Bloat

John C. Dvorak asks the following in his latest blog entry:

But I wonder if all open-source projects will eventually go the way of all software. Upgrade after upgrade adds more and more complexity, to the point where the software begins to get bogged down under its own weight. How many open-source projects have you seen in which the code gets leaner and meaner rather than fatter and fatter?

Good question. Software becoming more complicated and bigger is almost a universal truth. I don't see why open-source should be immune. Of course, the more features you add, the bigger your program will become. But, even software that is being maintained becomes an entangled network of goo. Brian Foote even wrote an anti-pattern about it called "Big Ball of Mud".

This is the problem that needs to be solved. I see a huge focus on creating tools that allow quick creation of code. But, I see few dealing with complexity of existing code and even dismissal of the ones that do exist. Refactoring tools are mandatory in the fight against creeping code. Tools that allow diagnosis of live running systems is a must. Code generation gets my code out the gate quicker, but without a gym, it becomes slow as molasses as the race continues down the path of new features.

I want to create systems that in their evolutionary cycle grow consistently with new features. The complexity should be in line with features. Right now, this becomes exponential and is proven by ever rising maintainance costs. Our current weapons are refactoring tools, code checkers (lint), metrics, debuggers, and let's not forget the most important: education. Actually, could that be the answer? Discipline and education just don't have the same kind of sexy ring to them, but tools can only take you so far. Still anything that can help our brains reel in the complexity is a welcome addition. Software is only going to get more complex as we go along. I think we spend so little time on reducing complexity in existing code because the feedback is not immediate. I want to get to the point where I can deliver the third version as fast I delivered the first.

It's a shame with all of the advances in our field that we have been unable to keep maintainance costs down. There are developers working on this problem. I've heard rumblings that tools are in the works. One possibly being a more macro level refactorer. I can't wait to use it. Until then, I'll keep my lint, refactorer, inspector, debugger, and metric runner close by my side. If anyone has any other tools that they like to use to keep complexity down, I would love to hear it. My brain can always use help.

I'll end with this all too true quote on Firefox in the same article as mentioned above:

Just look at Firefox, one of the poster children for open source. It loads more slowly than ever. It will be on some page within a tab, and that page will be refreshing ads or something in the background, and Firefox just hangs all its cycles there, slowing down the whole computer. Every couple of days the browser is hogging cycles, and I have to go to the Task Manager and kill it. Other people have this problem, too.

Go read the rest of the article. He makes some good points on mindless fans of technologies. Sadly, I think open-source is going to be the place where the tools to deal with complexity will be born. Until then, open-source will suffer the same as the rest of us with bloat.

"Considered Harmful" Considered Harmful

It's official. "Considered harmful" can be added to list of cliches to avoid. It needs to go into retirement along with factorial and prime examples.

Debuggers...again

Giles Bowkett recently asserted: Debugger support considered harmful. It seems this has been going around for years. See this old post of mine: Am I a Bad Programmer?. Nothing new. The assertion is that if you have tests, you don't need a debugger. Interesting. I'm heavy into testing my code. Anything I write even for fun has a test to go with it. And yet, I still use my debugger quite a bit.

Why? Well, it depends on what I'm doing. I use the debugger for exploratory programming, when sinking into the depths of someone else's code (especially if they didn't write tests), during code reviews, and when faced with a nasty bug. Even though I write my code in small pieces (small classes and small methods), I am not perfect. When everything is combined and put into production, strange things happen to my code. The code doesn't change; the environment does. A situation occurs that I didn't think of and thus it is not tested. This is the realm of the debugger especially if the bug is nasty and hard to find. Any piece of complex software has these hidden. We are human. Let's embrace that. A world without debuggers is a weird sci-fi perfect world with monsters lurking beneath the surface.

Debuggers are great for exploratory programming when you are just trying out a new framework and seeing how it works. I like to walk line by line. I did this when I was learning Seaside and it was better than any documentation. Besides, watching beautiful code unfold in your debugger is nothing short of reading a great book. And when you're dealing with some ugly code, a debugger has shown me things that my eyes deceived me on when just looking at the code. Why dissect the dead animal when I can see how its organs work while it is still alive?

