Our experience on Day 0 of JPR11 yielded a nice example of the need to choose an appropriate implementation of an abstract concept. As I mentioned in the previous post, we experimented with Michael Barker’s Scala implementation of Guy Steele’s parallelizable word-splitting algorithm (slides 51-67). Here’s the core of the issue. Given a type-compatible associative [...]
Why should an object-oriented programmer care about tail-call elimination? Isn’t that just another esoteric functional programming concept? Maybe not. Back when dinosaurs roamed the earth, a common technique for performing a subroutine call worked this way: The caller stored the address at which it wished to resume execution in a known place (e.g. adjacent to [...]
Yesterday’s SICP study group call indulged briefly in the “why LISP hasn’t caught on” theme. I suggested that some programmers seem to have a limited tolerance for abstraction, and cited the well-known Primitive Obsession anti-pattern as evidence. One of the other participants (I’m sorry that I don’t know all the voices yet) challenged that statement. [...]
This month’s Memphis Java Users’ Group meeting featured Jesse Tilly of IBM Rational Software, who spoke to us on static analysis. He will be doing a more product-intensive session, “What is IBM® Rational® Software Analyzer® Telling Me?”, at the upcoming IBM Rational Software Conference. (Don’t be misled by all those “circle-R”s; I just linked to [...]
This post describes the first model in Haskell for the BuilderBuilder task. We will develop the model incrementally until we have rough parity with the Java version. I’m experimenting with ways to distinguish user input from system output in transcripts of interactive sessions. This time I’m trying color, using a medium blue for output. I [...]
The next step in the BuilderBuilder project is to develop a model in Haskell that is analogous to the Java model in the previous post. This post will introduce just enough Haskell to get started; the next post will get into the BuilderBuilder model. Environment: I’m using GHC 6.10.1, obtained from the Haskell web site. [...]
The “BuilderBuilder” posts will be my exploration of one question: “What does Functional Programming mean to me as a practicing OO software developer?” Despite contemporary buzz about how FP will save the world from bugs and single-threaded code, I don’t want to read (or write) another clever Fibonacci number generator, or another theoretical explanation of [...]
I commented elsewhere on how the “Architecture of Participation” idea may be percolating into the field of programming languages. I am especially interested in seeing whether the adoption of Scala provides evidence of this phenomenon. Scala is a strongly, statically typed language implemented on the JVM—all characteristics that raise eyebrows (if not noses) in some [...]
The fifth problem from Project Euler asks for “the smallest number that is evenly divisible by all of the numbers from 1 to 20″. The key, for me, was to paraphrase that as “the least common multiple of 1 to 20″. The least common multiple (lcm) of two natural numbers is their product divided by [...]
The fourth task from Project Euler is to find the largest palindrome that is a product of two three-digit numbers. (I’m assuming decimal. ) Name no one man The first sub-task is to determine whether the decimal representation of an integer is palindromic. A direct approach yields this: def reverseInt(n: Int) = { def rev(a: [...]
