Remove bad code from 13-year-old me

distance.go

@@ -0,0 +1,62 @@
+package main
+
+import "math"
+
+func Jaro(a, b string) float64 {
+	la := float64(len(a))
+	lb := float64(len(b))
+
+	// match range = max(len(a), len(b)) / 2 - 1
+	matchRange := int(math.Floor(math.Max(la, lb)/2.0)) - 1
+	matchRange = int(math.Max(0, float64(matchRange-1)))
+	var matches, halfs float64
+	transposed := make([]bool, len(b))
+
+	for i := 0; i < len(a); i++ {
+		start := int(math.Max(0, float64(i-matchRange)))
+		end := int(math.Min(lb-1, float64(i+matchRange)))
+
+		for j := start; j <= end; j++ {
+			if transposed[j] {
+				continue
+			}
+
+			if a[i] == b[j] {
+				if i != j {
+					halfs++
+				}
+				matches++
+				transposed[j] = true
+				break
+			}
+		}
+	}
+
+	if matches == 0 {
+		return 0
+	}
+
+	transposes := math.Floor(float64(halfs / 2))
+
+	return ((matches / la) + (matches / lb) + (matches-transposes)/matches) / 3.0
+}
+
+
+func JaroWinkler(a, b string, boostThreshold float64, prefixSize int) float64 {
+	j := Jaro(a, b)
+
+	if j <= boostThreshold {
+		return j
+	}
+
+	prefixSize = int(math.Min(float64(len(a)), math.Min(float64(prefixSize), float64(len(b)))))
+
+	var prefixMatch float64
+	for i := 0; i < prefixSize; i++ {
+		if a[i] == b[i] {
+			prefixMatch++
+		}
+	}
+
+	return j + 0.1*prefixMatch*(1.0-j)
+}