defend Go against a criticism immediately claims that the critic is just obsessed with purity.

And sometimes it seems as if someone criticizes Go just because they are obsessed with stuffing as many features as possible into a programming language. Shit happens.