Geometric abstractions

Haggis depends on a number of geometric abstractions that are documented here:

• Coord: 2D points.
• Rectangle: Operations over sets of points lying inside a rectangle with sides parallel to the X and Y axes.
• BoundingBox: Computing the extent of geometric shapes.
• Transform: 2D transexampleion matrices.
• Interval: Int intervals.
• Geometry: Geometric requirements.
• CompassDirection: Direction type.
• BasicTypes: Some very basic types.