lib/geometry: document ILine

Signed-off-by: Jean Privat <jean@pryen.org>

diff --git a/lib/geometry/points_and_lines.nit b/lib/geometry/points_and_lines.nit
index 14a67fb..303aae1 100644 (file)
--- a/lib/geometry/points_and_lines.nit
+++ b/lib/geometry/points_and_lines.nit
@@ -55,9 +55,13 @@ end
 
 # An abstract 2d line segment
 interface ILine[N: Numeric]
+       # The type of points that ends the segment
        type P: IPoint[N]
 
+       # The point that is the left-end of the segment
        fun point_left: P is abstract
+
+       # The point that is the right-end of the segment
        fun point_right: P is abstract
 
        redef fun to_s do return "{point_left}--{point_right}"