developer.* Blogs - blog entry - Comments

Thanks

chrishmorris — Tue, 15 Jan 2008 23:59:33 -0800

We have a weekly phone conference for the project team. At the end of a week's testing, one team member thanked another for finding defects in his code. A great moment.

On foolishly defending another person's reputation

Edward G Nilges — Wed, 09 Jan 2008 22:00:03 -0800

Part of the reason for the vicious attacks I was subjected to on the Lamma Island placeblog www.lamma.com.HK was the fact that I defended a poster with gender ambiguity. This apparently caused the stalkerette, who'd introduced herself to me in September, to betray me thereafter, turning against me on the placeblog.

She was careful to assure me that the gender-ambiguous poster was in some way a troll, where we get to deny the reality of trolling by conflating a definition based on an image of a marginal character without a life, and the original definition, which had to do with posting insincerely to get a response.

However, as I pointed out to the stalkerette at the time, it's rather hard to express gender-ambiguity insincerely, if only because the expression is the ambiguity. If some regular guy gets drunk and makes a half-ironic homosexual pass at another regular guy, he ain't kidding.

His enemies were using irony absolutely and not ironically. It was very important for them to maintain the pose of the ironic funny guy in the pub who knows anything worth knowing, and at any time (such as the time I posted Yeat's poem Sailing to Byzantium, its line "this is no country for old men" being my comment on Lamma Island) that pose is challenged, the challenge like Carthage must be ironically dismissed as somehow, in some way, not with it.

The group pursued him as Schildt was pursued, focusing not on the outside world but on his inadequacy with a childish obsessiveness that I also saw in the hounding of Schildt.

The rather wise for her years gallery owner here assured me "people aren't interested in art". No, they aren't, and I do observe amongst the better heeled in Hong Kong and amongst wealthy expats, a complete failure to take interest in much of anything except personalities and individual wealth...when any one of them finds the personalities with which they have been affiliated unkewl, they abandon them, or, in a celebrated case a couple of years ago (Nancy Kissell) they feed 'em a poisoned milk-shake, and, when this doesn't work, they bludgeon their sweeties to death.

Code mostly bores and angers the people who infest comp.programming to the extent that the only thing that galvanizes people are finding mistakes, not usually hard bugs, but questions of style...just as "what main() returns", and not the desparately important issue of "what can be asserted at time t" becomes a central fashion statement amongst latter-day C and C++ programmers...to the extent that even Bjarne Stroustrup falls prey to this *weltanschaung* and *zeitgeist*, and tells the reader in his C++ faqs that "you must know this not to seem stupid"...not because it is TRUE.

This is why I got Schildt's article cleaned up. I've seen whole companies destroyed by "people persons" who use a sort of decayed New Age rhetoric to do their jobs by classifying their co-workers into acceptable types and weirdos.

Schildt article cleaned up in response to my statement

Edward G Nilges — Wed, 09 Jan 2008 21:43:06 -0800

The Schildt article has been cleaned up by a non-anonymous editor in response to my statement and is now a fair statement of this person's record.

If you see a Wikipedia article created in order to attack, or vandalized with personal attacks, don't allow this "free speech". Exercise your freedom of speech, because (as I tried to make clear in my usenet post "Brian Kernighan, Maybe I'm Not Worthy, Maybe I'm Scum" you can criticise the output or affects of a person without focusing on the person with statements such as "don't trust Schildt", statements that globally trash a person.

Change the article to remove language of the form "x is y" where x is a person's name, and y is a general predicate unsupportable by the evidence, such as "incompetent".

In Schildt's case, he'd done well in 1989 by writing a recursive descent parser and interpreter for a subset of C in somewhat the same way my book does this for Quick Basic, and followed up in the early Nineties with a great book on C, "Born to Code".

He came a bit of a cropper in 1999 with The Complete C++ Reference because he ignored the power of the "standardisation" movement which is foolishly trying to standardize a language which is intentionally non-deterministic and machine-dependent.

However, this was no reason to launch a global, and Stalinist, campaign against Schildt as a person. The problem is that many people in technology are, in their ignorance of history and Stalinism, unconsciously Stalinist.

Like the followers of Stalin they prefer talking about personalities to thinking hard about engineering. For example, it is impossible for them to reflect that the standard is silent on the representation of negative numbers while out there in the real world, most of the time, negative numbers are represented twos-complement, and that a mentor like Schildt is bound to pass on this fact.

The attacks on Schildt have been checked on wikipedia. Don't let people use "freedom of speech" to so globally dismiss, not a thesis, but a person.

Pike and Kernighan: .6 secs: C Sharp: 2.7

Edward G Nilges — Wed, 02 Jan 2008 22:46:26 -0800

...for a long string, AFTER one million iterations.

