Recently, I've been playing around on Rosetta Code [1]. A Python guy posted a
new task:
http://rosettacode.org/wiki/Words_Of_Equal_Characters
What is the shortest possible J expression to solve this task? Here,
"shortest" means the minimum number of essential (required) characters. Right
now, I have:
>(#~[:(=>./)#&>)(</.~[:i.~/:~&.>)<;._2 toJ fread
jpath'~temp\unixdict.txt'
+-----+-----+-----+-----+-----+
|abel |able |bale |bela |elba |
+-----+-----+-----+-----+-----+
|alger|glare|lager|large|regal|
+-----+-----+-----+-----+-----+
|angel|angle|galen|glean|lange|
+-----+-----+-----+-----+-----+
|caret|carte|cater|crate|trace|
+-----+-----+-----+-----+-----+
|elan |lane |lean |lena |neal |
+-----+-----+-----+-----+-----+
|evil |levi |live |veil |vile |
+-----+-----+-----+-----+-----+
which is shorter than the original Python solution, but not dramatically
shorter. Is there a way to code this to really show off J's power? I'm more
focused on the aspect that produces the result given a list of words, rather
than the aspect that generates the list of words from the text (i.e. I'm
seeking to minimize the code to the left of the cut).
-Dan
[1] Rosetta Code is what it sounds like -- a chrestomathy site where
programmers are invited to solve programming tasks using different languages,
to build up a "Rosetta Stone" for different programming languages.
Of course, the primary motivation for posting a solution to Rosetta Code is not
to teach others your language, or to make it easier for a maintenance
programmer to convert a legacy system from COBOL to Perl. Those are just side
effects. The primary motivation for posting a solution to Rosetta Code is to
brag. It's main constituency is evangelists. It's the premier public
programming pissing match.
One drawback of Rosetta Code is that only the results of the programmer's
efforts are visible; there's no way to tell how long the solution took, or how
the language enabled the programmer to reach the solution. So even though this
solution (the "obvious way") took me less than a minute to write, no one
reading the page will know that. The only opportunity to "wow" the audience is
with a succinct, elegant solution. And since most of the audience won't be
able to read J, elegant is less important than succinct. That's why I'm
seeking an impressively short solution to this task (which seems right up J's
alley).
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