babjo

# Define a procedure, add_to_index,
# that takes 3 inputs:

# - an index: [[<keyword>,[<url>,...]],...]
# - a keyword: String
# - a url: String

# If the keyword is already
# in the index, add the url

babjo

# Define a procedure, lookup,
# that takes two inputs:

# - an index
# - keyword

# The procedure should return a list
# of the urls associated
# with the keyword. If the keyword

babjo

# Define a procedure, add_page_to_index,
# that takes three inputs:

#   - index
#   - url (String)
#   - content (String)

# It should update the index to include
# all of the word occurences found in the

babjo

def crawl_web(seed):
    tocrawl = [seed]
    crawled = []
    index = []                   
    while tocrawl:
        page = tocrawl.pop()
        if page not in crawled:
            content = get_page(page)           
 add_page_to_index(index, page, content)

babjo

def get_all_links(page):
    links = []
    while True:
        url, endpos = get_next_target(page)
        if url:
            links.append(url)
            page = page[endpos:]
        else:
            break

babjo

# Define a procedure, factorial, that takes a natural number as its input, and
# returns the number of ways to arrange the input number of items.

def factorial(n):
    if n == 0 :
        return 1
    else:
        return n * factorial(n-1)

babjo

# Define a procedure is_palindrome, that takes as input a string, and returns a
# Boolean indicating if the input string is a palindrome.

# Base Case: '' => True
# Recursive Case: if first and last characters don't match => False
# if they do match, is the middle a palindrome?

def is_palindrome(s):
 if s == '':

babjo

public Future<String> calculateAsync() throws InterruptedException {
    CompletableFuture<String> completableFuture = new CompletableFuture<>();
 
    Executors.newCachedThreadPool().submit(() -> {
        Thread.sleep(500);
        completableFuture.complete("Hello");
        return null;
    });
 
    return completableFuture;

babjo

Future<String> completableFuture = 
  CompletableFuture.completedFuture("Hello");
 
// ...
 
String result = completableFuture.get();
assertEquals("Hello", result);

babjo

public Future<String> calculateAsyncWithCancellation() throws InterruptedException {
    CompletableFuture<String> completableFuture = new CompletableFuture<>();
 
    Executors.newCachedThreadPool().submit(() -> {
        Thread.sleep(500);
        completableFuture.cancel(false);
        return null;
    });
 
    return completableFuture;