An expressive debugger saves time as well. I remember when I came back to Smalltalk after doing Java for several years. I had forgotten that you never need to restart your programs. I wrote a simple Seaside application and only restarted the web server once. I coded live in the system and when I saw a problem (that my tests didn't catch) in the debugger, I could change it right there. It was amazing.

I guess all of this talk of no debuggers or that debuggers is a crutch for bad developers. It can enable the "get it running once" mentality instead of thinking of all the cases and your design. Like any tool it can be abused, but that doesn't mean we should get rid of all tools. Duck typing can be abused as well and I wouldn't trade it for the world.

StAX Tomorrow Night

I'll be giving a short talk at the Omaha Java User's Group tomorrow night. It will cover the StAX API that's new to Java 6. StAX is the streaming counter-part to SAX. I'll probably also touch on a little bit of API design too.

Omaha Dynamic Language Group

Erlang is the hottest new language in the land to learn. It's what on the tip of everyone's tongue. Why is it so hot? What makes it so special? I am proud to have Erlang guru Sam Tesla presenting to answer all our questions. He will be displaying why Erlang scales so well and it's many unique features. This will be one meeting that should not be missed!

And if that wasn't enough, we have none other than Tek Systems providing all of the pop and pizza that our bellies can take. Prepare to have your mind and stomach stuffed!

Come out and join us for the best user group in the land (In my opinion, of course).

Topic	A Gentle Introduction to Erlang
Speaker	Sam Tesla
Time	October 2, 7-9pm
Location	UNO's Peter Kiewit Institute (PKI) building 1110 South 67th Street Omaha, NE

Good Design

I love Alex Ruiz's post on named parameters in Java. Why? For one, it shows how he got around Java's lack of named parameters. He then goes on to explain why he made the design choices he made. Pros and cons are then listed for the approach. But, the part that I loved is that he sided on the side of the API user. It made his life as the API designer harder and cost him more code to write. The result was something that allowed for more readable code for the client. I love it! I tend to design with making the client's life easier instead of mine. This article is excellent for outlining the design choices and not being dogmatic. Everything is logical and well laid out. Another reason I loved the article is that the lack of a language feature inspired him to work harder to get the same result. A post that inspires us to push for better solutions no matter the constraints.

I'm embarrassed

I can't believe what gets passed off as humor these days. I'm embarrassed to be part of a community where one of the main evangelists of the community post such bile and garbage. It was meant to be funny. But, calling developers outside your community "morons" even in jest is not cool. It certainly doesn't breed communication and good will. And if you were interested in "making the world of software development a more enjoyable, productive place", then name calling is not the way to do it. I understand it was done in humor and I know you are writing off my serious reply as "dumb" because of your debate killing "if you didn't get the humor, then you're dumb" post. But, if you wanted to be funny, you went about it the wrong way. All you displayed was a level of immaturity that should be unacceptable in our community. It wasn't witty.

And to end I will add, yes, Ruby does need tools. It needs tools badly. I would love to have refactoring support (that works) and a good debugger. I can't imagine doing a project of any size without those tools. Not every one is a great developer and eventually you will step into some unsavory code. Tools are for helping with those unsavory pieces of code and even to gain understanding on a large system. This is where learning comes in. Instead of writing the developer off as a "moron", I use unsavory code and tools to teach how to do it better. So, who's really "making the world of software development a more enjoyable, productive place"?

A Sorting Language

Inspired by Neal Ford's post on patterns and sorting in Ruby:

class Comparator
  def initialize(&default)
    if (defined? default)
      @compare_block=default
    else
      @compare_block=lambda { |a,b| a <=> b }
    end
  end
  
  def compare(a,b)
    @compare_block.call(a,b)
  end
  
  def to_proc
    method(:compare).to_proc
  end
  
  def to_comparator
    self
  end
  
  def then_by(next_aspect)
    next_comparator=next_aspect.to_comparator
    self.class.new do |a,b|
      comparison=compare(a,b)
      if (comparison == 0)
        next_comparator.compare(a,b)
      else
        comparison
      end
    end
  end
  
  def reverse
    self.class.new do |a,b| 
      comparison=compare(a,b)
      if (comparison == 1)
        -1
      elsif (comparison == -1)
        1
      else
        0
      end
    end
  end
end


def by(aspect_to_compare)
  aspect_to_compare.to_comparator
end

class Symbol
  def to_comparator
    Comparator.new { |a,b| a.send(self) <=> b.send(self) }
  end
end

