How To Estimate Software

A guide to estimating percentage complete and remaining time.

I haven't looked at the problem. Completed: 0% Time esimate: about 2 weeks.

I've looked at the problem. Completed: 50% Time estimate: about 2 more weeks.

I've implemented almost everything. All that remains is the difficult stuff that I don't really know how to do. Completed: 90% Time estimate: about 2 more weeks.

I've done everything. All that remains is documentation, code review, tests and error handling. Completed: 99% Time estimate: about 2 more weeks.

I still haven't finished documentation, code review, tests, or error handling. The truth is I've been gold plating what I already wrote. But I just saw another problem that seems more interesting. Completed: 100% Time estimate: 0 more weeks.

Sometime in 1977

Kernighan:

"I know, let's open the book with a program that displays 'hello, world.'"

Ritchie:

"Great idea! I'll start the patent search."

Who Will Throw the Hammer This Time?

During the 1984 Super Bowl, Apple released an ad where gray, drab people are transfixed on a giant screen with a talking head who tells them how utopian their uniform world is. A female athlete jogs in and throws a hammer at the screen, the screen explodes, and a new voice announces the release of the Apple Macintosh.

The ad riffed off of the George Orwell dystopian novell Nineteen Eighty-Four. Orwell's 1984 features a powerful central state that controls society absolutely. One of its mechanisms for control lies in saying one thing while meaning the opposite. The Ministry of Peace is in charge of war, the Ministry of Truth is in charge of the falsification and censorship, etc.

In an exchange with Gawker's Ryan Tate, Steve Jobs attempts some verbal judo but comes out with some near doublespeak of his own. Tate says "Revolutions are about freedom" and Jobs replies "Yep...Freedom from porn."

Look, I'm not advocating for porn. It seems to be doing just fine without me. But I am irritated by Jobs deliberately muddling "freedom" as in "in a democracy you have the freedom to vote" with the opposite "in a dictatorship you have freedom from worrying who to vote for." Combined with licensing that squashes Flash, Scratch and RunRev and the Apple world starts looking gray and drab. Meanwhile, Jobs explains that all this "freedom from" stuff is really what we want in his magic little utopia.

So we come full circle and I ask who will throw the hammer this time?

Post Script

BoingBoing has a video with a premise similar to my picture.

Robert Fischer Finally Admits that Scala is Functional

Robert Fischer says

If your language doesn’t lead people to re-discover point free programming at least in the small, then the language really isn’t taking function manipulation and functional language type conceptions seriously.

Thus Fischer has finally recognized that Scala is functional.

val double : Int => Int = 2 * // point free function definition
List(1,2,3) map double /* removes one point from List(1,2,3) map {x 
   => double(x)} */

Thank you Robert for finally getting to the truth.

Oh, the Underscore

Now, Robert may object because I didn't combine map and double into one super function, mapDouble. Okay

val mapDouble : List[Int] => List[Int] = _ map double
mapDouble(List(1,2,3))

Crap, there's an underscore. Is it a "point"? Good question. And the answer is no. In fact, what it is is a hole in the expression. Oleg Kiselyov, somebody who actually knows about functional programming, says they're related to delimited continuations and what could be more functional than delimited continuations?

Also, Erlang Remains Unfunctional

For some reason Fischer really hates on Erlang. Point-free is definitely not Erlang's strong suit at all due to it's ability to overload on arity. I don't know why the Erlangers don't go picket his blog.

Post Script on Converses

David MacIver points out (correctly) that my post assumes that a statement implies its converse. To that I say "pffft, write your own damn parody, David!"

A Brief, Incomplete, and Mostly Wrong History of Programming Languages

1801 - Joseph Marie Jacquard uses punch cards to instruct a loom to weave "hello, world" into a tapestry. Redditers of the time are not impressed due to the lack of tail call recursion, concurrency, or proper capitalization.

1842 - Ada Lovelace writes the first program. She is hampered in her efforts by the minor inconvenience that she doesn't have any actual computers to run her code. Enterprise architects will later relearn her techniques in order to program in UML.

