“Erlang has single-assignment variables. As the name suggests, they can be given a value only once. If you try to change the value of a variable once it has been set, you’ll get an error.”
(“Single-assignment variables” are the same as val fields in Scala. Using them can make your code more like algebra.)
Joe Armstrong, in his book,
Programming Erlang: Software for a Concurrent World
(Scala comment added by me)
“In Erlang, processes share no memory and can interact with each other only by sending messages. This is exactly how objects in the real world behave.”
Joe Armstrong, in his book,
Programming Erlang: Software for a Concurrent World
“Processes interact by one method, and one method only, by exchanging messages. Processes share no data with other processes. This is the reason why we can easily distribute Erlang programs over multicores or networks.”
Joe Armstrong, in his book,
Programming Erlang: Software for a Concurrent World
“In Erlang (Akka), it’s OK to mutate state within an individual process (actor), but not for one process to tinker with the state of another process.”
In Joe Armstrong’s book,
Programming Erlang: Software for a Concurrent World
(with Akka notes added by me)
“Everyday life is like programming, I guess. If you love something, you can put beauty into it.”
~ Donald Knuth
This is a good post from 2014 titled, 44 engineering management lessons.
Tried to use someone’s software library.
Documentation was bad, couldn’t get it to work.
Used someone else’s.
#haiku-ish
“If testing costs more than not testing, don’t test.”
~ Kent Beck (via this twitter page)
“Program testing can be used to show the presence of bugs, but never to show their absence.”
~ Edsger Dijkstra
A visual image of the mathematical concept of “sets” using southern colloquialisms.
(I found this image on Twitter, but since I didn’t “like” it at the time I can’t find who created it, but I’ll link to them if/when I ever find the page again.)
Here’s a link to an article titled, Little’s Law- An insight on the relation between latency and throughput.
As a note to my future self: Take time to think!
*sigh*
Even at my advanced age, if I don’t think through an algorithm I can still waste an awful lot of time.
As an example I just started working on a complex algorithm for my Android football game based on the initial thoughts in my brain, and came to regret it. After recovering from that faux-pas I decided to write just a few simple notes like this to clarify my thoughts:
I spent some time last night reading the book, Practical Common Lisp. In all Lisp books you’ll read about S-expressions, but very few authors explain what they are. This image comes from this Wikipedia page, which states, “In computing, s-expressions (for “symbolic expression”) are a notation for nested list (tree-structured) data, invented for and popularized by the programming language Lisp, which uses them for source code as well as data. In the usual parenthesized syntax of Lisp, an s-expression is classically defined as a) an atom, or b) an expression of the form (x . y) where x and y are s-expressions.” See that link for more information about Lisp and S-expressions.
I’ve been interested in the Lisp programming language since I first learned about it, but in the books I’ve read about it, no author has explained the background of terms like cons, car, cdr, and S-expressions. Tonight I found this “History of Lisp” document, which explains the meaning of some of those names.
(If you’re really interested in those terms, this Wikipedia page describes them even more.)
“Perhaps the most important principle for the good algorithm designer is to refuse to be content.”
~ Alfred Aho
(a very relevant quote for me today, from this twitter page)
“Besides a mathematical inclination, an exceptionally good mastery of one’s native tongue is the most vital asset of a competent programmer.”
~ Edsger Dijkstra
Chapters from The Handbook of Applied Cryptography are available from the publisher and authors as PDFs at this link.
“Years ago I knew little, but was comfortable using things I didn’t understand. Now I’m experienced, I fear things unless I understand them.”
“The universe is built up into an aggregate of permanent objects connected by causal relations that are independent of the subject and are placed in objective space and time.”
~ Jean Piaget
I can’t agree with the “permanent objects” phrase, but this is a quote from the book, Implementing Domain-Driven Design, by Vaughn Vernon
“The honest answer to almost any question in software development is, ‘It depends.’”
Eric Evans, author of Domain Driven Design