module Enumerable
  def to_comparator
    inject do |thus_far, every|
      thus_far.to_comparator.then_by(every.to_comparator)
    end
  end
end

require 'rubyunit'
class SortTest < Test::Unit::TestCase
  def test_simple
    a=Person.new("blaine", 36)
    b=Person.new("blaine", 12)
    
    result=[a,b].sort(&by(:name).then_by(:age))
    assert_equal([b,a], result)
  end
  
  def test_array
    a=Person.new("blaine", 12)
    b=Person.new("alice", 12)
    
    result=[a,b].sort(&by([:age, :name]))
    assert_equal([b,a], result)
  end
  
  def test_reverse
    a=Person.new("grue", 123)
    b=Person.new("thief", 34)
    
    result=[a,b].sort(&by(:name).reverse)
    assert_equal([b,a], result)
    
    result=[a,b].sort(&by(:age).reverse)
    assert_equal([a,b], result)
  end
end

class Person
  attr_reader :name, :age
  
  def initialize(name, age)
    @name=name
    @age=age
  end
end

I loved Neal's post, but it got me thinking that sometimes I need to sort beyond one field. How could I go about that? I whipped up this example really quick. The function :by is simply syntactic sugar for converting to a comparator. I thought it read better. Neal's solution is the way to go if you need to sort on a single field. But when you need more, the above will work too. This is another one of my little late night coding thoughts. Enjoy.

Duh....

pdcawley wrote the following comment to my previous "reduce" post:

[1,2,3,4].inject() {|a,b| a + b} # 10

So, I looked it up in ri and got this entry:

------------------------------------------------------ Enumerable#inject
enum.inject(initial) {| memo, obj | block } => obj
enum.inject {| memo, obj | block } => obj
------------------------------------------------------------------------
Combines the elements of _enum_ by applying the block to an
accumulator value (_memo_) and each element in turn. At each step,
_memo_ is set to the value returned by the block. The first form
lets you supply an initial value for _memo_. The second form uses
the first element of the collection as a the initial value (and
skips that element while iterating).

# Sum some numbers
(5..10).inject {|sum, n| sum + n } #=> 45
# Multiply some numbers
(5..10).inject(1) {|product, n| product * n } #=> 151200
javascript:void(0)
# find the longest word
longest = %w{ cat sheep bear }.inject do |memo,word|
memo.length > word.length ? memo : word
end
longest #=> "sheep"

# find the length of the longest word
longest = %w{ cat sheep bear }.inject(0) do |memo,word|
memo >= word.length ? memo : word.length
end
longest #=> 5

Ouch. All that coding for nothing (well, I did get to play around with some stuff). Next time, I will consult the documentation before I post. Duh...Good call.

P.S. It seems Rails implements the Symbol extension of #to_proc already. It's in the activesupport stuff. Their implementation is similiar to mind. But, I found one implementation better than mine. I love reading other people's code because it always shows me things I didn't think of. For your reading pleasure:

class Symbol
  def to_proc
    lambda do |this, *arguments|
      this.send(*arguments)
    end
  end
end

This is better than using shift and cleaner. I got this from one of the comments off of Neal Ford's blog. Great stuff.

More Functional Fun In Ruby

I have no clue whenever this will be useful, but it was a fun exercise. Hope you enjoy it as well. It's an implementation of Lisp's cons, car, and cdr.

def pair(left,right)
  lambda do |dyadic|
    dyadic.call(left,right)
  end
end

def left(pair)
  pair.call(lambda {|left,right| left})
end

def right(pair)
  pair.call(lambda {|left,right| right})
end

require 'rubyunit'

class WorkspaceTest < Test::Unit::TestCase
  def test_simple
    a_b=pair('a','b')
    assert_equal('a',left(a_b))
    assert_equal('b',right(a_b))
  end
  
  def test_again
    a_b=pair('a', 'b')
    c_a_b=pair('c', a_b)
    assert_equal('c', left(c_a_b))
    assert_equal('a', left(right(c_a_b)))
  end
end