See main blog post.

A note on "conforming strings"

Edward G Nilges — Sun, 30 Dec 2007 06:28:36 -0800

In wanting to return the start index and the length of the string that conforms I return counterintuitive results such as an index of 0 and a length of 1 for the regex CC* and the string CC, and, even worse, an index of 0 AND A LENGTH OF 0 for the regex C* and the string CC, using Pike's code, because Pike's code gets shortest string.

Independent of programmer implementation, there is a mathematics of regular expressions (that is not necessarily the property of professional mathematicians, any more than a regex processor defines human reality).

A programmer would observe that there isn't one and only one conforming substring, and that the conformant string is defined by the User, assuming you can find one (the "user" is an undefinable buzz word). A mathematician would say that the conformant strings are a plurality which can be thought of as a SET.

Therefore, any real regular expression processor has to by default give the caller the start index and length of the longest conformant string, NOT the shorter: Pike's code is mislabeled.

The longest conformant string can stand for the set since the set of conforming strings is just the set of substrings starting at the index i of the longest string, and then substring (i+1, maxlength-1), (i+2, maxlength-2) .. (i + maxlength - 1, 1). If the regex ends in an asterisk then the set also includes the null string.

This model can be extended to carat and dollar (the characters representing start and end of string) by transforming the input string s to ^s$ in a meta-notation.

Which means that a solid regex would return an object, a class, that allows retrieval of each conformant string from a set model. This class could implement laziness in a sweet fashion: if asked for the first and shortest conformant string, it could get only the conformants just-in-time by using an algorithm where the maximum length of conformant string, relative to the minimum, would be a parameter!

Indeed, a solid regex would be a class with methods that would EXPLAIN regular expressions, producing outputs such as "gets at least one C" for CC*, allowing its use as a real tool as opposed to a rather misleading snippet.

The ability to think in sets as opposed to bytes doesn't seem to transfer across the boundaries between languages, between languages that explicitly handle sets, and languages like C. In Beautiful Code, I don't see the beauty of ontology...making objects that correspond to thought.

((((poot)))*)

Edward G Nilges — Sun, 30 Dec 2007 04:53:46 -0800

I also failed to realize that the test variable in Pike's "Beautiful" code isn't at all updated in matchhere() or matchstar() on behalf of match(): as in match() itself, the copy of test on the stack is used as a working variable. Basically, no effort at all was made by the Pikester to return the position of the satisfying string, and in the so-called real world, isn't this exactly your next question?

(((poot)))

Edward G Nilges — Fri, 28 Dec 2007 04:15:24 -0800

Sorry, hopefully only one more error: I imply that you DO get the address IF you pass the test string in a variable. This is incorrect since value parameters in C are copied to the stack and, if modified, that modification is lost.

Which means that the original objection stands. The code isn't at all useful for finding WHERE the string, that satisfies the regular expression, exists in test. It merely finds WHETHER it occurs.

Is such spare functionality Beautiful? I don't know. It sure isn't Reusable.

Nonsense prevails, modesty fails
Grace and virtue turn into stupidity
While the calendar fades almost all barricades to a pale compromise
And our leaders have feasts on the backsides of beasts
They still think they're the gods of antiquity
If something you missed didn't even exist
It was just an ideal -- is it such a surprise?

What shall we do, what shall we do with all this useless beauty?
All this useless beauty

kscaldef's comment on the Kernighan code in reddit

Edward G Nilges — Thu, 27 Dec 2007 10:47:04 -0800

kscaldef points out, with respect to my point (1), that you don't need in a minimal implementation to support a+ where + means one or more times: you just use aa*!

But I add at reddit that the code doesn't support nesting in the regular expression as in (a+c)*.

It's syntactic sugar to insist that Rob should have supported postfixable strings as well as characters (although the failure to support international characters is significant). But by allowing parentheses Rob could have had strings for free as in (abc)*.

I'm on admittedly shaky ground. A pure mathematician would ACCEPT only character processing, equating the char with a symbol on a Turing Machine square, and assume that any string could be represented as any one of an infinity of possible characters, as Chinese ideograms represent thousands of ideas.

A programmer like Rob simply restricts himself to the problem statement, so Rob did good.

What remains for me unforgiveable is that this hack is considered Beautiful Code by Brian, at least without a considerable discussion of its limitations. I'd accept it as neo-Primitive art if only Brian had done so.

Recursive brain fart ((poot)*)

Edward G Nilges — Thu, 27 Dec 2007 08:21:19 -0800

Of course, most users of the Pike code will pass a string literal as the "test" parameter, thereby losing the address of the satisfier.

