          Lecture 3 - Page 26 : 42
 Functional Programming in SchemeName binding, Recursion, Iteration, and Continuations * Name binding constructs The let name binding expression The equivalent meaning of let Examples with let name binding The let* name binding construct An example with let* The letrec namebinding construct LAML time functions * Conditional expressions Conditional expressions Examples with if Example with cond: leap-year? Example with cond: american-time Example with cond: as-string * Recursion and iteration Recursion List processing Tree processing (1) Tree processing (2) Recursion versus iteration Example of recursion: number-interval Examples of recursion: string-merge Examples with recursion: string-of-char-list? Exercises * Example of recursion: Hilbert Curves Hilbert Curves Building Hilbert Curves of order 1 Building Hilbert Curves of order 2 Building Hilbert Curves of order 3 Building Hilbert Curves of order 4 A program making Hilbert Curves * Continuations Introduction and motivation The catch and throw idea A catch and throw example The intuition behind continuations Being more precise The capturing of continuations Capturing, storing, and applying continuations Use of continuations for escaping purposes Practical example: Length of an improper list Practical example: Searching a binary tree
 Hilbert Curves
 The Hilbert Curve is a space filling curve that visits every point in a square grid

 To see this image you must download and install the SVG plugin from Adobe.In Firefox please consultthis page. A hilbert curve of order 5 which is traversed repeatedly to emphasize the maze. The view enforced on you through this picture is an iterative one: We traverse the curve one edge after the other. Needless to tell, this gives a very confusing and complicated understanding of the curve. Below, we will explain the curve in recursive terms. It turns out that this will be key to understanding the curve. Relative to the Scheme program shown later, this curve is produced by the call (hilbert 5 'up) .
 The path taken by a Hilbert Curve appears as a sequence - or a certain iteration - of up, down, left, and right.
 Recursion - an ECIU material