Python's Reduce, (Fun)ctional Programming, and Ruby

Mike Hostetler blogged about Python's reduce. He said he never had a use for it until recently. I looked at his example and I thought that looks a lot like inject, but it uses the first element in the collection as the seed instead of it being given. I thought what mad fun would it be to write one in Ruby? Exactly. Here's my implementation:

module Enumerable
  def reduce(empty_return=nil, &dyadic)
    to_execute=lambda do |thus_far,every|
      to_execute=dyadic
      every
    end
    inject(empty_return) do |thus_far, every|
      to_execute.call(thus_far,every)
    end
  end
end

require 'rubyunit'

class ReduceTest < Test::Unit::TestCase
  def test_simple
    result=[1,2,3,4,5].reduce {|thus_far,every| thus_far + every}
    assert_equal(15, result) 
  end
  
  def test_empty_nil
    result=[].reduce {|result,every| thus_far + every}
    assert_nil(result)
  end
  
  def test_empty_default
    result=[].reduce(0) {|result,every| thus_far + every}
    assert_equal(0, result)
  end
end

It has a somewhat functional style in that instead of using a boolean to check for the first iteration, I just use a special lambda for the first pass and then it turns itself into the original one. There is some state (to_execute), but I'm still a functional newbie.

I do love inject, which has a lot of uses beyond aggregation, and this will reduce (no pun intended) code in some places where I use it.

Anyway, I couldn't stop myself. I thought wouldn't it be nice to just pass in a symbol instead of a block? I added the following method to Symbol and another test. Check it out:

class Symbol
  def to_proc
    lambda do |*arguments|
      arguments.shift.send(self, *arguments)
    end
  end
end

class SymbolTest < Test::Unit::TestCase
  def test_simple
    result=[1,2,3,4,5].reduce &:+
    assert_equal(15, result) 
  end
end

All I do is take a list of arguments. I make the first one the receiver and send the rest as it arguments. How cool is that? I get to cut down on the line noise. I still have to put up with &, but until they make blocks first class citizens...

What's the point of this post? Nothing. Just wanted to do a fun little exercise. I thought others might find the implementation fun as well. Now, about that name 'reduce'...I think maybe aggregate would be better? But, that doesn't express for all cases either. Hmmm...

Why Is Groovy So Slow?

Peter Knego wonders "Why Is Groovy So Slow?" and shows some evidence. I will admit I expected Groovy to be slower than Java because even though it does compile to Java byte codes. It has to perform various translations to satisfy the VM that expects a lot to be already typed. The Java VM is an ugly world for dynamic languages because of the early bind nature to gain performance. Some of his numbers were shocking. He also mentioned he was going to run numbers on jRuby as well. I'll be curious about that too. I'm expecting the numbers to tell a similar story.

But, that's not the point of this post. I'm worried with posts like the above because developers will use it as evidence that you shouldn't use dynamic languages. I never thought the arguments for not using dynamic languages would be played out again. Back in the 90's, it was Smalltalk vs. C/C++. I remember having many a debate how the productivity gains out weighed the small performance hit for late binding. I thought when Java won, I would never have to argue about performance ever again.

It's not that the above posts are bad. I think they are wonderful. It gives something that the Groovy guys can use to make their product better. And that's good for all of us wanting to be dynamic in a static world. But, those numbers will also be used to prove why you shouldn't use dynamic languages. And that's sad. It's all come full circle. I hope I am wrong, but I doubt it. The numbers are not bad because dynamic languages are slow, but because trying to get them run on an architecture not built with them in mind.

We Need Each Other: Ruby and Smalltalk

Neal Ford made a blog post on meta-programming, Ruby, and Smalltalk recently. It caused some discussion from long-time Smalltalker, James Robertson, and Rubyist, Glenn Vandenburg. Even Avi Bryant got in the discussion. There was a lot of talking past one another on the issues of code generation in Ruby and Smalltalk.

I'll start with a quote from Neal Ford:

the Smalltalk version is a great example of accidental complexity, not essential complexity.

There is no example given of what the "accidental complexity" was in Smalltalk. But, let's look at an example that Rubyists are familiar with and then I'll go forward:

class Person
  attr_accessor :name
end

This will generate the accessors :name and :name= at run-time. It's a nice way to describe a public field. There's even read and write only variations. It allows you to describe your intent of the field. Now, in Smalltalk you could do the same thing with class-side methods. Like so:

attributeAccessors
    ^#(name)

This could add the instance variable (if it didn't exist), and generate the getters and setters when the class is initialized. It is true in this case, we would use tools to do the generation and generate the code before hand. I think this is what Neal was talking about accidental complexity because we are adding methods that we later have to browse through. But, this is where they are mistaken.

