LOL.

There's is a paper by Kent Pitman, about something about why lisp
doesn't have copy or the complexities of meaning of equality. This
essay is often cited by lispers in comp.lang.lisp, about every few
months in the past 9 years.

the current url is here:
 http://www.nhplace.com/kent/PS/EQUAL.html

I became aware of this essay maybe in early 2000s. I actually never
red it. I just knew that it's something lisper quote frequently like a
gospel. In the back of my mind, i tend to think it is something
particular to lisp, and thus is stupid, because many oft-debated lisp
issues, never happens in Mathematica, nor any dynamic langs i have
become a expert of since 2000. (e.g. perl, python, php, javascript.).

Today, out of boredom, i went and took a look (it has been just cited
again, by a old-time lisper Rob Warnock). I thought: let's see what
would happen, and perhaps it would cause me to write some damning
refutation about it.

This is when i LOL'd.

The paper, basically indicates a fundamental problem of lisp i have
tried to tell lispers for long. Namely: The cons prevents lisp from
developing into a coherent, consistent, libraries of functions that
deals with tree data. Secondly, the problem is caused by Lisp's
“internal” representation of things so-called “object”.

It is not a wonder, why these problems doesn't occur in other dynamic
languages, in particular PHP, Mathematica. (it does occur to some
degree in Perl, since it somewhat heavily relies on some “internal”
gook about references, type globs, file handles, distinction of its
own peculiar notion of list and array, etc.)

These 2 issues i have discussed in depth in the past. See:

• Fundamental Problems of Lisp
  http://xahlee.org/UnixResource_dir/writ/lisp_problems.html

• Is Lisp's Objects Concept Necessary?
  http://xahlee.org/emacs/lisps_objects.html

here's a short quote from the first essay:

«Lisp at core is based on functional programing on lists. This is
comparatively a powerful paradigm. However, for historical reasons,
lisp's list is based on the hardware concept of “cons” cell. From a
mathematical point of view, what this means is that lisp's lists is
limited to a max of 2 elements. If you want a longer list, you must
nest it and interpret it in a special way. (i.e. effectively creating
a mini-protocol of nesting lists, known as proper lists.) The cons
fundamentally crippled the development of list processing.»

Many lispers do not understand it, in fact actively accuse me of no
understanding. (this is in the context of comp.lang.lisp.) Most of
this reaction is rather just being defensive. (i presume lispers in
real life would receive it better.)

Kent's essay, may be viewed with 2 reactions. One of them, typically
taken by lispers, is this:

1. Typical programers are ignorant about lisp. They should learn lisp
before “attacking” (and see the light!).

However, it can be viewed in another way:

2. Lisp is a old lang, one of the first lang, with first running
version in the 1960s. Many later development in computing theory,
isn't caught up in lisp for many social reasons that is naturally
understandable, in particular after 1990s when lisp ceased to be used
in the industry. Many lisp's ways, thus is quaint, incompatible with
today's language views and practices, and sometimes, if not often, not
the best.

  Xah
∑ http://xahlee.org/

How about that?

A number of new lisp langs, tried to fix the cons in various ways.
I think newLisp has index access to list elements instead of car/cdr.

  Xah
∑ http://xahlee.org/

<sigh>

rly, how to you explain the above? Is it really because other langs
don't get it? their design decision is bad? Their design traded off
something very important? They missed linked list by mistake? Or,
perhaps, their views in general of not including linked list (whatever
that means), is just a modern school of thought, which, in old-time
lisper's school of thought, is really bad decision??

really, what the fuck is a linked list? O, this is not a rhetorical
question. Define, explain, what exactly it is? Is it defined by the
syntax of nesting cons?? Or, is it a abstract concept? Is it a
computer language implementation detail on a sequence kinda abstract
entity?? is it a generic abstract computer science data structure that
can be implemented in any lang? Is it a particular language's
datatype??? humm? hum? all of the above? some of the above? other?
which is your view hum? What aspect, definition, concept, detail, are
you presumably using to imply that lispy langs dropping lisp's cons is
stupid?

Now, pick a definition. Then, let's discuss its relation to the cons,
or the why should or should not it be significant in computer
languages, why lisp has it, why ther langs seemingly have or don't
have it, etc.

Woot kenny, Woot! Meet me in Second Life. We can voice chat, n i
introduce you to sexy chicks if you want.

