I may have created a few impure properties in the past, but it might be a good default recommendation not to do that.

in my glm port, I have

Float.rad

to convert deg->rad,

Float.sin

and

.cos

, etc.. do you consider it bad?

No, not at all. Why would you think so? These are pure functions.

an example of those impure properties?

Impure functions are those with implicit dependencies, i.e. may not return the same value for given set or arguments.

now

is a good example, but anything non-purely functional really, like using

Random().newInt()

inside such functions.

I still think

sin(x)

makes more sense for pure functions because thats the default mathematical syntax, you never see

x.sin

out there

@minivac yeah, you are right, but I find it somehow attractive because it has no parenthesis and it kind of follow the logic flow of "taking x and calculate sin"