1936 - Alan Turing invents every programming language that will ever be but is shanghaied by British Intelligence to be 007 before he can patent them.

1936 - Alonzo Church also invents every language that will ever be but does it better. His lambda calculus is ignored because it is insufficiently C-like. This criticism occurs in spite of the fact that C has not yet been invented.

1940s - Various "computers" are "programmed" using direct wiring and switches. Engineers do this in order to avoid the tabs vs spaces debate.

1957 - John Backus and IBM create FORTRAN. There's nothing funny about IBM or FORTRAN. It is a syntax error to write FORTRAN while not wearing a blue tie.

1958 - John McCarthy and Paul Graham invent LISP. Due to high costs caused by a post-war depletion of the strategic parentheses reserve LISP never becomes popular[1]. In spite of its lack of popularity, LISP (now "Lisp" or sometimes "Arc") remains an influential language in "key algorithmic techniques such as recursion and condescension"[2].

1959 - After losing a bet with L. Ron Hubbard, Grace Hopper and several other sadists invent the Capitalization Of Boilerplate Oriented Language (COBOL) . Years later, in a misguided and sexist retaliation against Adm. Hopper's COBOL work, Ruby conferences frequently feature misogynistic material.

1964 - John Kemeny and Thomas Kurtz create BASIC, an unstructured programming language for non-computer scientists.

1965 - Kemeny and Kurtz go to 1964.

1970 - Guy Steele and Gerald Sussman create Scheme. Their work leads to a series of "Lambda the Ultimate" papers culminating in "Lambda the Ultimate Kitchen Utensil." This paper becomes the basis for a long running, but ultimately unsuccessful run of late night infomercials. Lambdas are relegated to relative obscurity until Java makes them popular by not having them.

1970 - Niklaus Wirth creates Pascal, a procedural language. Critics immediately denounce Pascal because it uses "x := x + y" syntax instead of the more familiar C-like "x = x + y". This criticism happens in spite of the fact that C has not yet been invented.

1972 - Dennis Ritchie invents a powerful gun that shoots both forward and backward simultaneously. Not satisfied with the number of deaths and permanent maimings from that invention he invents C and Unix.

1972 - Alain Colmerauer designs the logic language Prolog. His goal is to create a language with the intelligence of a two year old. He proves he has reached his goal by showing a Prolog session that says "No." to every query.

1973 - Robin Milner creates ML, a language based on the M&M type theory. ML begets SML which has a formally specified semantics. When asked for a formal semantics of the formal semantics Milner's head explodes. Other well known languages in the ML family include OCaml, F#, and Visual Basic.

1980 - Alan Kay creates Smalltalk and invents the term "object oriented." When asked what that means he replies, "Smalltalk programs are just objects." When asked what objects are made of he replies, "objects." When asked again he says "look, it's all objects all the way down. Until you reach turtles."

1983 - In honor of Ada Lovelace's ability to create programs that never ran, Jean Ichbiah and the US Department of Defense create the Ada programming language. In spite of the lack of evidence that any significant Ada program is ever completed historians believe Ada to be a successful public works project that keeps several thousand roving defense contractors out of gangs.

1983 - Bjarne Stroustrup bolts everything he's ever heard of onto C to create C++. The resulting language is so complex that programs must be sent to the future to be compiled by the Skynet artificial intelligence. Build times suffer. Skynet's motives for performing the service remain unclear but spokespeople from the future say "there is nothing to be concerned about, baby," in an Austrian accented monotones. There is some speculation that Skynet is nothing more than a pretentious buffer overrun.

1986 - Brad Cox and Tom Love create Objective-C, announcing "this language has all the memory safety of C combined with all the blazing speed of Smalltalk." Modern historians suspect the two were dyslexic.

1987 - Larry Wall falls asleep and hits Larry Wall's forehead on the keyboard. Upon waking Larry Wall decides that the string of characters on Larry Wall's monitor isn't random but an example program in a programming language that God wants His prophet, Larry Wall, to design. Perl is born.