  Xah
∑ http://xahlee.org/

CL-USER(2): (nth 2 '(a b c d))

  [1;2;3]

The following syntax is used both to construct and dissect a singly-linked
immutable list:

  h::t

For example:

  1 :: [2;3]

builds the list [1;2;3] or matches the list [1;2;3].

  {1, 2, 3}

You can just as well do:

  {1, 2.3, "Hello", a + b c^d}

But what on Earth was the designer of Lisp's cons cell thinking?! I can only
assume it was a bit-twiddling maniac trying to squeeze as much out of a few
bits as possible. But why do that for an inherently wasteful data
structure? Anyway, it certainly has no place in a modern HLL.

No, Ocaml doesn't have linked list. Looook:

 {1,{2,{3,{}}}}
 A  B  C

The list A's second element is referenced to the list B, who's second
element is linked to list C. See? Linked!

O, i forgot, that you forgot to define what you mean by linked list.

What lang has linked list by your definition above? Does Perl, Python,
PHP, Java? I tried to think this, but your def is impricise. What's a
“cell”, “linear sequence”? I mean, it has lots meanings in math,
computer science... depending what special context you are talking
about. The term “data structure” itself is quite flexible too. I mean,
don't you agree that you can implement any data structure with turing
machines too? In your fuzzy definition, then the Mathematica “{1,{2,{3,
{}}}}” is a linked list right? From your def: “data structure”, check.
“composed of cells”, check, “refers to each by reference in a linear
sequence”, check.

  Xah
∑ http://xahlee.org/

If one is not using linked lists but still manages to be efficient,
something tells me there is a linked list in there somewhere (thus
addressing your question below "what is a linked list?").

As for your list of moronic languages (de-hominizing somewhat) all I can
say is that I have heard good things about Clojure. The rest I am happy
to dismiss as in anyway constituting objections by superior example to
anything in CL.

peace,kth

ps. I found us a theme song!

http://www.jango.com/music/Gnarls+Barkley?l=0

"I remember when, I remember, I remember when I lost my mind
There was something so pleasant about that place.
Even your emotions had an echo
In so much space

And when you're out there
Without care,
Yeah, I was out of touch
But it wasn't because I didn't know enough
I just knew too much..."

:)k

Therefore, I have no idea why anyone would want a cons cell...

  type 'a list = A | B of 'a * 'a list

Then you have an equivalence:

  OCaml/F#       Mathematica
  A              {}
  B(1, A)        {1, {}}
  B(1, B(2, A))  {1, {2, {}}}

So they both support linked lists.

  type 'a list = A | B of 'a * 'a list

If the type refers to itself (e.g. 'a t) twice then you have a binary tree:

  type 'a t = A | B of 'a t * 'a t

However, there are several pitfalls here. Linked lists can be cyclic, in
which case "linear" is a confusing term. With immutable singly-linked
lists, you often have several lists that share the same tail:

  let a = [2;3]
  let b = 0::a
  let c = 1::a

So "linear" might be a confusing term there as well.

The most hateful, criminal, langs, roughly from most hateful to less,
are: Perl, C, C++, Java.

To a lesser degree, Python, Scheme, Haskell should be attached to the
end above.

You'll note, it's not about the tech nature of the lang.

• What Languages to Hate
  http://xahlee.org/UnixResource_dir/writ/language_to_hate.html

plain text version follows.

----------------------------
What Languages to Hate

Xah Lee, 2002-07-18

Dear lisp comrades and other concerned parties,

First, all languages have equal rights. Do not belittle other
languages just because YOUR favorite language is a bit better in this
aspect or that. Different people have different ideas and manners of
perception. Ideas compete and thrive in all unexpected fashions.
Societies improve, inventions progress. Lisp may be a first in this or
that, or faster or flexibler, or higher level than other languages old
and new, but then there are other languages the like of Mathematica &
Haskell & Dylan et al which ridicule lisps in the same way lisp
ridicule other languages.

Just because YOU are used to more functional programing or love lots
of parenthesis doesn't mean they are the only and best concepts. The
so-called Object Oriented programing of Java fame, or the visual
programing of Visual Basic fame, or the logic programing of Prolog
fame, or the format-stable syntax of Python fame, or the “one line of
Mathematica equals ten to one thousand lines of lisp” of _A New Kind
Of Science_ fame... all are parts of healthy competing concepts,
paradigms, or directions of growth.