Smalltalk has categories and usually, these code generated methods are placed in them. Accessors are generally placed in their own category so do not add to the cognitive friction. In fact, when I use code generation, I group the methods in a category with "AUTO" in it. This is so that I can later delete those methods and start over. Also, it allows me to not have to look at them when looking at the more important methods of the class.

There is one last way to do things like this in Smalltalk, but is rare. Classes are created in Smalltalk by sending messages. It's not some hard-coded construct in the language. It's a message. We can create our own messages to create our own classes. Here's what the example could look like in Squeak:

Object subclass: #Person
 attributeAccessors: 'names'
 classVariables: ''
 poolDictionaries: ''
 category: 'MetaExample'

And lastly, there is a initialize method for all Smalltalk classes that would give a more Ruby feel:

initialize
    self attributeAccessors: 'name'

Now, with all of that said, these are just examples to show what is possible. It's all a matter of taste and what you are trying to accomplish to which method you choose.

finally, my mouth dropped when I saw this in the same blog post:

Smalltalk had (and has) an awesome environment, including incredible tool support. Because the tool is pervasive (literally part of the project itself), Smalltalkers generally shied away from the kind of meta-programming described above because you have to build tool support along with the meta-programmed code. This is a conscious trade off. One of the best things about the Ruby world (up until now) is the lack of tool support, meaning that the tools never constrained (either literally or influentially) what you can do. Fortunately, this level of power in Ruby is pretty ingrained (look at Rails for lots of examples), so even when the tools finally come out, they need to support the incredible things you can do in Ruby.

I will answer this as bluntly and respectively as I can. Smalltalkers have NEVER shied away from meta-programming because of having to build a tool. Most Smalltalkers have a bag of tools that they use and add to their environment. Tools are so easy to write in Smalltalk that most programmers in it have at some point written one or two to help them. It's trivial to add functionality to the browser and inspectors. Generally, Smalltalkers only stay away from things that are hard to debug (ala method_missing, doesNotUnderstand:), but do them when necessary. Readability is always the utmost importance to Smalltalkers. Abbreviations are generally frowned upon even.

The last thing I want to remark on is the quote in bold above. I'll repeat it here because it makes me both shocked and sad:

One of the best things about the Ruby world (up until now) is the lack of tool support

I hardly call that a strength. Really. Why would I want to go back to bear skin and stone development? I have finally become productive in Java because of Eclipse (code browsing, auto-format, code completion, refactoring, etc). Why would I want to go back to command line brute force methods? I keep hoping for a great Ruby IDE (some are close like Ruby's Eclipse plug-in, Arachno, etc). Besides, I think while tools like ri and rdoc are nice, I want to look at source code and it's difficult to find the definitions of methods (without using grep) when going through new source code. A friend once told me he never trusted a language you couldn't write an IDE for it. There's truth to that. I never got FreeRIDE to last longer than a few minutes of development. Tools and easy to read syntax are necessary.

Ruby has great potential, but the syntax needs to be heavily reafactored (%w while being nice shorthand is unreadable) and made more consistent (blocks do not take the same types of arguments as methods, I can not send a block with & into a block example, lambda {|&block| block.call } gives a compile error). But, those are my gripes and I do still like Ruby. I think boasting that your language has no tools is short sighted at best.

I think both Smalltalk and Ruby developers could learn a lot from one another. So, if any Ruby developer has questions about Smaltallk, please feel free to email me. I will even extend the same to Smalltalk developers curious about Ruby. The point of this post was mainly to educate and inspire both Rubyists and Smalltalkers to be better.

Omaha Dynamic Language Group

Pinch me. Our speaker this month is none other than "Mister Groovy Eclipse Plug-In" Scott Hickey. He will be speaking about Rexx though. Rexx is a little known scripting languages with some unique features. This should be an incredible talk to make you think about Rexx in a totally different light. I can not wait.

I hope to see everyone there!

