From https://en.wikipedia.org/wiki/Pure_function https://en.wikipedia.org/wiki/Pure_function: "the function return values are identical for identical arguments"

From https://en.wikipedia.org/wiki/Pure_function https://en.wikipedia.org/wiki/Pure_function: "the function return values are identical for identical arguments". The whole point of pure function is that the caller can understand its dependencies without looking at its implementation, because all dependencies are listed as parameters. You can redefine what "pure" means if you wish, but that pretty much defeats the purpose.