The way some of you deride other languages is like sneering
heterogeneousness. If unchecked, soon you'll only have your sister to
marry to. Cute, but you do not want incest to become the only sex.
Next time your superiority complex makes you sneer at non-lisp or
newfangled languages, remember this. It is diversity of ideas, that
drives the welfare of progress.

Now, there is one judgmental criterion, that if a language or computer
technology fits it, then we not only should castigate at their
missionaries, but persecute and harass the language to the harshest
death. That is: utter sloppiness, irresponsibility, and lies. These
things are often borne out of some student's homework or moron's dirty-
work, harbored by “free” and wanton lies and personal fame, amassed
thru ignorance.

Of my short but diligent industrial unix computing experience since
1998, i have identified the following targets:

    * C (and consequences like csh, C++)
    * vi
    * Perl
    * MySQL
    * unix, unixism, and things grown out of unix. (languages,
protocols, philosophies, expectations, movements)

In our software industry, i like to define criminals as those who
cause inordinate harm to society, not necessarily directly. Of the
above things, some of their authors are not such criminals or are
forgivable. While others, are hypocritical fantastic liers selfish to
the core. When dealing with these self-promoting jolly lying humble
humorous priests and their insidious superficially-harmless speeches,
there should be no benefit of doubt. Tell them directly to stop their
vicious lies. Do a face-off.

As to their brain-washed followers for example the not-yet-hard-core
unix, C, or Perl coders rampant in industry, try to snap them out of
it. This you do by loudly snapping fingers in front of their face,
making it sound like a ear piercing bang. Explain to them the utter
stupidity of the things they are using, and the harm to their brain.
IMPORTANT: _teach_, not _debate_ or _discuss_ or falling back into
your philosophical deliberating indecisiveness. I've seen enough
criticisms among learned programers or academicians on these, so i
know you know what i'm talking about. When you see a unixer
brainwashed beyond saving, kick him out of the door. He has became a
zombie who cannot be helped.

There are other languages or technology, by itself technically are
perhaps mediocre but at least is not a egregious irresponsible hack,
therefore does not deserve scorn, but sometimes it comes with
overwhelming popular outrageous lies (euphemized as hype). Java is a
example. For this reason, it is equally deserving the harshest
treatment. Any loud proponents of such should be immediately slapped
in the mouth and kicked in the ass in no ambiguous ways.

Summary: all languages have equal rights. However, those utterly
SLOPPY and IRRESPONSIBLE HACKS with promoter's LIES should be severely
punished. It is these, that cause computing industry inordinate harm.
Meanwhile, it is wrong to haughtily criticize other languages just
because they are not your cup of tea. Now, please remember this and go
do society good.

  Xah
∑ http://xahlee.org/

as to “deep structure”, that often means like a list that uses
reference in its elements to other lists, or create the tech-geeker
loved jargon circular list. This type of thing, is passe of the 1980
or early 1990s with low level languages. In high level langs or
today's langs, basically the concept of “reference”, “pointer” is
gone. Sure, in today's lang sometimes you could have still see it uses
the “a reference” terminology pecular to itself but has the general
meaning of “reference” in the contex of compiler. (e.g. OCaml has
“ref”) But basically, the entity of something that is intimately tied
to compiler stuff or “internal” stuff is gone, and programers don't
have to worry about that. (similiar applies to memory stuff. Tech
geeking morons daily sway & swoon about “garbage collection”. Garbage
collection, Garbage Collection. The ins and outs of garbage
collection. The speed of garabage collection. The types of garbage
collection.)

If you want a reference, you can implement in any high level lang that
has sufficient functional programing features such as control of eval,
first class function. Basically, you just use a variable for the
“reference”, with eval or holdEval.

--------------------------

Kenny, have you tried Second Life? Really... it's fun. There's lisp
group in world... but more so it's really a lot things, concepts,
practical utilities to explore.

For those unfamiliar:

• A Photographic Tour of Life in Second Life
  http://xahlee.org/sl/index.html

• Second Life, Tech Geekers, And Escapism
  http://xahlee.org/Netiquette_dir/Second_Life_vs_newsgroup_escapism.html

As to Second Life, I am not looking for more ways to get fat sitting at
a computer, I am looking for another tennis partner.

As for "Crazy" by Gnarls Barkley, there was a play button on that page
you need to find it because it is an amazing tune, won some awards that
year.