♻️ HalfStepInt refactor

[hacheigriega]

♻️ Refactor

HalfStepInt was introduced to deal with possible half-step values (0.5) that might appear when we calculate the median of integers.

The current implementation of HalfStepInt uses a number of type T to represent the integer part of a number. However, this is more prone to an overflow while calculating the median than using uint64. The current implementation is also confusing in that the integer field and the neg field are both used to infer the sign of the number. This issue calls for refactoring the code so that it conforms to the following, more straightforward, type:

type HalfStepInt[T constraints.Integer] struct {
	integer  uint64
	neg      bool // if true, the integer is negative
	halfStep bool // if true, the number contains fractional part (0.5)
}

In addition, detect any possible overflow and handle it properly.