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How Lisp's Nested Notation Limits The Language's Utility
How Lisp's Nested Notation Limits The Language's Utility
Xah Lee, 2007-05-03
There is a common complain by programers about lisp's notation, of
nested parenthesis, being unnatural or difficult to read. Long time
lisp programers, often counter, that it is a matter of conditioning,
and or blaming the use of inferior text editors that are not
designed to display nested notations. In the following, i describe how
lisp notation is actually a problem, in several levels.
(1) Some 99% of programers are not used to the nested parenthesis
syntax. This is a practical problem. On this aspect along, lisp's
syntax can be considered a problem.
(2) Arguably, the pure nested syntax is not natural for human to read.
Long time lispers may disagree on this point.
(3) Most importantly, a pure nested syntax discourages frequent or
advanced use of function sequencing or compositions. This aspect is
the most devastating.
The first issue, that most programers are not comfortable with nested
notation, is well known. It is not a technical issue. Whether it is
considered a problem of the lisp language is a matter of philosophical
disposition.
The second issue, about nested parenthesis not being natural for human
to read, may be debatable. I do think, that deep nesting is a problem
to the programer. Here's a example of 2 blocks of code that are
syntactically equivalent in the Mathematica language:
vectorAngle[{a1_, a2_}] := Module[{x, y},
{x, y} = {a1, a2}/Sqrt[a1^2 + a2^2] // N;
If[x == 0, If[Sign@y === 1, p/2, -p/2],
If[y == 0, If[Sign@x === 1, 0, p],
If[Sign@y === 1, ArcCos@x, 2 p - ArcCos@x]
]
]
]
SetDelayed[vectorAngle[List[Pattern[a1,Blank[]],Pattern[a2,Blank[]]]],
Module[List[x,y],
CompoundExpression[
Set[List[x,y],
N[Times[List[a1,a2],
Power[Sqrt[Plus[Power[a1,2],Power[a2,2]]],-1]]]],
If[Equal[x,0],
If[SameQ[Sign[y],1],Times[p,Power[2,-1]],
Times[Times[-1,p],Power[2,-1]]],
If[Equal[y,0],If[SameQ[Sign[x],1],0,p],
If[SameQ[Sign[y],1],ArcCos[x],
Plus[Times[2,p],Times[-1,ArcCos[x]]]]]]]]]
In the latter, it uses a full nested form (called FullForm in
Mathematica). This form is isomorphic to lisp's nested parenthesis
syntax, token for token (i.e. lisp's (f a b) is Mathematica's
f[a,b]). As you can see, this form, by the sheer number of nested
brackets, is in practice problematic to read and type. In Mathematica,
nobody really program using this syntax. (The FullForm syntax is
there, for the same reason of language design principle shared with
lisp of consistency and simplicity, or the commonly touted lisp
advantage of data is program; program is data.)
The third issue, about how nested syntax seriously discourages
frequent or advanced use of inline function sequencing on the fly, is
the most important and I'll give further explanation below.
One practical way to see how this is so, is by considering unix's
shell syntax. You all know, how convenient and powerful is the unix's
pipes. Here are some practical example: ls -al | grep xyz, or cat a
b c | grep xyz | sort | uniq.
Now suppose, we get rid of the unix's pipe notation, instead, replace
it with a pure functional notation: e.g. (uniq (sort (grep xyz (cat a
b c)))), or enrich it with a composition function and a pure function
construct (?), so this example can be written as: ((compose (lambda
(x) (grep xyz x)) sort uniq) (cat a b c)).
You see, how this change, although syntactically equivalent to the
pipe | (or semantically equivalent in the example using function
compositions), but due to the cumbersome nested syntax, will force a
change in the nature of the language by the code programer produces.
Namely, the frequency of inline sequencing of functions on the fly
will probably be reduced, instead, there will be more code that define
functions with temp variables and apply it just once as with
traditonal languages.
A language's syntax or notation system, has major impact on what kind
of code or style or thinking pattern on the language's users. This is
a well-known fact for those acquainted with the history of math
notations.
The sequential notation f@g@h@x, or x//h//g//f, or unixy x|h|g|
f, are far more convenient and easier to decipher, than (f (g (h
x))) or ((compose h g f) x). In actual code, any of the f, g, h
might be a complex pure function (aka lambda construct, full of
parenthesis themselves).
Lisp, by sticking with almost uniform nested parenthesis notation, it
immediately reduces the pattern of sequencing functions, simply
because the syntax does not readily lend the programer to it as in the
unix's x|h|g|f. For programers who are aware of the coding pattern
of sequencing functions, now either need to think in terms of a
separate composition construct, and or subject to the much
problematic typing and deciphering of nested parenthesis.
(Note: Lisp's sexp is actually not that pure. It has ad hoc syntax
equivalents such as the quote construct '(a b c) , and also `,
#, ,@ constructs, precisely for the purpose of reducing
parenthesis and increasing readability. Scheme's coming standard the
R6RS ?, even proposes the introduction of [] and {} and few other
syntax sugars to break the uniformity of nested parenthesis for
legibility. Mathematica's FullForm, is actually a pure nested notation
as can be.)
-------
The above, is part of a 3-part exposition:
The Concepts and Confusions of Prefix, Infix, Postfix and Fully
Functional Notations,
Prefix, Infix, Postfix notations in Mathematica,
How Lisp's Nested Notation Limits The Language's Utility,
archived at:
http://xahlee.org/UnixResource_dir/writ/notations.html
Xah
x@xahlee.org
? http://xahlee.org/
On May 4, 5:11pm, Xah Lee <x@xahlee.org> wrote:
> How Lisp's Nested Notation Limits The Language's Utility > Xah Lee, 2007-05-03
> There is a common complain by programers about lisp's notation, of
> nested parenthesis, being unnatural or difficult to read.
the complaints occured by the entire population of complaintive
programmers.
> (1) Some 99% of programers are not used to the nested parenthesis
> syntax. This is a practical problem.
Since 99% of programmers don't use Lisp, it's not a practical problem.
> (2) Arguably, the pure nested syntax is not natural for human to read.
> Long time lispers may disagree on this point.
Programming language syntax shouldn't be natural for humans to read.
Or, rather, this shouldn't be a requirement which creates technical
compromises.
