Lecture 3 - Page 21 : 42
Functional Programming in Scheme
Name 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
Example of recursion:
number-interval
The function
number-interval
returns a list of integers from a lower bound to an upper bound
(define (number-interval f t) (if (<= f t) (cons f (number-interval (+ f 1) t)) '()))
The function
number-interval
from the general LAML library. This function returns a list of
t-f+1
numbers from
f
to
t
.Try it out!.
The function
number-interval-iter
is an iterative, tail recursive variant of
number-interval
.
A sample dialogue with the number interval functions.
The append function
A list replication function
