19 Sunday Apr 2020
Tags
code clarity, computer programming, operator precedence, order of operations, parentheses, readable code, software design
Enough stories, time for a new rule. Which is to always use parentheses in all except the simplest of math expressions. Languages have a precedence protocol, so the compiler can figure it out, but human readers may be confused.
As always, the underlying motivation involves code clarity for other humans reading the source code — the most important rule of all.
23 Sunday Jun 2019
Tags
There’s a fairly simple puzzle, called The Eight Queens, that I’ve long favored as a project for first semester CS students. The problem is simple enough for a beginner to tackle, yet also interesting enough to be engaging. (And just tricky enough to be a nice beginner challenge.)
Due to a discussion on my other blog, I dug out an old Python implementation I had, and, after looking at it, I thought it might be worth writing a post about. If nothing else, as I said, the problem is interesting enough to be engaging.
14 Tuesday May 2019
Posted in CS101
I’m returning to the full-adder logic circuit modeling to present the code for a version that tries to capture the timing of the signals.
The goal is to take a closer look at the intermediate states of the adder as signals trickle through it.
08 Wednesday May 2019
This is the third post in the Full Adder series. The first post explored ways to code the abstract model of a full-adder. The second post explored one way to code a simulation of a physical system (where the models are of the components of the system).
This post explores another gate-based model, but one with only one type of gate. This simulation is close to being transistor-level.
07 Tuesday May 2019
In the last post, I explored different ways to model the logic of a full-adder. In this post I’ll explore a model of a physical instance of a full-adder — a model that simulates physical reality.
Because a full-adder is, at root, a mathematical expression, various software models can accomplish the same results. Models are abstractions, so the only thing a model can simulate perfectly is another model.
05 Sunday May 2019
Posted in CS101
Tags
finite state machine, FSA, FSM, full adder, half adder, Python code, state engine, state table, truth table
I was involved in a debate recently about whether a full adder logic circuit is a computer. The computer science answer is: “No, not as we define a computer.”
I plan to address that answer in detail on my main blog. Here I wanted to show some of the different ways a full adder can be modeled and implemented.
19 Monday Dec 2016
Posted in CS101
Tags
computer language, computer languages, computer programming, computer science, GOTO statement, iteration, language design, loop statements, programming language, recursion
When it comes to what makes a computer (or any other) language a programming language, there are three characteristics usually required:
This post is just a brief note (for a friend) about the third item and why it allows three distinct options.
16 Tuesday Aug 2016
Posted in CS101
Tags
constants, defined values, global constants, literal values, literals, named constants, named values, numerical constants, P.J. Plauger, string constants
Along with “always use less-than” is another great piece of always advice, except this one is a prohibition, a never rather than an always (same thing, really, from a programmer’s point of view).
It has to do with never having literal values embedded in your code!
08 Monday Aug 2016
Posted in CS101
In his brief 1982 essay (EWD831), computer science giant Edsger Dijkstra examines a topic that (inappropriately, as it turns out) vexes some programmers: Why in the world do computer people count starting at zero? Everyone knows that counting starts at one!
As it turns out, there are two very good reasons for counting from zero!
06 Saturday Aug 2016
Posted in CS101
Tags
computer language, computer languages, computer programming, computer science, language design, programming language, Turing complete
Back in the post HTML is not a programming language! I brought up the three properties required by a programming language. A discussion recently got me thinking about it again. This post is just some notes on those thoughts…
The Hard-Core Coder 