> (3) Most importantly, a pure nested syntax discourages frequent or
> advanced use of function sequencing or compositions.
That is an artifact of the way in which function composition is
rendered in nested syntax, and not an artifact of that syntax itself.
There exist macros that provide alternate syntax for function
composition, such as a left-to-right pipeline.
> This aspect is the most devastating.
Compared to issues like global warming and problems in the Middle
East, hardly.
> The first issue, that most programers are not comfortable with nested
> notation, is well known.
Many programmers are also not comfortable in social situations. So
what?
> shell syntax. You all know, how convenient and powerful is the unix's > pipes. Here are some practical example: ls -al | grep xyz, or cat a > b c | grep xyz | sort | uniq. > Now suppose, we get rid of the unix's pipe notation, instead, replace
> it with a pure functional notation: e.g. (uniq (sort (grep xyz (cat a
> b c)))),
details. These programs pass their output to each other, but they also
have a return value (termination status) which isn't passed through
the pipeline. And they take arguments, but the arguments of a pipeline
element are not derived from the previous pipeline element.
Your call (grep xyz (cat ...)) means to pass the output of cat as the
third argument of grep.
In the POSIX shell, this would be coded using guess what, Lisp-like
syntax:
grep xyz $(cat ...)
Taking it further:
uniq $(sort $(grep xyz $(cat a b c)))
or enrich it with a composition function and a pure function
> construct (?), so this example can be written as: ((compose (lambda
> (x) (grep xyz x)) sort uniq) (cat a b c)).
I posted a filter macro in comp.lang.lisp which expresses function
chaining into a left-to-right notation. Look for it.
In this notation, you might write:
(filter 3 (expt _ 2) (* 4))
which means, start with 3, raise it to the power of 2 to obtain 9, and
then multiply by 4 to get 36.
The underscore indicates the argument position where the output of the
previous pipeline element is to be inserted when calling the next
pipeline element. The default is to add it as a rightmost argument.
The macro has features for dealing with splitting and recombining
lists, and handling multiple values.
This is still the same ``pure nested'' syntax; it merely expresses
function chaining differently.
What was that about notation limiting language utility?
Xah Lee wrote: > vectorAngle[{a1_, a2_}] := Module[{x, y}, > {x, y} = {a1, a2}/Sqrt[a1^2 + a2^2] // N; > If[x == 0, If[Sign@y === 1, ?/2, -?/2], > If[y == 0, If[Sign@x === 1, 0, ?], > If[Sign@y === 1, ArcCos@x, 2 ? - ArcCos@x] > ] > ] > ] > SetDelayed[vectorAngle[List[Pattern[a1,Blank[]],Pattern[a2,Blank[]]]],
> Module[List[x,y],
> CompoundExpression[
> Set[List[x,y],
> N[Times[List[a1,a2],
> Power[Sqrt[Plus[Power[a1,2],Power[a2,2]]],-1]]]],
> If[Equal[x,0],
> If[SameQ[Sign[y],1],Times[?,Power[2,-1]],
> Times[Times[-1,?],Power[2,-1]]],
> If[Equal[y,0],If[SameQ[Sign[x],1],0,?],
> If[SameQ[Sign[y],1],ArcCos[x],
> Plus[Times[2,?],Times[-1,ArcCos[x]]]]]]]]]
syntax is good. In particular, it does an excellent job of mimicking
conventional mathematical notation. Arguing in favor of Lisp syntax is like
advocating the use of cave painting...
Also, note that Mathematica provides strictly more in the way of macros.
--
Dr Jon D Harrop, Flying Frog Consultancy
The F#.NET Journal
http://www.ffconsultancy.com/products/fsharp_journal/?usenet
Kaz Kylheku wrote: > On May 4, 5:11pm, Xah Lee <x @xahlee.org> wrote: >> (1) Some 99% of programers are not used to the nested parenthesis >> syntax. This is a practical problem. > Since 99% of programmers don't use Lisp, it's not a practical problem.
problem". However, the problem extends beyond Lisp.
Recent discussions have covered the use of pattern matching. In SML, OCaml,
Haskell (I believe) and F# you must write pattern matches over the expr
type in prefix notation. To borrow from Alan's example, the Lisp code:
(destructuring-bind (op1 (op2 n x) y) form
`(* ,n (* ,(simplify x) ,(simplify y)))))
((cons (eql *) *)
(destructuring-bind (op left right) form
(list op
(simplify left)
(simplify right))))
((cons (eql +)
(cons (eql 0)
(cons * null)))
could be written:
| n*x*y -> n*(x*y)
but in ML this must be written as a pattern match over a sum type where the
type constructors must use prefix notation:
| Mul(Mul(n, x), y) -> Mul(n, Mul(x, y))
While this is clearly much better than the Lisp, it would be preferable to
use the mathematical syntax in this case. You can address this in OCaml
using macros and there is a chance that F# will support overloaded
operators in patterns in the future.
Mathematica lets you do:
n x y -> n (x y)
but I don't know of any other languages that do, without forcing you to
reinvent the wheel via macros.
--
Dr Jon D Harrop, Flying Frog Consultancy
The F#.NET Journal
http://www.ffconsultancy.com/products/fsharp_journal/?usenet
Xah Lee <x @xahlee.org> writes: > How Lisp's Nested Notation Limits The Language's Utility
limitations of the tools one chooses or is forced to use. If more
people were open to the flaws in their OS, religion, editor, and a
myriad of other things the world would surely be a better and more
peaceful place. However, I have to say that all I ever see from you,
Mr. Lee, is complaints and how you want emacs and lisp to change. For
the love of whatever god you choose to pray to, find a frigging tool
that makes you happy. If it is emacs that makes you happy, then change
the things you don't like and be happy but I fail to see how your
whining diatribes serve any useful purpose. If you don't like lisp then
by all means use something else.
No offense but it does get old after a while.
--
Robert D. Crawford r@comcast.net
Marriage is learning about women the hard way.
"Robert D. Crawford" <r@comcast.net> writes:
> If it is emacs that makes you happy, then change the things you don't
> like and be happy but I fail to see how your whining diatribes serve
> any useful purpose. If you don't like lisp then by all means use
> something else.
Xahlee likes to complain. That's the main factor here.
