9999999999999999.0 – 9999999999999998.0

I don't understand all the crap that IEEE 754 gets. I appreciate that it may be surprising that 0.1 + 0.2 != 0.3 at first, or that many people are not educated about floating point, but I don't understand the people who "understand" floating point and continue to criticize it for the 0.1 + 0.2 "problem." The fact is that IEEE 754 is an exceptionally good way to approximate the reals in computers with a minimum number of problems or…

> That Go uses arbitrary-precision for constant expressions seems dangerous to me. I'm somewhat baffled by this statement. If a Go program compared a constant expression float against a runtime computed float, it could have unexpected results, but comparing floats in general is dangerous. I don't see how this language quirk increases that danger in a meaningful way.

Isn't it an expected behaviour (at least for programmers) because of IEEE 754? For example, in Racket this also gives 2.0, but if you are using exact numbers (#e), then it gives exact and correct answer 1.0. Same for Java (and any other language): if you are using Float/Double numbers, then you are loosing precision. Use BigDecimal (or something similar for other languages) if you want exact calculations.