Topic	Rexx: The Little Known Scripting Language
Speaker	Scott Hickey
Time	September 4, 7-9pm
Location	UNO's Peter Kiewit Institute (PKI) building 1110 South 67th Street Omaha, NE

String Concatenation

I made a small mistake in the code in "Promises and String Concatenation". The DelayString object not being stateless is a huge problem. Here's the test to prove it:

    def test_independence
      first = "3" + "4"
      second = first + "5"
      third = "2" + second
      assert_equal("34", first.to_s)
      assert_equal("345", second.to_s)
      assert_equal("2345", third.to_s)
    end

Ouch. I fixed it by making DelayString only know a left and a right part. It cleaned the code up quite a bit. I factored out Promise because it made the code a little less readable. The resulting code is much simpler:

class DelayString

  def initialize(oneString, anotherString)
    @left = oneString
    @right = anotherString
  end  

  def +(another)
    DelayString.new(self, another)
  end

  def to_s()
    return @result unless @result.nil?
    to_process=[self]
    @result=String.stream_contents do |out|
      until (to_process.empty?)
        current=to_process.pop
        current.process(to_process,out)
      end
    end
  end  

  def process(to_process,io)
    to_process.push(@right)
    to_process.push(@left)
  end  

end



class String

  def self.stream_contents(&monadic)
    StringIO.open() do |io|
      monadic.call(io)
      io.string
    end
  end

  def +(another)
    DelayString.new(self, another)
  end

  def process(to_process,io)
    io << self
  end

end

All of our tests run. DelayString is stateless (minus caching of the result). There's still improvements to be made, but the code is simpler and easier to understand. The performance did take a hit. It's twice as slow (43.94s) as the previous version. Not to worry it still beats normal concatenation by a large margin. I'll take the performance hit for more readable code anyday!

Promises And String Concatenation

You've read about it a million times. Beware of multiple string concatenations. They make your code slow and consumes memory. You've read it in the Java books (known as "use StringBuilder or StringBuffer instead of +"). But, why? Why isn't this handled at a lower level? Why can't the VM or compiler just do the right thing?

Messages are the power of objects. So, why not make a new object that when sent the + message, it simply returns an object that waits to do the concatenation until it is needed. This new kind of object should understand the same protocol as string. This could all be handled underneath the covers. If it was done at the VM or compiler level, programmers would never have to know.

I thought I would do a sample implementation. It's rather easy (in a dynamic language). First, we need to implement a Promise class and here's the Ruby code complete with a simple test:

require 'rubyunit'

class Promise
  def initialize(&block)
    @calculation=block
    @value=nil
  end
  
  def value
    return @value if @calculation.nil?
    @value=@calculation.call()
    @calculation=nil
    freeze()
    return @value
  end
  
  def value?
    @calculation.nil?
  end
end

def promise(&block)
  Promise.new(&block)
end

class PromiseTest < Test::Unit::TestCase
    def test_simple
      promise = promise { 3 + 4 }
      assert(!promise.value?)
      assert(7 == promise.value)
      assert(promise.value)
    end
end

Pretty simple, huh? Create a new Promise object on a block (or closure or lambda or whatever you like to call it) and it will only call the block once when the message "value" is sent to it. If the message "value" is never sent, the block is never evaluated. Can you think where that might come in handy? I can think of several, but the best one is when trying to create a message to log. If you don't log the message, you wouldn't need to do the concatenation. Again, not doing the computation upfront can not only allow us to manage memory better, but also not to do needless calculations.

Enough talk, let's get to the good stuff, right? Here's my implementation of delaying concatenations and check the tests out at the bottom:

require 'stringio'

class DelayString
  def initialize(oneString, anotherString)
    @strings = [oneString, anotherString]
    @promise = promise do
      stream = @strings.inject(StringIO.new) do |output,each| 
        output << each
      end
      @strings = nil
      freeze()
      stream.rewind
      stream.read
    end
  end
  
  def +(another)
    return another.concatBeforeDelayString(self)
  end
  
  def concatBeforeString(another)
    @strings.unshift(another)
    self
  end
  
  def concatAfterString(another)
    @strings.push(another)
    self
  end
  
  def concatBeforeDelayString(another)
    strings_each do |each|
      another.concatAfterString(each)
    end
    another
  end
  
  def concatAfterDelayString(another)
    another.concatBeforeDelayString(self)
  end
  