-Miles
--
Run away! Run away!
> (1) Some 99% of programers are not used to the nested parenthesis
> syntax. This is a practical problem. On this aspect along, lisp's
> syntax can be considered a problem.
The first time I saw graph-theory notation, I thought it was
gibberish. I still think most mathematical notation is gibberish, but
I deal with it --- I don't turn in proofs written in prose.
> (2) Arguably, the pure nested syntax is not natural for human to read.
> Long time lispers may disagree on this point.
And mathematical notation is not natural for people to read, at least
not anybody who grew up learning a natural language. But people deal
with it. They're remarkably adaptable this way.
> vectorAngle[{a1_, a2_}] := Module[{x, y},
> {x, y} = {a1, a2}/Sqrt[a1^2 + a2^2] // N;
> If[x == 0, If[Sign@y === 1, p/2, -p/2],
> If[y == 0, If[Sign@x === 1, 0, p],
> If[Sign@y === 1, ArcCos@x, 2 p - ArcCos@x]
> ]
> ]
> ]
Speaking of gibberish. I can't believe anybody would hold up
Mathematica as an example of good programming. Next you'll be telling
me that 99% of Matlab code isn't really crap!
> The third issue, about how nested syntax seriously discourages
> frequent or advanced use of inline function sequencing on the fly, is
> the most important and I'll give further explanation below.
I consider this to be a Good Thing (TM). Unix shell commands read like
line noise.
Xah Lee <x @xahlee.org> writes: > How Lisp's Nested Notation Limits The Language's Utility > Xah Lee, 2007-05-03
> There is a common complain by programers about lisp's notation, of
> nested parenthesis, being unnatural or difficult to read. Long time
> lisp programers, often counter, that it is a matter of conditioning,
> and or blaming the use of inferior text editors that are not
> designed to display nested notations. In the following, i describe how
> lisp notation is actually a problem, in several levels.
rather interpret the code according to the indentation.
> (1) Some 99% of programers are not used to the nested parenthesis
> syntax. This is a practical problem. On this aspect along, lisp's
> syntax can be considered a problem.
It's certainly different. Whether it is a problem or not depends on
personal or subjective criteria.
> (2) Arguably, the pure nested syntax is not natural for human to read.
> Long time lispers may disagree on this point.
Harder to read for some things, easier to read for others.
E.G.
1 + 2 + 3 + 4 + 6 - 3 + 32
or
(- (+ 1 2 3 4 6 32) 3)
> (3) Most importantly, a pure nested syntax discourages frequent or
> advanced use of function sequencing or compositions. This aspect is
> the most devastating.
This is one reason LISP has macros. Don't like the syntax? Make your
own. How many languages make this as easy as LISP does?
> The third issue, about how nested syntax seriously discourages > frequent or advanced use of inline function sequencing on the fly, > is the most important and I'll give further explanation below. > One practical way to see how this is so, is by considering unix's
> shell syntax. You all know, how convenient and powerful is the
> unix's pipes. Here are some practical example: ls -al | grep xyz,
> or cat a b c | grep xyz | sort | uniq.
> Now suppose, we get rid of the unix's pipe notation, instead,
> replace it with a pure functional notation: e.g. (uniq (sort (grep
> xyz (cat a b c)))), or enrich it with a composition function and a
> pure function construct (?), so this example can be written as:
> ((compose (lambda (x) (grep xyz x)) sort uniq) (cat a b c)).
'Nuff said.
UNIX pipe `|' is not just a throw-away syntactic separator, anyone
with LISP experience would see it for what it is: a function that
operates on functions.
> Lisp, by sticking with almost uniform nested parenthesis notation,
> it immediately reduces the pattern of sequencing functions, simply
> because the syntax does not readily...<snip>
I would contend that LISP did not do this. You did.
<snip>
> (Note: Lisp's sexp is actually not that pure. It has ad hoc syntax
> equivalents such as the quote construct '(a b c) , and also
> `, #, ,@ constructs, precisely for the purpose of reducing
> parenthesis and increasing readability. Scheme's coming standard the
> R6RS ?, even proposes the introduction of [] and {} and few other
> syntax sugars to break the uniformity of nested parenthesis for
> legibility. Mathematica's FullForm, is actually a pure nested
> notation as can be.)
Some functions are used so often, they have shorthand equivalents.
This is a feature in many languages. But if for some reason one
wanted the sexp to be "pure," nothing's stopping him from using the
fully-parenthesized versions.
> ------- > The above, is part of a 3-part exposition: > The Concepts and Confusions of Prefix, Infix, Postfix and Fully > Functional Notations, > Prefix, Infix, Postfix notations in Mathematica, > How Lisp's Nested Notation Limits The Language's Utility, > archived at: > http://xahlee.org/UnixResource_dir/writ/notations.html > Xah
> x@xahlee.org
> ? http://xahlee.org/
far into the exposition:
http://gigamonkeys.com/book/
--
Edward
> \|||/
> (o o)
> |~~~~ooO~~(_)~~~~~~~|
> | Please |
> | don't feed the |
> | TROLL! |
> '~~~~~~~~~~~~~~Ooo~~'
> |__|__|
> || ||
> ooO Ooo
Xah Lee wrote:
(1) Some 99% of programers are not used to the nested parenthesis
syntax. This is a practical problem. On this aspect along, lisp's
syntax can be considered a problem.
Ken Tilton wrote:
Simply wrong. What would be a problem would be if they tried it and
could not quickly get used to it.
I think what you said is part of what i said. But let me elaborate.
Lisp's nested parenthesis certainly is a problem, if you want to
attract programers to lisp and programers are not attracted by sexp in
the first place.
What you expressed, is to consider the question of whether people can
get used to sexp. If programers cannot adapt sexp and find it
comfortable as a syntax of a programing language, then, you consider
THAT, to be a problem of the lisp syntax. Otherwise no problemo.
I think you vantage point is not so goody. But if we consider the
question itself, i think yes, people can adapt and use sexp reasonable
well for programing. Actually, this has been already done i guess by
lispers for 40+ years right? But if we really focus on this point of
view, namely: whether sexp can be suitable as a syntax for computing
language. Then, that is rather not a interesting question i thinky.
