Style guidelines for cs1321x
----------------------------

o Unless otherwise noted, all assignments should be written in R5RS
  scheme.

o When saving, save files as plain text.  Do not use comment boxes or
  insert pictures or any of the other options under "special".  This
  will cause your file to be saved in an unreadble, non-plaintext
  format.

o Wrap lines at no more than 80 (eighty) characters.  You can tell how
  far along you are so far by looking at the little box at the bottom
  of the DrScheme editor window.  The number on the left of the colon
  is the line that you're on, and the number on the right of the colon
  is the horizontal position on the line.  Don't let the number on the
  right (the horizontal position) go over 80.  

o Let DrScheme indent the file.  Make it look pretty to read.

o When writing functions, make sure that you name your function
  exactly as specified in the homework, and that your function has its
  parameters in the correct order.  

o Use the standard scheme convention for comments--two semicolons to
  begin a whole-line comment and a single semicolon for inline
  comments.  

o For each function that you write, you should have a header that
  gives the contract and purpose.  For example:

;; contract factorial: non-negative-number -> number
;; purpose given a non-negative number, return the factorial of that
;; number
(define (factorial num) 
   ( ...

o Give your functions descriptive names.  If your function only
  returns #t or #f, end the name with a question mark.  Remember that
  longer is not always better--conciseness counts!

o When naming parameters you should use concise names.  Make them short
  enough to be usable but long enough to be meaningful.  Avoid
  single-character variable names.  

o When writing a helper function, give the function a meaningful name.
  If it sums a list then 'sum-list' is a good name.  'add-em-up' is
  not quite as good.  'do-it' is unacceptable.  'bob' will get you
  negative points.  If the helper is just for tail recursion, then
  just add '-tail' to the end of the function name (ie, factorial and
  factorial-tail)