Mauer-Oats 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 ([email protected]). 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

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

Keybase proof

I hereby claim:

I am maueroats on github.
I am maueroats (https://keybase.io/maueroats) on keybase.
I have a public key ASBPwMX19TZWUx07wMbKOclCTxGAUw-LGo2N4UJ55zb88Qo

To claim this, I am signing this object:

	#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.
	;;


	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


	(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)

	(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)