Digital Digressions by Stuart Sierra
From programming to everything else
Despite all of the AJAX/Web 2.0 hype, the fact remains that most web pages are mostly static. The most efficient way to serve static pages is unquestionably to store them as static files on a file-based web server such as Apache. I add new pages to this site once every few days at most, but…
Fiddling with some Common Lisp code a few weeks ago, I needed to push items onto the end of a list. After thinking for a moment, I wrote this: (defun push-end (object place) (nconc place (list object)) Since I was fiddling in LispWorks at the time, I discovered that LispWorks already defines its own push-end…
Every programming language has idioms–patterns used so frequently that they are almost considered part of the language itself. (See these C idioms for examples.) Common Lisp, with almost unlimited possibilities for syntax, depends more heavily on idioms to remain comprehensible. Some examples are defsomething or define-something for definitions, something-p for predicate tests, and make-something for…
A common complaint about Object-Oriented Programming (OOP) is that classes can make simple data hard to deal with: “I don’t want a DirectoryList object, I just want a list of strings.” I would say this is not a flaw inherent in OOP but rather in the way it is commonly used. “Encapsulation” and “data hiding”…
In Common Lisp, you can’t do this: (defgeneric g (x)) (defmethod g ((x (and integer (satisfies evenp))) …) Because (and integer …) is not a class. It is a valid type specifier and thus could be used in declarations, but it cannot be used in a method argument list. It’s fairly easy to see why…
Playing with the first in a (hopefully ongoing) series of Common Lisp Quizzes, I wrote a simple text-only CAPTCHA (completely automated public Turing test to tell computers and humans apart). My solution and others are posted at CL Quiz #1. CAPTCHA> (generate-captcha) “You started out with forty-nine Lisp Machines. Not through any fault of your…
Steve Oualline wrote a nifty little Perl program to graph regular expressions. And Oliver Steele wrote an even niftier OpenLaszlo app to show how regular expressions work. Together, they make the best (unintended) argument I’ve seen for visual programming languages. As Oualline writes in his article, “Humans can process images far faster and better than…
Just recently discovered the E Programming Language. Very interesting concept. It’s nice to see a something growing out of the Algol/C/C++/Java tree that improves the syntax. And a mainstream language that can handle concurrency well without blocks and locks is definitely needed. Making programmers deal with threads and mutexes is definitely too hard, just like…
Given the task of designing a programming language, which must be exactly defined for engineering purposes, what would a linguist — as opposed to a mathemetician — do?
In looking around the offices where I have worked, I see innumerable places where existing technology could be leveraged to expedite, simplify, or otherwise enhance day-to-day workflow. Things could happen faster, cheaper, with fewer staff. So why isn’t this done? I think there are two fundamental problems: The first is the disconnect between the potential…