Because, in general, people can adapt to all kind of wierd shits,
really depending how pressing the matter is. If it is life
threatening, or they have no other choice, human animals can adapt.
Imagine, compare, the technology today are far advanced than 40 years
ago. Computers are what? a thousand, ten thousand times faster? And
there's no Perl, Python, Java, Internet 40 years ago. But People went
to the Moon! Imagine, what kind of torturous pain these people have
to go thru in software and hardware or the computation of mathematics
to do this. BASIC with GOTO and FORTRAN? What? no structured
constructs? No code blocks? No libraries? No symbols? No macros? Not
even Eval()? No USB and DVDs but punchcards?
You know about Chinese characters right? To a European, Chinese
characters looks torturous. But in fact it is. Just consider the
number of strokes. But i think Chinese people of 13 billion are
surviving.
Sure. I certainly agree human animals can get used to sexp. Under
some conditions, human animals can get used to a lot of things, and
loving it too.
See:
Body and Mind Modification
http://xahlee.org/Periodic_dosage_dir/20031129_body_mod.html
Difficulty Perceptions in Human Feats
http://xahlee.org/vofli_bolci/juggling.html
The interesting question would be, to what degree of botchedness of
computer language syntax can be, until programers will not be able to
adapt it and code it fruitfully? Suppose, for each paren in lisp, we
double it. So, (+ 3 4) will be written as ((+ 3 4)). And suppose
we force this to be the new syntax for lisp. I will bet you one
hundred bucks, that all lispers will find in exactly as easy to read
as before.
How many level of parens do you think we can add till all lispers
abandon ship?
How many?
----------------------------
Xah Lee wrote:
(2) Arguably, the pure nested syntax is not natural for human to
read. Long time lispers may disagree on this point.
Kenny wrote:
No code is natural to read, and yes, I have written a ton of COBOL.
Neither are legal or scholarly natural language texts natural to
read.
Huh? surely you agree that there is at least some qualification as to
some written language being more natural or easier to read?
For example, compare language A and B, where A is just lisp's sexp,
and B is sexp with every paren replaced by double parens. Now, which
is more natural or easy to read?
So, likewise, compare Perl and Python. Which is easier to read in
general? You can't wax philosophy on this can you?
Imagine a philosophical scenario, where a devil killed off all
pythoners on earth. Therefore perl code is easier to read, because
nobody would understand a fuck when shown a python code. So, the
question of whether Perl or Python code is easier to read, depends.
Also, i mean, it depends on the programer!! Because, if i write Perl
code versus a moron writing in Python, then my Perl code will sure be
easier to read. So, it also depends on me.
What a great tough undecidability!
----------------------------
Xah Wrote:
(3) Most importantly, a pure nested syntax discourages frequent or
advanced use of function sequencing or compositions. This aspect is
the most devastating.
Kenny wrote:
The example you chose was a command line, where conciseness rules and
where one is not likely to encounter refactoring or macros. ie, the
syntax for a command-line has nothing to do with the syntax for
serious programming.
Yes the example i gave was unix's shell. It is chosen because it is
simple to illustrate and widely known.
I could give Mathematica examples with explanations... but its not
suitable as the simple unix pipe example because then i'll have to
spend great space explaining Mathematica.
(if anyone is interested in Mathematica syntax, i explained some here
http://xahlee.org/UnixResource_dir/writ/notations.html
)
But anyway, here's a few mathematica example from my Plane Tiling
package.
Here's one line that's the most simple to understand:
Reflect2DGraphics[{a1_, a2_}, {n1_, n2_}][gra_] :=
(Translate2DGraphics[{n1, n2}])@
(Reflect2DGraphics[{a1,a2}])@
(Translate2DGraphics[-{n1, n2}][gra]);
Basically, you'll see on the right side are 3 sequence of functions.
The left side is a function applied to a function. i.e.
Reflect2DGraphics takes 2 vectors and returns a function that takes
one graphics argument. (it doesn't actually return a function since
it's written as pattern matching... but you can think of it as a
function generator)
Here's the lispy form some lisper believe is easier to read:
CompoundExpression[
SetDelayed[
Reflect2DGraphics[List[Pattern[a1, Blank[]], Pattern[a2,
Blank[]]],
List[Pattern[n1, Blank[]], Pattern[n2, Blank[]]]][
Pattern[gra, Blank[]]],
Translate2DGraphics[List[n1, n2]][
Reflect2DGraphics[List[a1, a2]][
Translate2DGraphics[Times[-1, List[n1, n2]]][gra]]]], Null]
The following are more code. They involve pure functions, function
application, function mapping, function generator applied to
functions... and basically all done with flat sequencing of functions
when possible. (aka function chaining sans nesting). Whenever you see
the ampersand sign &, its a pure function (aka lambda). Some pure
function has pure function as its innards.
These are written in 1997, by yours truely. I would say, if you have
not been coding lisp or Mathematica for, say, 40 hours a week for 4
years, you wouldn't understand these code when explained. (not
considering the math it is doing)
Okie, here's a good one. Lots of sequencing of pure functions on the
fly:
cycledMatrix[{m_Integer, n_Integer}, cycleLists : {_List ..}] :=
Module[{}, (Flatten[({Table[#1, {Quotient[#2, #3]}],
Take[#1, Mod[#2, #3]]} &) @@ ({#, m,
Length@#} &)@#] &) /@
Flatten[(({(Flatten[#, 1] &)@Table[#1, {Quotient[#2, #3]}],
Take[#1, Mod[#2, #3]]} &) @@ ({#, n, Length@#} &)@
cycleLists), 1]];
Btw, the f@@g you see is shortcut syntax for Apply[f,g].
Here's the equivalent lispy form, lispers think its easier to read:
CompoundExpression[
SetDelayed[
cycledMatrix[
List[Pattern[m, Blank[Integer]], Pattern[n, Blank[Integer]]],
Pattern[cycleLists, List[Repeated[Blank[List]]]]],
Module[List[],
Map[Function[
Flatten[Apply[
Function[
List[Table[Slot[1], List[Quotient[Slot[2],
Slot[3]]]],
Take[Slot[1], Mod[Slot[2], Slot[3]]]]],
Function[List[Slot[1], m, Length[Slot[1]]]]
[Slot[1]]]]],
Flatten[Apply[
Function[
List[Function[Flatten[Slot[1], 1]][
Table[Slot[1], List[Quotient[Slot[2],
Slot[3]]]]],
Take[Slot[1], Mod[Slot[2], Slot[3]]]]],
Function[List[Slot[1], n, Length[Slot[1]]]]
[cycleLists]], 1]]]],
Null]
----------------------------------------
Okie, another one, wee!