(poot)*

Summary of the flaws I think are in the Kernighan and Pike code

Edward G Nilges — Thu, 27 Dec 2007 08:19:27 -0800

A discussion of the above blog post has started on programming.reddit.com in the usual way, with complaints about literary style rather than technical remarks, because, as one poster says, pointer arithmetic is hard.

Because the reddit posters complained about the political observations, I posted the following technical discussion at http://programming.reddit.com/info/63vc1/comments/.

Here is a summary of what I think are the flaws in the code Rob Pike wrote for Brian Kernighan, and which Brian presents as Beautful Code in a book of that name, published this year by O'Reilly, on page 3 (an unindented copy of Rob's code as keyed by me, and wrapped in a C++ class, is at my developerDotStar blog). I read C but have long since abandoned it because I don't think Beautiful Code can be written in C: the Pike code, I think, is an example of code that only seems Beautiful.

I won't include any postmodern theory in this particular post despite the fact that aesthetics is political.

(1) Pike's code doesn't implement a regular expression interpreter insofar as "regular expressions" have a formal, mathematical meaning. For example, it makes no provision for a character which must occur at least once.

(2) It is idiomatic C, which uses a parameter passed by value as the changeable index into the string it points-at and it expects the user to grok the fact that she has a useful value in that value parameter (the start of the text conforming to the regular expression), something unexpected outside of C. If the user passes the text as a string literal, the useful point at which the regular expression occurs is lost.

(3) While advertised as a string processor, it does not handle modern Unicode or double-byte strings containing international input.

(4) Its comments are unilluminating especially as regards need-to-know the fact that its value parameter contains a useful result (the start position of the regular expression), and Brian's discussion in Beautiful Code is unhelpful. Of course, as noted above, this address is lost when a string literal is passed.

(5) The length of the substring of characters that satisfies the regular expression is lost.

(6) Kernighan does express, in the text of the essay, the concern that the code, which does heavy recursion proportional to the string length, might run slowly or overrun stack limits.

But no consideration exists in the code that a semi-beautiful way exists to avoid most recursion. If the regular expression does not start with a string start carat or string end dollar sign, its first character, if not followed by an asterisk, is a "handle" which which can be scanned-for in a nonrecursive loop or by a strcspn function.

Even if the first character (that's not dollar or carat) is followed by an asterisk, if the asterisked character occurs frequently, the code can search for the first character, and return a match immediately upon finding it, or, entering the recursive code upon failure.

What would be Beautiful about this? The fact that it's not the sort of thing an optimizing compiler would "think" of, whereas the apparent efficiency of Pike's code is often discovered by an optimizing compiler (although an optimizing compiler would not "see" the utility of recursion in an iterative solution, to be sure).

It would, I think, amortize the cost of using a platform, whether Java or C Sharp, that handles real strings through an abstraction.

Please feel free to point out where I've gone off the rails, since I have such respect for Kernighan that I'm astonished that he feels that this snippet is Beautiful Code.

Tom Paine

Edward G Nilges — Thu, 27 Dec 2007 00:29:33 -0800

As I went out one morning
To breathe the air around Tom Paine's,
I spied the fairest damsel
That ever did walk in chains.

I offer'd her my hand,
She took me by the arm.
I knew that very instant,
She meant to do me harm.

"Depart from me this moment,"
I told her with my voice.
Said she, "But I don't wish to,"
Said I, "But you have no choice."

"I beg you, sir," she pleaded
From the corners of her mouth,
"I will secretly accept you
And together we'll fly south."

Just then Tom Paine, himself,
Came running from across the field,
Shouting at this lovely girl
And commanding her to yield.

And as she was letting go her grip,
Up Tom Paine did run,
"I'm sorry, sir," he said to me,
"I'm sorry for what she's done."

Brain Fart

Edward G Nilges — Wed, 26 Dec 2007 23:50:42 -0800

It wasn't until I posted to comp.programming that in an exchange with Malcolm McLean that I realized that you DO know where the string occurs when you use the Rob Pike code.

Because the "test" variable is used as an index-address, it contains the start of the regular expression's occurence on exit from a successful search or a null length "string", in the case of failure.

Is this "elegant"? No, since you're not given the length of the string that satisfies the regular expression, and this cannot be determined from very simple regular expressions such as C*!

Furthermore, although it was sorta dumb of me not to see that the test value is a result as well as input, and to recall to mind that C "value" parameters can contain results, Brian should have spelled this out.

No, Brian, I'm not saying "Don't Make Me Think!" I am saying I would have spelled this out and not assumed a knowledge of C, because shibboleths (using idioms to select an audience) are tribal.

Primitive art linked to magic and ritual is beautiful, but it isn't beautiful to in effect celebrate 1971 as a computing year in which the theory of parameter types was in its infancy.

