Saturday, July 22, 2006

old smalltalkers considered useful

Thank you Joseph Moore for your endorsement of old Smalltalkers.

"Young whipper-snappers out there, take note: if you ever here some Old Dude say the words "in Smalltalk you could blah blah blah" or "In VisualWorks you could yada yada", spend as much time with this person as possible. "

Yes young grasshopper, listen to my rantings (thanks Joe, check's in the mail!)

Saturday, July 15, 2006

I don't understand...

Sympatico (my ISP) sent me an email telling me that
my "Sympatico e-mailbox is almost full" and that perhaps I should actually read my email so that my mailbox doesn't fill up.

Thanks for the tip. Here's one back - don't send me email to tell me my email box is full!

Friday, July 07, 2006

I wonder if we'll see him online...

I have one, Mike has one and now US president Bush has one.

My son can probably take him in Super Mario Kart ... I wonder if we'll see POTUS online via the Nintendo WiFi Connection ?

PowerpointUnit... the end of presentations as we know them

Steve Loughran making arguments for increased testing required for WS*.* interop was quoted in a few places with his well turned phrase "strategic glue for a planet". As least thats how I happened on his blog entry. Yes blah blah, more testing is good but I think the real innovation Steve made was his idea for empowering architects via PowerpointUnit...

"we could bring the tools to the architects with PowerPointUnit being a test framework combining powerpoint macros and the truth-resolution feature of the semantic web"

he nailed it... Made me laugh for sure and PowerpointUnit gets my vote for the killer app that would most change my life.

Tuesday, July 04, 2006

PHP, Smalltalk and Java... sorted out

The other day I needed to sort something... doesn't matter what, but it consisted of a collection of key/value pairs... The keys were strings and the values were integer strings (strings whose values were actually integers). The code happened to be in PHP and I had been outputting unsorted results. This started to bother me so I thought "how hard could it be to sort" ?

So, googled the API... (and found it's call sort ... duh!) and inserted a sort call into my code ...

sort ($table);

but nope, didn't work. It sorted by values but it didn't keep the keys like I needed but looky here, PHP has a rich library and a bunch of friendly sort routines including asort, which does exactly what I wanted - it sorts the values and keeps the keys which were indexing those values... sounds perfect ? sort of ... I also wanted it sorted from into descending values which was no problem either, arsort to the rescue, except one problem. It returned results that looked like like "30,20,100,1" which makes sense if you remember what I said about values being strings which looked like integers. These strings also had some leading blanks on the values due to being read from a file so they sorted kind of funny including the problem where 100 is between 20 and 1. One last tweak to the rescue, PHP has an option on the sort functions to treat values like integers.

The final code added was

arsort ($table, SORT_NUMERIC);

pretty sweet and not too much work for me. So for reference, a simple example in PHP looks like this.

$a = array ("a"=>"1","b"=>"2","c"=>"3","d"=>"4","e"=>"100");
arsort ($a, SORT_NUMERIC) ;

Every one knows Smalltalk is my favourite language, it's just done right... so how would it compare ?

Lets start with a table in array form which looks like this. I set it up so it matches PHP.

| table |
table := #(('a' '1')('b' '2')('c' '3')('d' '4')('e' '100')).

sorted as strings ...

(table asSortedCollection: [ :a :b |(a at: 2) > (b at: 2)]) asArray

-> (('d' '4') ('c' '3') ('b' '2') ('e' '100') ('a' '1'))

sorted as numbers ...

(table asSortedCollection: [ :a :b | (a at: 2) asNumber > (b at: 2) asNumber]) asArray

-> (('e' '100') ('d' '4') ('c' '3') ('b' '2') ('a' '1'))

Exactly what I wanted - properly sorted arrays, not too much code.

How about our old friend Java ? ... sigh ...

String[][] anArray = {{ "a", "1"},{"b","2"},{"c","3"},{"d","4"}, {"e","100"}};

and a print helper

private static void printArray(String[][] anArray, String message) {
for (String[] i : anArray) {
System.out.println(i[0] + " " + i[1]);

some snippets. Below is my first try, sure it compiles but it doesn't work.

System.out.println("This sort will runtime error... but compiles just fine.");
Arrays.sort(anArray); // type safety ? ha ! still get a runtime error ...
printArray(anArray, "Sorted using Arrays.sort no, extra comparator.");

Yes, I get a runtime error in the library when it does a cast to Comparable.

Exception in thread "main" java.lang.ClassCastException: [Ljava.lang.String; incompatible with

at java.util.Arrays.mergeSort(
at java.util.Arrays.sort(
at stringsort.Test.main(

Indeed, type safety is not a catch all, runtime errors are still possible (remember that kids when you try to tell your boss it compiled so it's gotta work). In fact, don't forget to mention cases like this to people who don't understand #doesNotUnderstand:

To fix, you add a comparator. Pretty simple (but blocks are simpler).

class CompareAsStrings implements Comparator {
public int compare(String[] a, String[] b) {
return b[1].compareTo(a[1]);
}} ;

and the code looks like this

Arrays.sort(anArray, new CompareAsStrings());
printArray(anArray, "Sorted using CompareAsStrings");

of course the output is string sorted (and wrong for what I want).

Sorted using CompareAsStrings
d 4
c 3
b 2
e 100
a 1

so instead of this, you add a compatator which converts to Integers.

class CompareAsInts implements Comparator {
public int compare(String[] a, String[] b) {
return new Integer(Integer.parseInt(b[1])).compareTo(new Integer (Integer.parseInt(a[1])));

and you finally get happy sorted values...

Sorted using CompareAsInts
e 100
d 4
c 3
b 2
a 1

Of course some bozo is gonna tell me that they would have created a class for the key/value pairs which would have implemented comparable and all would have been fine. Yes, and it would have been a page of code.

So, what do you learn from this ... nothing really, just some random ranting about Java verbosity but if you're the lesson learning type...

Lesson #1 Wanna be agile ? Write less code, use a dynamic language like Smalltalk or PHP.
Lesson #2 Never trust the compiler despite how type safe it claims to be.

happy birthday north america

It's a long weekend of birthdays...

Last Saturday it was Canada Day, celebrating confederation, July 1, 1867. Happy 139 Canada.

Today, is Independence Day in the USA, celebrating 230 years since tea taxes enraged the people to form their own country (and some other reasons too).

You may also be interested to know that Canadians owe some of their independence to the thrifty British and the warmongering Americans...

In fact, the Canadian goverment web site confederation information for kids teaches our kids that these very facts.

I quote ...
"Meanwhile, Britain didn't want to have to pay for the cost of defending its colonies. It decided to encourage the colonies to join together, because the United States would be less likely to attack Canada if it were a self-governing country rather than separate colonies of Britain. The fear of the United States helped to strengthen the call for Confederation."

Thank you cheap British people and you Americans for the threat which helped encourage us Canadians into Confederation.
One more thing, ummm, Americans, please don't plan to attack us again and no quebec does not have the bomb despite what the simpsons say....

Just us peaceful Canadians up here... Feel free to come up and join us for the fishing.