ColoredLatticeNetwork[n:(4 | 3), m_Integer,
colors:{_List..}, s_, a_, {x_, y_}] :=
Module[{lines, gp}, lines = (Map[Line, #1, {2}] & )[
(Partition[#1, 2, 1] & ) /@
N[Table[{1, 0}*s*i + ({Cos[#1], Sin[#1]} & )[
(2*Pi)/n]*s*j, {j, -m, m}, {i, -m, m}]]];
gp = (Transpose[#1, {3, 1, 2}] & )[
{cycledMatrix[{m*2, m*2 + 1}, (RotateRight[#1, m] & )[
(RotateRight[#1, m] & ) /@ colors]], lines}];
Translate2DGraphics[{x, y}][
Table[Rotate2DGraphics[{0, 0}, ((2*Pi)*i)/n + a][
gp], {i, 0, n - 1}]]];
Here's the equivalent lispy form lisp morons insist it is easier to
read:
CompoundExpression[
SetDelayed[
ColoredLatticeNetwork[Pattern[n, Alternatives[4, 3]],
Pattern[m, Blank[Integer]],
Pattern[colors, List[Repeated[Blank[List]]]], Pattern[s,
Blank[]],
Pattern[a, Blank[]], List[Pattern[x, Blank[]], Pattern[y,
Blank[]]]],
Module[List[lines, gp],
CompoundExpression[
Set[lines,
Function[Map[Line, Slot[1], List[2]]][
Map[Function[Partition[Slot[1], 2, 1]],
N[Table[
Plus[Times[List[1, 0], s, i],
Times[Function[List[Cos[Slot[1]], Sin[Slot[1]]]]
[
Times[Times[2, Pi], Power[n, -1]]], s, j]],
List[j, Times[-1, m], m], List[i, Times[-1, m],
m]]]]]],
Set[gp, Function[Transpose[Slot[1], List[3, 1, 2]]][
List[cycledMatrix[List[Times[m, 2], Plus[Times[m, 2],
1]],
Function[RotateRight[Slot[1], m]][
Map[Function[RotateRight[Slot[1], m]], colors]]],
lines]]],
Translate2DGraphics[List[x, y]][
... read more »
"Miles Bader" <m @gnu.org> wrote in message
> "Robert D. Crawford" <r @comcast.net> writes: >> If it is emacs that makes you happy, then change the things you don't >> like and be happy but I fail to see how your whining diatribes serve >> any useful purpose. If you don't like lisp then by all means use >> something else. > Xahlee likes to complain. That's the main factor here.
in both the good and the bad sense of the term, and rather eccentric.
--
Free games and programming goodies.
http://www.personal.leeds.ac.uk/~bgy1mm
"Kaz Kylheku" <kkylh @gmail.com> wrote in message
On May 4, 5:11 pm, Xah Lee <x@xahlee.org> wrote:
>> How Lisp's Nested Notation Limits The Language's Utility >> (2) Arguably, the pure nested syntax is not natural for human to read. >> Long time lispers may disagree on this point. >Programming language syntax shouldn't be natural for humans to read.
>Or, rather, this shouldn't be a requirement which creates technical
>compromises.
technical compromises whatsoever - pure assembly or machine code - but only
rarely. Most of the time we accept some limitations for the sake of making
things easier for the human programmer. That includes run-time efficiency,
but also restrictions in the "power" of the language.
You might be interested in the page 10 Rules of Computer Programming on my
website which deals with psychological issues in programming. Lisp breaks
the rule of three in spades.
--
Free games and programming goodies.
http://www.personal.leeds.ac.uk/~bgy1mm
Xah Lee wrote: > How Lisp's Nested Notation Limits The Language's Utility > Xah Lee, 2007-05-03
> There is a common complain by programers about lisp's notation, of
> nested parenthesis, being unnatural or difficult to read. Long time
> lisp programers, often counter, that it is a matter of conditioning,
> and or blaming the use of inferior text editors that are not
> designed to display nested notations. In the following, i describe how
> lisp notation is actually a problem, in several levels.
> (1) Some 99% of programers are not used to the nested parenthesis
> syntax. This is a practical problem. On this aspect along, lisp's
> syntax can be considered a problem.
inanimate, dispassionate, virtual concept which doesn't (cannot!) "care"
whether it is used at all.
Only people can have problems with something. For example, programmers
who want some of the cool features of Lisp but don't want to put up with
its syntax.
However, for decades, there have been programmers who have learned to
prefer Lisp's syntax over anything else. As long as they continue to
exist, Lisp dialects will continue to exist. Those people don't have a
problem - to the contrary.
Leave them alone - they are happy with their choice.
If you don't like Lisp, there are numerous attempts to copy its features
using other surface syntaxes. Just pick one.
Pascal
--
My website: http://p-cos.net
Common Lisp Document Repository: http://cdr.eurolisp.org
Closer to MOP & ContextL: http://common-lisp.net/project/closer/
"Malcolm McLean" <regniz @btinternet.com> writes: > "Miles Bader" <m @gnu.org> wrote in message > news:873b2cxbxt.fsf@catnip.gol.com... >> "Robert D. Crawford" <r @comcast.net> writes: >>> If it is emacs that makes you happy, then change the things you don't >>> like and be happy but I fail to see how your whining diatribes serve >>> any useful purpose. If you don't like lisp then by all means use >>> something else. >> Xahlee likes to complain. That's the main factor here.
> There is thought and intelligence in his posts. However they are
> provocative in both the good and the bad sense of the term, and rather
complaining about parenthesis in lisp every 3 months and the arguments
never get any better or new. Rehashing all that once again doesn't
attest to "thought and intelligence" but rather to a trollish streak.
