maueroats

AP CS A Draft Framework Feedback

This document contains the comments from one detailed read-through of Unit 1 of the AP CS A Framework Draft. If you would like help understanding it or carefully reading the rest of the document, please contact Andrew Mauer-Oats (maueroats@gmail.com). I am a computer science teacher at Whitney M. Young Magnet High School in Chicago. At this point my document is not carefully proofread, but I hope it conveys the important ideas.

• 1.4.A.1 System.out.print: including output is a change from the past. Why not stick with function return values? That would be "testable" (e.g. JUnit).
• 1.4.B. String is a data type. It should be in 1.3. Having two definitions to arrive at "string literal" seems a waste. How about none, the way it is for double? Escape sequences are ok to include.
• 1.4.C. There should be an analog for String expressions, at least mentioni

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#lang racket/base

;; This file is placed in the public domain.

;; Version 1.5 Added testable version. Now add space only when needed. Related bugs fixed.
;; Version 1.4 Remove duplicate source code from gist.
;; Version 1.3 Get characters directly, per suggestion of Laurent O.
;; Version 1.2 Suggestions by Laurent O: help, menu, url2script-info.
;; Version 1.0 Initial release.
;;

maueroats

Types for Nonempty Lists

This is a writeup of the issues I found changing the type signatures of max and min to require at least one input. The idiom of applying these functions to "rest" args means a number of other type signatures need to be enhanced to propagate assurances that list are nonempty.

Discussion

maueroats

from typing import TextIO

# Problem: produce the dual graph for a triangulation

## This file contains the triangle parsing code.

example_triangulation = '''
VERTICES 4
0.000000 240.000000 0.000000

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(ql:quickload :lisp-unit)
(use-package :lisp-unit)
(setf *print-failures* t)

(defun one-more-mult (n)
    "* Make sure you know how to use (mod x n) to figure out if x is
divisible by n. Write a function that takes in an integer and returns
true when the integer is one more than a multiple of 8."
  nil)

maueroats

(declaim (optimize (debug 3)))
(ql:quickload :lisp-unit)
(use-package :lisp-unit)
(defparameter *print-failures* t)

(defun mappend (f xs)
  (apply #'append
         (mapcar f xs)))

(defun demo (x)

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