added documentation for all functions

line.go

@@ -5,20 +5,26 @@ import (
 	"math"
 )
 
+// line is described as two Points
 type line struct {
 	pt1, pt2 Point
 }
 
-func lineHelper(l line) (float64, float64, float64) {
+// determinants aids by calculating necesary values for performing
+// calculations using the determinant of two points
+func determinants(l line) (float64, float64, float64) {
 	a := l.pt2.Y - l.pt1.Y
 	b := l.pt1.X - l.pt2.X
 	c := a*l.pt1.X + b*l.pt1.Y
 	return a, b, c
 }
 
+// lineIntersection returns the Point of intersection between two lines.
+// lineIntersection will only return a point if the point lies on the
+// line, otherwise it will return a nil point and an error
 func lineIntersection(l1, l2 line) (Point, error) {
-	a1, b1, c1 := lineHelper(l1)
-	a2, b2, c2 := lineHelper(l2)
+	a1, b1, c1 := determinants(l1)
+	a2, b2, c2 := determinants(l2)
 	det := a1*b2 - a2*b1
 
 	if det != 0 {
@@ -37,6 +43,7 @@ func lineIntersection(l1, l2 line) (Point, error) {
 	return Point{}, fmt.Errorf("lines do not intersect")
 }
 
+// lineOnLine determins if both points of a line, l1, are on the same line, l2
 func lineOnLine(l1, l2 line) bool {
 	if onLine(l1.pt1, l1.pt2, l2.pt1) && onLine(l1.pt1, l1.pt2, l2.pt2) {
 		return true