Regards -- Markus
Rayiner Hashem <rayi @gmail.com> writes: >> (1) Some 99% of programers are not used to the nested parenthesis >> syntax. This is a practical problem. On this aspect along, lisp's >> syntax can be considered a problem. > The first time I saw graph-theory notation, I thought it was
> gibberish. I still think most mathematical notation is gibberish, but
> I deal with it --- I don't turn in proofs written in prose.
>> (2) Arguably, the pure nested syntax is not natural for human to read.
:-)
>> Long time lispers may disagree on this point. > And mathematical notation is not natural for people to read, at least
> not anybody who grew up learning a natural language. But people deal
> with it. They're remarkably adaptable this way.
Markus E Leypold
<development-2006-8ecbb5cc8aREMOVET @ANDTHATm-e-leypold.de> writes: > Where is the good sense in there? We have (at c.l.f) people > complaining about parenthesis in lisp every 3 months and the arguments > never get any better or new. Rehashing all that once again doesn't > attest to "thought and intelligence" but rather to a trollish streak.
_1950s_! Lisp still has the parens, and there are good reasons for that.
-Miles
--
[|nurgle|] ddt- demonic? so quake will have an evil kinda setting? one that
will make every christian in the world foamm at the mouth?
[iddt] nurg, that's the goal
"Malcolm McLean" <regniz @btinternet.com> writes: > You might be interested in the page 10 Rules of Computer Programming on > my website which deals with psychological issues in programming. Lisp > breaks the rule of three in spades.
-Miles
--
o The existentialist, not having a pillow, goes everywhere with the book by
Sullivan, _I am going to spit on your graves_.
"Malcolm McLean" <regniz @btinternet.com> writes: > You might be interested in the page 10 Rules of Computer Programming > on my website which deals with psychological issues in > programming. Lisp breaks the rule of three in spades.
suck also. If your "Refutation of Common Atheist Arguments" have a
similar quality, the atheists will have a field day.
Regards -- Markus
Markus E Leypold wrote: > "Malcolm McLean" <regniz @btinternet.com> writes: >>You might be interested in the page 10 Rules of Computer Programming
>>on my website which deals with psychological issues in
>>programming. Lisp breaks the rule of three in spades.
> Rule three is about indirection, not about nesting. The other rules
> suck also. If your "Refutation of Common Atheist Arguments" have a
> similar quality, the atheists will have a field day.
arguments are offered by the same person. Both religious belief and a
belief in the essential importance of syntactic sugar require abandoning
Occam's Razor.
Anton
Dear Pascal moron,
Xah Lee wrote:
(1) Some 99% of programers are not used to the nested parenthesis
syntax. This is a practical problem. On this aspect along, lisp's
syntax can be considered a problem.
Pascal Costanza wrote:
Lisp doesn't have a problem here. Lisp is a programming language, an
inanimate, dispassionate, virtual concept which doesn't (cannot!)
"care" whether it is used at all. Only people can have problems with
something. For example, programmers who want some of the cool features
of Lisp but don't want to put up with its syntax.
You are actually wrong here, because, people can't have a problem.
People are animals, made of meat. They can have a problem when, they
get sick, and their body will disfunction or function abnormally. So,
for example, even sexp has all the problems, lisp morons are still
fine.
Pascal fuckhead wrote:
However, for decades, there have been programmers who have learned to
prefer Lisp's syntax over anything else. As long as they continue to
exist, Lisp dialects will continue to exist. Those people don't have a
problem - to the contrary.
existence?
my god... you are quite desperate.
In this thread, a few people already started to post completely off
topic, brainless, pure personal attacks. I think you are still good.
Sometimes i have a problem telling, of those who post brainless things
to my articles, whether they are joking with wanton carelessness, or
if their critical thinking abilities is really that low.
For example, your reply is a good example. I wasn't sure, if you are
just fucking with me, or really, really meant your writing as a valid
argument to my thesis. In this thread, Ken Tilton, also wrote
something that's incredibly stupid. In fact, more or less repeating
what i said, just with antagonism and explicit denial. I take it, that
he acted that way probably because my essay is so cogent and powerful
that it hit a nerve and paralyzed his reasoning faculties and numbed
his nonchalant quip Muse.
There are some others in this thread, which are so hateful, fucking
full of the ugliness of humanity. The replies from Markus E Leypold is
a prime example. I wonder, outside of newsgroups, if he is just a
sophomoron at college.
Other posts in this thread, some sincere ones, are full utterly
fucking stupid drivels. (or i shall put the polite version: logical
fallacies) The level is so low that i'm really ashamed that they
really came out from the mouthes of a class of people in society who's
jobs are to program computers.
(in this regard, see:
The Condition of Industrial Programers
http://xahlee.org/UnixResource_dir/writ/it_programers.html
)
For example, there's this gem: Programming language syntax shouldn't
be natural for humans to read. Or, rather, this shouldn't be a
requirement which creates technical compromises.
I think this quote or the concept of it has been around for a while.
If you take it seriously, it's full of MOTHERFUCKING nonsensical,
meaningless, shit. It amounts to a sound bite. Behind it, it wants to
make programers, in particular the elite programers like the lisp
fuckers, to think something along the line: my syntax is so bizarre
because i'm superior.
I guess it's lisper's version of The three chief virtues of a
programmer are: Laziness, Impatience and Hubris.
Pascal Costanza moron wrote:
Leave them alone - they are happy with their choice.
If you don't like Lisp, there are numerous attempts to copy its
features
using other surface syntaxes. Just pick one.
Try, perhaps, learn to calm down yourself. You are not under attack.
Lisp the language, is not under attack by my essay. My article,
although cogently detailed why lisp syntax is a serious problem at
several levels, it does not mean that, it is no good in some
absolute way. Also, it is far better, then essentially all imperative
language's syntaxes. Even, one can logically agree with my article,
and remain positive, because although lisp perhaps reduce the use of
function sequencing, but that by itself is not necessarily a very bad
thing. Because, function sequencing (aka chaining), although a very
important paradigm, is not necessarily the only way to program, nor
the only way for functional programing. Consider, even today in the
light of OOP. And Common Lisp, in particular, isn't all that much
concerned about purity of functional programing anyway. So logically,
from this perspective or argument, my essay isn't a damning
certificate.
I'm really sorry i have to say the above paragraph, as if like a pat
on the back to some crying pussies. But the juvenility, sensitivity,
ignorance, and stupidity, as shown in the responses in this thread,
made me.
