/*
Implemented as state.boost() * lengthNorm(numTerms), where numTerms
is FieldInvertState.length() if setDiscountOverlaps() is false, else
it's FieldInvertState.length() - FieldInvertState.numOverlap().
*/
func (ds *DefaultSimilarity) lengthNorm(state *index.FieldInvertState) float32 {
var numTerms int
if ds.discountOverlaps {
numTerms = state.Length() - state.NumOverlap()
} else {
numTerms = state.Length()
}
return state.Boost() * float32(1.0/math.Sqrt(float64(numTerms)))
}