School Is Hell

It was only last week when a student was arrested for writing an essay, and a few weeks ago when another innocent kid was thrown into jail because of a Daylight Savings Time bug.

now a student has been arrested for making a video game map of his school, something that is apparently quite common for people learning to make video game maps. Now granted, I can see how fuddy-duddy grown-ups with no understanding of video games might be freaked out by a kid (look out, he’s Asian!) playing what appears to be a simulation of himself running around shooting inside his school. But any sane school administrator will simply talk to the kid and see if anything’s up, as opposed to searching the kid’s house and arresting him when they find a hammer, which he apparently needed to fix his bed.

My high school wasn’t much better. When I was a junior, several kids got caught with marijuana. In addition to getting the DEA involved, the administration told some of the kids that if they ratted out their friends, they would get suspended and not expelled. They ratted and got expelled anyway. This was not lost on the rest of us kids, nor our younger siblings, nor their friends… the administrators completely alienated their students as well as future students by betraying their trust. I don’t see this getting better any time soon.

–YY

p.s. As a bonus, here’s an excellent essay by Paul Graham: Why Nerds Are Unpopular: “If life seems awful to kids, it’s neither because hormones are turning you all into monsters (as your parents believe), nor because life actually is awful (as you believe). It’s because the adults, who no longer have any economic use for you, have abandoned you to spend years cooped up together with nothing real to do. Any society of that type is awful to live in. You don’t have to look any further to explain why teenage kids are unhappy.”


Ruby Tip – Cleaner Object Inspection

Here’s a cute tip I picked up in Ruby a little while back. Ruby has some nice built-in inspection methods that let you discover some things about an object. The public_methods method will list all the public methods for a particular object:


irb(main):001:0> ''.methods
=> ["methods", "instance_eval", "%", "rindex", "map", "<<", "split", "any?", "du
p", "sort", "strip", "size", "instance_variables", "downcase", "min", "gsub!", "
count", "include?", "succ!", "instance_of?", "extend", "downcase!", "intern", "s
queeze!", "eql?", "*", "next", "find_all", "each", "rstrip!", "each_line", "+",
"id", "sub", "slice!", "hash", "singleton_methods", "tr", "replace", "inject", "
reverse", "taint", "sort_by", "lstrip", "frozen?", "instance_variable_get", "cap
italize", "max", "chop!", "kind_of?", "capitalize!", "scan", "select", "to_a", "
each_byte", "type", "casecmp", "gsub", "protected_methods", "empty?", "to_str",
"partition", "tr_s", "tr!", "match", "grep", "rstrip", "to_sym", "instance_varia
ble_set", "next!", "swapcase", "chomp!", "is_a?", "swapcase!", "ljust", "respond
_to?", "between?", "reject", "to_s", "upto", "hex", "sum", "class", "method", "r
everse!", "chop", "", "insert", "<", "tainted?", "private_methods", "==", "de
lete", "dump", "===", "__id__", "member?", "tr_s!", "unpack", ">", "concat", "re
quire_gem", "nil?", "untaint", "succ", "find", "strip!", "each_with_index", ">="
, "to_i", "rjust", "<=", "send", "display", "index", "collect", "inspect", "slic
e", "oct", "all?", "gem", "clone", "length", "entries", "chomp", "=~", "public_m
ethods", "upcase", "sub!", "squeeze", "__send__", "upcase!", "crypt", "delete!",
"equal?", "freeze", "object_id", "detect", "require", "zip", "[]", "lstrip!", "
center", "[]=", "to_f"]

Above is an array of every method available for a String object. It’s useful, but if you’re trying to track down the name of a particular method, it’s going to be hard to find. So the first step is to use sort on the resulting array:


irb(main):003:0> ''.public_methods.sort
(Picture the same output as above, but sorted ;-)

Better, but we still have a lot of inherited methods that aren’t specific to Strings, like object_id, clone, and inspect (not to mention public_methods itself). How do we filter those out? With the reject method:


irb(main):014:0> ''.public_methods.reject {|m| Object.methods.index(m)}.sort
=> ["%", "*", "+", "<<", "[]", "[]=", "all?", "any?", "between?", "capitalize",
"capitalize!", "casecmp", "center", "chomp", "chomp!", "chop", "chop!", "collect
", "concat", "count", "crypt", "delete", "delete!", "detect", "downcase", "downc
ase!", "dump", "each", "each_byte", "each_line", "each_with_index", "empty?", "e
ntries", "find", "find_all", "grep", "gsub", "gsub!", "hex", "index", "inject",
"insert", "intern", "length", "ljust", "lstrip", "lstrip!", "map", "match", "max
", "member?", "min", "next", "next!", "oct", "partition", "reject", "replace", "
reverse", "reverse!", "rindex", "rjust", "rstrip", "rstrip!", "scan", "select",
"size", "slice", "slice!", "sort", "sort_by", "split", "squeeze", "squeeze!", "s
trip", "strip!", "sub", "sub!", "succ", "succ!", "sum", "swapcase", "swapcase!",
"to_f", "to_i", "to_str", "to_sym", "tr", "tr!", "tr_s", "tr_s!", "unpack", "up
case", "upcase!", "upto", "zip"]

The result are String-only public methods. Notice the list is much shorter (49 fewer methods, to be exact).

One more step: if you want to filter out any inherited methods (not just Object’s), use superclass:


irb(main)> class A; def a; end; end;
irb(main)> class B < A; def b; end; end
irb(main> B.instance_methods.reject {|m| Object.methods.index(m)}
=> ["b", "a"]
irb(main)> B.instance_methods.reject {|m| B.superclass.instance_methods.index(m)}
=> ["b"]

In this contrived example, A is a class with one method (a), and B is a class inherited from A with its own method (b). If you filter out Object’s methods from B’s, it shows a and b. If you filter out A’s methods from B’s, it only shows b.

I should just point out that I used instance_methods, not methods or public_methods, since a and b are both instance methods, and would not show up in B.methods. If I made an instance of B (using B.new), then it would show up for that.

Whew! Hope this helped somebody…

–YY


Vista Breaks Everything

Here’s a whole writeup on just how bad Vista is, due its built-in DRM systems. In a nutshell problems crop up on multiple levels (software, hardware, performance, reliability), and the costs associated with those problems are all passed on to the consumer. Monitors and soundcards stop working, for example, because Vista is going out of its way to make them stop working. Stay away…

–YY