  def to_s()
    @promise.value()
  end

  private
  def strings_each(&block)
    @strings.each(&block)
  end
  
end

class String
  def +(another)
    return another.concatBeforeString(self)
  end
  
  def concatBeforeString(another)
    another.concatAfterString(self)
  end
  
  def concatAfterString(another)
    DelayString.new(self, another)
  end
  
  def concatBeforeDelayString(another)
    another.concatAfterString(self)
  end
  
  def concatAfterDelayString(another)
    another.concatBeforeString(self)
  end
end

class DelayStringTest < Test::Unit::TestCase
    def test_simple
      add = "3" + "4"
      assert_equal("34", add.to_s)
    end
    
    def test_string
      add = "3" + "4"
      add = "2" + add
      add = add + "5"
      assert_equal("2345", add.to_s)
    end
    
    def test_delay
      add_before = "1" + "2"
      add_after = "3" + "4"
      add = add_before + add_after
      assert_equal("1234", add.to_s)
      #make sure to get same answer twice 
      assert_equal("1234", add.to_s)
    end
end

One new class called DelayString handles not doing the concatenation until absolutely necessary. It does this by creating a Promise that calculates the string by using a StringIO object (Stream or StringBuilder in Java terms). All it does is keeps a collection of all the strings it needs to append to one another. The power is now that we get the nice succinct message "+" and all of the benefits of using a stream object (or StringBuilder). Of course, we would need to add more methods on our DelayString so that it has the same protocol as String. A little more work to make our implementation seamless.

Below is the test method I added to find the times it took to run for delayed and normal concatenation:

    def test_performance
      add = ''
      1000000.times do |iteration|
        add = add + 'a'
      end
      add.to_s
    end

The new delayed implementation ran at 23.8 seconds. Not bad to do a million additions and a lot of little ones at that. Now, what were the results the old way? Well, all you have to do is comment out the + message:

#  def +(another)
#    return another.concatBeforeString(self)
#  end

It took 4565.68 seconds to run the normal way. It performed poorly and took up a bunch of memory. Yuck. It's what the books warned us about right? It's what we expected somewhat. I didn't expect how much of a performance gain I really got. Pretty cool, huh? Amazing.

It's unlikely that we'll do something to this extreme in the real world. But, wouldn't it be nice to not worry about performance in our regular code? If we find that our implementation is sub-par, one of the new benefits is that we can change it in one place.

Wait a minute. We just got better performance and got to keep the simple way of doing things? Not one lick of our already existing code had to change. The power of messages is powerful indeed!

Quiet Lately

It's been a busy couple of months for me. I've been giving a bunch of talks (Refactoring, Good APIs, and Design). Switched from being a consultant to an employee working for an incredible team. I spent two weeks traveling and to top it off, I saw some of my fave artists (Alice Cooper, Behemoth, and Shadow's Fall) and caught a late summer cold. Still recovering from the cold and trying to get back into blogging. Sorry for being so quiet, I plan to correct that situation soon. Life is getting back to normal. I just got to kick this cold.

My Favorite Smalltalk is Gone

I am so sad. I come back from seeing one of my favorite artists only to read sad news. I can not express how much I enjoyed working in Dolphin and using it. I was a proud supporter and was always excited to see a new version. This really sucks. Dolphin had the best Smalltalk period. In fact, it's the one I used to get people hooked. It looked modern and was extremely easy to use.

I realize it's hard to make money in the software development tools business. My own business failed as well. I was hoping for Dolphin to stick it out. Good luck to the Dolphin guys. I just want to thank them for all the love they put into the world. Dolphin will always have a special place in my heart. It will be hard to say good-bye.

Well, there's no reason for me to stay with Windows anymore now.

Sign Your Real Name

Penelope Trunk recently wrote a blog entry on why you should blog under your real name. I agree completely with all of her points. I would also add to comment under your real name as well. Personally, I can't stand anonymous comments or even ones with nicknames. If you're going to say something, stand beside it. Don't hide. Defend it. Dig?

Bad Code

I have a thing for bad code. In fact, I've been talking every month at the Omaha Java User's Group about it every month by refactoring ugly code. Well, I ran into this article about poor practice in coding examples. Don't worry give it a quick click. It's bewildering no matter how much technology changes, bad code remains. What's even more worrisome is I see the same errors in code today. It makes me wish they gave out Code Complete to everyone.