It is said that elegance is in the mind of the beholder, and a reputable literary theory, reader-response, affirms that in part literary elegance depends on an audience.

But this means that the very word, "elegance", has to be subscripted with the name of the audience.

The C expert no doubt gets a *frisson* of delight when he sees, a lot faster than I, that (1) test is used as a work area and (2) test gives back the starting address of the satisfier string.

However, what's missing is an acknowledgement that there's an audience out there of intelligent professional programmers who don't use C, or who used to, but then got help. What's missing is a true computing cosmopolitanism, that of the Algol publication language, that was short-changed by IBM's development of Fortran, and the Eisenhower administration's post-Marshall Plan desire to let the Western Europeans know that they were junior partners.

More cyberstalking and cyberbullying

Edward G Nilges — Mon, 24 Dec 2007 22:31:34 -0800

Kathy made herself a feminist heroine because it's almost impossible for people to imagine themselves as a pure victim.

Identity politics is indeed a protest against ill-treatment, but logically, it's based on an assumption: that the bullying is unfair because one is "really" a member of a group which has been collectively, historically put down.

One becomes a type token rather than a pure "token" (using that word to mean a unique individual not characterisable as a member of a group, say in reality a person with a multi-ethnic background whose identity is generalized).

In identity politics, the logical next step becomes re-identification with Power, in that one says that the bullying is misplaced, BECAUSE one is actually a member of a colonized or oppressed group which once was Master, was then Slave, and shall be Master again.

What you get is Nation of Islam, Chief Buthulezi's Zulu nationalism in South Africa, or Hinduvata politics. And in some of these cases, the newly empowered former victims start victimising in turn, their prototype and role model being, whether they will or no, Israel.

The trick is to stay on the level of Victim identification and compassion.

Nobody likes a "real" victim. He's the Roma in the train station who makes our spic and span Austrian town less spic, and span. He's the queer who's bleeding and might have AIDs. He's the wounded ex-hippie, now homeless, who rages on usenet at the San Francisco public library against hurts fancied based on hurts that are real.

She's the ABC (American Born Chinese) who can't get an English teacher's job in Hong Kong because unlike me she doesn't look like an English teacher.

She's the compiler developer whose PhD thesis was an optimizing Haskell compiler who can't get a compiler development job, developing Yet Another Fortran compiler.

He's the former Master of the Universe of the 1980s who's fallen shall we say on hard times.

The cyberbully is he who sets his face against the wound in himself and stalks another who has that wound in plain sight.

Come from the shadows.

More on cyberbullying

Edward G Nilges — Sat, 15 Dec 2007 08:06:41 -0800

In the case of Megan Meier, a teenager who hanged herself because of MySpace harassment (http://www.nytimes.com/2007/12/16/fashion/16meangirls.html?_r=1&oref=slo...), the mother of one of the bullies helped that bully design a Web page which they pretended was a boy who liked Megan, and exploted Megan's vulnerability without pity.

Cyberbullying isn't a male on female issue, nor is it restricted to kids. The people here on Lamma Island (you know who you are) who harassed me through stalking on the ferry and a destructive campaign organized by two moderators on www.lamma.com.HK are at least chronological adults. The clowns on comp.programming who sent nasty letters to Apress while I was writing Build Your Own .Net Language and Compiler wrer at least chronological adults.

The problem is as I've said that bullying supports and enables societal structures of domination and control.

Everybody must know his proper place in the scheme of things for the system to continue to work to the advantage of the wealthy and powerful, yet, there's a paradox. Domination is work in excess of producing value, therefore we have to dominate ourselves, and, through capillary micropower such as bullying, ensure that everybody else has internalized just enough surplus repression, self-hatred, and the consequent inability to love for people to sacrifice their lives to jobs and mortgages so that the rich get richer.

C. S. Lewis saw long ago how British school bullies formed what he called "The Inner Ring" in an essay of that name and how it exerted the will of the masters to have to be bothered, most of the time, with the least difficult, most extroverted, and most tractable boys, while making sure that the creativity (of a "Piggy" in Lord of the Flies) or the rebelliousness of a Long Distance Runner who wins the race but refuses to cross the finish line on behalf of his borstal school, don't disrupt existing macro structures of power.

Feminists think they can blithely ignore male on male bullying and say "boys will be boys". This ahistorically ignores the fact that most progressive political movements start with outrage against micro-bullying of males by males, and the hegemony of the feminist diversion has renarrated outrage against many forms of bullying as special pleading...as "feminists" such as Hilary Clinton seek merely to inherit the levers of power.

"Your observations are offside", or let us now praise famous men

Edward G Nilges — Mon, 10 Dec 2007 21:43:59 -0800

See my own blog for a comment offside to these discussions.