I was hoping, perhaps due to my clear exposition of the sexp problem
for perhaps the first time, that we could move on to other fruitful
discussions, not necessarily agree that it is a problem. For example,
LOGO, DyLan, Arc all abandoned the nested fuck. I mean, lispers may
disagree, but the people behind these LISP languages are not brainless
fuckheads, are they? Alternatively, i was hoping, perhaps there will
be fruitful discussions in the direction of technical issues of
transforming syntax. i.e. of Mathematica's f[a,b] and lisp's (f a b).
Or, perhaps some technically knowledgable people here (there are many)
can by ways of chat, impart some insight about some technical
connections between syntaxes and semantic (apart from myself). For
example, DyLan i believe once was believed to have have sexp
underneath. If so, that would be interesting because it gives us a
actual, existing, example of a lang with sexp underneath alternative
to Mathematica's ways. But also, lisp can actually relatively easily,
create a layer of syntax on top of sexp...
Really, you people need to learn. Be calm. Keep your mind open. I'm
not attacking you or attacking lisp. If there's any attacking, it is
your immature and unhealthy nerve.
PS By the way, i also responded a article recently about why Perl and
Python programers today should learn lisp.
(
Why learn lisp when there are python and perl?, Xah Lee, 2007-05-03.
http://xahlee.org/UnixResource_dir/writ/wl_lisp.html
)
Can a lisper write a open letter thanking me for that please?
Xah
x@xahlee.org
? http://xahlee.org/
On May 5, 1:11 am, Xah Lee <x@xahlee.org> wrote:
> How Lisp's Nested Notation Limits The Language's Utility
Very good. Now, off you go and design and implement an alternative
syntax. It's easy, it's been done hundreds of times. I think I have
two or three limited examples on my web site and several more I never
bothered publishing. There must, as I say, be hundreds of examples
around and probably thousands when you count all the non-published
ones. So pick the best and use them, or, since you're by far the
smartest person here, why not come up with your own? Jon Harrop can
probably help you.
I think *you* need to cool down Xah Lee. I agree it can be annoying
if you make a critical analysis of Lisp and people attack *you*. This
is called an ad hominem argument, and, sadly, they are all too common
on usenet. But calling people names like 'moron' is not the right
way to win hearts and minds. You say some interesting things but you
play into the hands of your critics by launching personal attacks.
Now you will probably get a load more posts attacking your bad manners
and so your original points are lost in the scrum and people write you
off as a troll.
Be cool and if you do think someone is using ad hominem arguments;
tersely point it out and return to the main points. Don't get
abusive.
Mark
On 5 May, 16:52, Xah Lee <x@xahlee.org> wrote:
> Dear Pascal moron, > Xah Lee wrote:
> (1) Some 99% of programers are not used to the nested parenthesis
> syntax. This is a practical problem. On this aspect along, lisp's
> syntax can be considered a problem.
> Pascal Costanza wrote:
> Lisp doesn't have a problem here. Lisp is a programming language, an
> inanimate, dispassionate, virtual concept which doesn't (cannot!)
> "care" whether it is used at all. Only people can have problems with
> something. For example, programmers who want some of the cool features
> of Lisp but don't want to put up with its syntax.
> You are actually wrong here, because, people can't have a problem.
> People are animals, made of meat. They can have a problem when, they
> get sick, and their body will disfunction or function abnormally. So,
> for example, even sexp has all the problems, lisp morons are still
> fine.
> Pascal fuckhead wrote:
> However, for decades, there have been programmers who have learned to
> prefer Lisp's syntax over anything else. As long as they continue to
> exist, Lisp dialects will continue to exist. Those people don't have a
> problem - to the contrary.
> existence?
> my god... you are quite desperate.
> In this thread, a few people already started to post completely off
> topic, brainless, pure personal attacks. I think you are still good.
> Sometimes i have a problem telling, of those who post brainless things
> to my articles, whether they are joking with wanton carelessness, or
> if their critical thinking abilities is really that low.
> For example, your reply is a good example. I wasn't sure, if you are
> just fucking with me, or really, really meant your writing as a valid
> argument to my thesis. In this thread, Ken Tilton, also wrote
> something that's incredibly stupid. In fact, more or less repeating
> what i said, just with antagonism and explicit denial. I take it, that
> he acted that way probably because my essay is so cogent and powerful
> that it hit a nerve and paralyzed his reasoning faculties and numbed
> his nonchalant quip Muse.
> There are some others in this thread, which are so hateful, fucking
> full of the ugliness of humanity. The replies from Markus E Leypold is
> a prime example. I wonder, outside of newsgroups, if he is just a
> sophomoron at college.
> Other posts in this thread, some sincere ones, are full utterly
> fucking stupid drivels. (or i shall put the polite version: logical
> fallacies) The level is so low that i'm really ashamed that they
> really came out from the mouthes of a class of people in society who's
> jobs are to program computers.
> (in this regard, see:
> The Condition of Industrial Programershttp://xahlee.org/UnixResource_dir/writ/it_programers.html
> )
> For example, there's this gem: Programming language syntax shouldn't
> be natural for humans to read. Or, rather, this shouldn't be a
> requirement which creates technical compromises.
> I think this quote or the concept of it has been around for a while.
> If you take it seriously, it's full of MOTHERFUCKING nonsensical,
> meaningless, shit. It amounts to a sound bite. Behind it, it wants to
> make programers, in particular the elite programers like the lisp
> fuckers, to think something along the line: my syntax is so bizarre
> because i'm superior.
> I guess it's lisper's version of The three chief virtues of a
> programmer are: Laziness, Impatience and Hubris.
> Pascal Costanza moron wrote:
> Leave them alone - they are happy with their choice.
> If you don't like Lisp, there are numerous attempts to copy its
> features
> using other surface syntaxes. Just pick one.
> Try, perhaps, learn to calm down yourself. You are not under attack.