1990 - A committee formed by Simon Peyton-Jones, Paul Hudak, Philip Wadler, Ashton Kutcher, and People for the Ethical Treatment of Animals creates Haskell, a pure, non-strict, functional language. Haskell gets some resistance due to the complexity of using monads to control side effects. Wadler tries to appease critics by explaining that "a monad is a monoid in the category of endofunctors, what's the problem?"

1991 - Dutch programmer Guido van Rossum travels to Argentina for a mysterious operation. He returns with a large cranial scar, invents Python, is declared Dictator for Life by legions of followers, and announces to the world that "There Is Only One Way to Do It." Poland becomes nervous.

1995 - At a neighborhood Italian restaurant Rasmus Lerdorf realizes that his plate of spaghetti is an excellent model for understanding the World Wide Web and that web applications should mimic their medium. On the back of his napkin he designs Programmable Hyperlinked Pasta (PHP). PHP documentation remains on that napkin to this day.

1995 - Yukihiro "Mad Matz" Matsumoto creates Ruby to avert some vaguely unspecified apocalypse that will leave Australia a desert run by mohawked warriors and Tina Turner. The language is later renamed Ruby on Rails by its real inventor, David Heinemeier Hansson. [The bit about Matsumoto inventing a language called Ruby never happened and better be removed in the next revision of this article - DHH].

1995 - Brendan Eich reads up on every mistake ever made in designing a programming language, invents a few more, and creates LiveScript. Later, in an effort to cash in on the popularity of Java the language is renamed JavaScript. Later still, in an effort to cash in on the popularity of skin diseases the language is renamed ECMAScript.

1996 - James Gosling invents Java. Java is a relatively verbose, garbage collected, class based, statically typed, single dispatch, object oriented language with single implementation inheritance and multiple interface inheritance. Sun loudly heralds Java's novelty.

2001 - Anders Hejlsberg invents C#. C# is a relatively verbose, garbage collected, class based, statically typed, single dispatch, object oriented language with single implementation inheritance and multiple interface inheritance. Microsoft loudly heralds C#'s novelty.

2003 - A drunken Martin Odersky sees a Reese's Peanut Butter Cup ad featuring somebody's peanut butter getting on somebody else's chocolate and has an idea. He creates Scala, a language that unifies constructs from both object oriented and functional languages. This pisses off both groups and each promptly declares jihad.

Footnotes

1. Fortunately for computer science the supply of curly braces and angle brackets remains high.
2. Catch as catch can - Verity Stob

Edits

• 5/8/09 added BASIC, 1964
• 5/8/09 Moved curly brace and angle bracket comment to footnotes
• 5/8/09 corrected several punctuation and typographical errors
• 5/8/09 removed bit about Odersky in hiding
• 5/8/09 added Objective-C, 1986
• 5/8/09 added Church and Turing
• 4/9/10 added Ada (1983) and PHP(1995)

Java Is Too Academic

Occasionally you'll hear people praising Java because it's incredibly readable; there's only one way to do things; and other languages are too academic. But I have proof that they're wrong. After you view the code below I think you'll agree with me that with Java:

1. It's far too easy to write code that's illegible to most programmers.
2. There are far too many ways to do things.
3. It's far too academic.

I have reason to believe other popular languages like Ruby and Python allow this sort of thing, too. When will we finally stop inventing such academic languages and let real world working programmers get some real world work done?

The proof that Java is too academic and obscure? Right here: factorial using a fixed point operation in an applicative order lambda calculus. "Obscure" and "academic" don't even begin to describe this code*.

public interface Lambda {
    public Object apply(Object x);
}

public class Factorial {
 public static void main(String[] args) {
  final int x = new Integer(args[0]);
  
  System.out.println(x + "! = " + 
  ((Lambda)(new Lambda() {
   public Object apply(final Object f) {
    return new Lambda() {
     public Object apply(final Object x) {
      return ((Lambda)f).apply(new Lambda(){
       public Object apply(final Object y) {
        return ((Lambda)((Lambda)x).apply(x)).apply(y);
       }       
      });
     }     
    }.apply(new Lambda() {
     public Object apply(final Object x) {
      return ((Lambda)f).apply(new Lambda(){
       public Object apply(final Object y) {
        return ((Lambda)((Lambda)x).apply(x)).apply(y);
       }       
      });
     }     
    });    
   }   
  }.apply(new Lambda(){
   public Object apply(final Object f) {
    return new Lambda() {
     public Object apply(final Object x1) {
      final int x = (Integer)x1;
      return x == 0 ? 1 : x * (Integer)((Lambda)f).apply(x -1);      
     }
    };
   }   
  }))).apply(x));
 }
}

