はてなブックマーク

I have started code reading groups at the last two companies I’ve worked at, Etsy and Twitter, and some folks have asked for my advice about code reading and running code reading groups. Tl;dr: don’t start a code reading group. What you should start instead I’ll get to in a moment but first I need to explain how I arrived at my current opinion. As a former English major and a sometimes writer, I h

21. Programming in the Large: Packages and SymbolsIn Chapter 4 I discussed how the Lisp reader translates textual names into objects to be passed to the evaluator, representing them with a kind of object called a symbol. It turns out that having a built-in data type specifically for representing names is quite handy for a lot of kinds of programming.1 That, however, isn't the topic of this chapter

19. Beyond Exception Handling: Conditions and RestartsOne of Lisp's great features is its condition system. It serves a similar purpose to the exception handling systems in Java, Python, and C++ but is more flexible. In fact, its flexibility extends beyond error handling--conditions are more general than exceptions in that a condition can represent any occurrence during a program's execution that

Greetings would-be Lisper, Due to a lack of mental and CPU cycles, I have not been able to keep up with producing up-to-date Lispboxen. Consequently the Lispbox distributions that used to be downloadable from here have become attractive nuisances—things that look like they'd be useful but mostly are not. But times have changed and there are every day better and better ways to get set up with Lisp.

3. Practical: A Simple DatabaseObviously, before you can start building real software in Lisp, you'll have to learn the language. But let's face it--you may be thinking, "'Practical Common Lisp,' isn't that an oxymoron? Why should you be expected to bother learning all the details of a language unless it's actually good for something you care about?" So I'll start by giving you a small example of

22. LOOP for Black BeltsIn Chapter 7 I briefly discussed the extended LOOP macro. As I mentioned then, LOOP provides what is essentially a special-purpose language just for writing iteration constructs. This might seem like a lot of bother--inventing a whole language just for writing loops. But if you think about the ways loops are used in programs, it actually makes a fair bit of sense. Any progr

8. Macros: Defining Your OwnNow it's time to start writing your own macros. The standard macros I covered in the previous chapter hint at some of the things you can do with macros, but that's just the beginning. Common Lisp doesn't support macros so every Lisp programmer can create their own variants of standard control constructs any more than C supports functions so every C programmer can write