* "Obscure" and "academic" may not begin to describe it, but "perverse" starts getting close

Of Reading, Posting Comments, and Debates

I can't for the life of me figure out how to get a comment to post on Ted Neward's blog article critiquing the discussion in my previous post. Perhaps my comment is being moderated, but the system didn't say so.

So I'll put it here.

[Edit: whatever was wrong seems to be fixed now. I was able to post a comment, but the original seems to have been eaten. That's okay, it's more complete here.]

In Neward's article he takes everybody to task. And he raises some valid points, which I'll get to at the end, but first there are some factual errors.

---

Neward:> Citing yourself as the final authority. At no point during the debate does anybody reach for their copy of Effective Java

Well, not Effective Java, but there's plenty of arguing from authority with quotes and everything. The authority in this case is Sun's Javadoc for the Java standard library.

(10:05:37 AM) JamesIry: From the doc: The equals method for class Object implements the most discriminating possible equivalence relation on objects; that is, for any non-null reference values x and y, this method returns true if and only if x and y refer to the same object (x == y has the value
...
(10:08:44 AM) JamesIry: Also from the doc: As much as is reasonably practical, the hashCode method defined by class Object does return distinct integers for distinct objects. (This is typically implemented by converting the internal address of the object into an integer, but this implementation technique is not required by the JavaTM programming language.)
...
(10:14:26 AM) dysinger: "If two objects are equal according to the equals(Object) method, then calling the hashCode method on each of the two objects must produce the same integer result. "

---

Neward:> nobody even considers the possibility that different JVMs can have different implementations

(09:37:58 AM) ijuma: hashCode is not necessarily good enough because it's an int and you may be running a 64-bit machine
(09:38:23 AM) ijuma: I mean System.identityHashCode above
...
(09:46:50 AM) JamesIry: Read the spec for identityHashCode
(09:47:18 AM) JamesIry: It says not one word about uniqueness guarantees. A perfectly legal JVM could return 0 everytime the method is called.
...
(09:58:10 AM) JamesIry: The fact that a particular jvm uses an object's unique handle as a hashCode is an implementation detail
...
(10:09:10 AM) JamesIry: Note the caveat: this implementation technique is not required by the JavaTM programming language.

---

Neward:> At no point, near as I can tell, did any of the participants bother to say, "You know, you could be right, but I remain unconvinced. Can you give me more information to support your point of view?"

(10:04:19 AM) JamesIry: dysinger please point me to the line in the JLS that says that "==" uses class and hashCode. There's no need for us to argue. Just point it out to me
...
(10:13:43 AM) dysinger: show me the code

---

Neward:> Nobody ever really gets around to answering the question because they're too busy arguing their position or point. Poor "doub",

(09:57:24 AM) doub: but I agree with all you said JamesIry, and I would use .eq for a production system

---

Neward:> Here's a tip for all of you: Try listening

And right back at you, Ted.

---

Where was he right? Well, right here:

Neward:> The interesting thing, though, is that this conversation has nothing to do with Scala.

Exactly. In fact, with only a bit of renaming it could have been held in #java. With only little bit more extra work most of it could have been about any language that supports distinct concepts of identity and semantic equality - which is a heck of a lot of them. It also impinges on the concept of hashing, which is a fairly universal CS tool - and even on a concept I learned as The Pigeon Hole Principle.

---

Neward:> And frankly, I find the dig at the academics to be a tad disingenuous.[...]Way to bite the hand that makes your life easier, [Tim Dysinger]....

Very well said, Mr. Neward, very well said. Except the part I edited which actually said

Neward:> Way to bite the hand that makes your life easier, folks....

I'm not sure who else took a shot at academics there, but whoever you are, I'm on Ted's side!