> Lisp the language, is not under attack by my essay. My article,
> although cogently detailed why lisp syntax is a serious problem at
> several levels, it does not mean that, it is no good in some
> absolute way. Also, it is far better, then essentially all imperative
> language's syntaxes. Even, one can logically agree with my article,
> and remain positive, because although lisp perhaps reduce the use of
> function sequencing, but that by itself is not necessarily a very bad
> thing. Because, function sequencing (aka chaining), although a very
> important paradigm, is not necessarily the only way to program, nor
> the only way for functional programing. Consider, even today in the
> light of OOP. And Common Lisp, in particular, isn't all that much
> concerned about purity of functional programing anyway. So logically,
> from this perspective or argument, my essay isn't a damning
> certificate.
> I'm really sorry i have to say the above paragraph, as if like a pat
> on the back to some crying pussies. But the juvenility, sensitivity,
> ignorance, and stupidity, as shown in the responses in this thread,
> made me.
> I was hoping, perhaps due to my clear exposition of the sexp problem
> for perhaps the first time, that we could move on to other fruitful
> discussions, not necessarily agree that it is a problem. For example,
> LOGO, DyLan, Arc all abandoned the nested fuck. I mean, lispers may
> disagree, but the people behind these LISP languages are not brainless
> fuckheads, are they? Alternatively, i was hoping, perhaps there will
> be fruitful discussions in the direction of technical issues of
> transforming syntax. i.e. of Mathematica's f[a,b] and lisp's (f a b).
> Or, perhaps some technically knowledgable people here (there are many)
> can by ways of chat, impart some insight about some technical
> connections between syntaxes and semantic (apart from myself). For
> example, DyLan i believe once was believed to have have sexp
> underneath. If so, that would be interesting because it gives us a
> actual, existing, example of a lang with sexp underneath alternative
> to Mathematica's ways. But also, lisp can actually relatively easily,
> create a layer of syntax on top of sexp...
> Really, you people need to learn. Be calm. Keep your mind open. I'm
> not attacking you or attacking lisp. If there's any attacking, it is
> your immature and unhealthy nerve.
> PS By the way, i also responded a article recently about why Perl and
> Python programers today should learn lisp.
> (
> Why learn lisp when there are python and perl?, Xah Lee, 2007-05-03.
> http://xahlee.org/UnixResource_dir/writ/wl_lisp.html
> )
> Can a lisper write a open letter thanking me for that please?
> Xah
> x@xahlee.org
> ?http://xahlee.org/
"Anton van Straaten" <a@appsolutions.com> wrote in message
news:WI1%h.2620$RX.788@newssvr11.news.prodigy.net...
> Markus E Leypold wrote: >> "Malcolm McLean" <regniz @btinternet.com> writes: >>>You might be interested in the page 10 Rules of Computer Programming
>>>on my website which deals with psychological issues in
>>>programming. Lisp breaks the rule of three in spades.
>> Rule three is about indirection, not about nesting. The other rules
>> suck also. If your "Refutation of Common Atheist Arguments" have a
>> similar quality, the atheists will have a field day.
> Perhaps it's not a coincidence that these two seemingly unrelated
> arguments are offered by the same person. Both religious belief and a
> belief in the essential importance of syntactic sugar require abandoning
> Occam's Razor.
reasons, without irritating a lot of Lispers.
A programming language is inherently a compromise between the needs of the
human programmer and the needs of the computer. That's why the 10 rules of
computer programming are all psychological rules. There are many other
things you need to know to program a computer, but they are documented with
the system. The difference is, if you break a psychological rule then the
program still works, but it is too difficult to maintain.
The rules are also ones which people might be tempted to break - obviously
writing code with no comments and one letter identifiers is a bad idea, but
people don't need to be told that, so it's not a rule.
The rule of three was written before I was familiar with Lisp, and so you
might say that Lisp is a counter-example. I don't think it is, because the
first thing that everyone says about Lisp is "I can't do with all those
parentheses". In fact Lisp programmers use indentation to try to impose
another hierarchy of structure on the program, something they wouldn't need
to do if humans could glance at a long expression and match up parentheses.
--
Free games and programming goodies.
http://www.personal.leeds.ac.uk/~bgy1mm
"Xah Lee" <x @xahlee.org> wrote in message
>For example, there's this gem: Programming language syntax shouldn't
>be natural for humans to read. Or, rather, this shouldn't be a
>requirement which creates technical compromises.
>I think this quote or the concept of it has been around for a while.
>If you take it seriously, it's full of --------- nonsensical,
>meaningless, ----. It amounts to a sound bite. Behind it, it wants to
>make programers, in particular the elite programers like the lisp
>-----, to think something along the line: my syntax is so bizarre
>because i'm superior.
Now I also disagreed with Kaz on that one. Compare my post with yours. and
consider why I had to delete some many words in quoting you. Who do you
think is more likely to convince Mr Kylheku that he is in error?
--
Free games and programming goodies.
http://www.personal.leeds.ac.uk/~bgy1mm
Mark Tarver wrote:
I think *you* need to cool down Xah Lee. I agree it can be annoying
if you make a critical analysis of Lisp and people attack *you*. This
is called an ad hominem argument, and, sadly, they are all too common
on usenet. ...
But calling people names like 'moron' is not the right way to win
hearts and minds....
Exactly. I've been using online forums since 1990. I've been using
newsgroups since maybe 1994. If i wanted to play politics, given my IQ
and my knowledge of computing, and great skill of composition, i might
be a fucknig George Bush by now, with a massive army of morons at my
commands, not like, the likes of some computing industry leaders.
Understand, politness, is a intrinsic element of politics. (and
politics, means power-struggle) Politness arose from the existance of
hostility and aggression. Without aggression, there is no politness.
One easy way to see this, is notice how the behavior of politeness is
inversly proportional to how close are the parties involved. There
will be little politness, between your sisters, wives, or parents.
There will be a huge politeness, when big stakes are involved between
unbound human animals.
The computing newsgroups, made of males, have been brawling just about
when it begin. Your few words on politness and lecturing, is one
additional off-topic drivel in its history. (though, i appreciate your
kindness and your knowledge)
In this thread, i did not start four-letter words before NUMEROUS
fuckheads began sprouting purely unreasonable, totally off-topic,
personal attacks on me in a way more serious than name calling.
(because, it smacks of witch-hunting) (they naturally did this,
because they perceived that i attacked their computer language. This
is because, the computing language newsgroup tech geekers are utterly
ignorant of sociology, and combined with male power struggling
instict, have habored the thought about trolling, and some ethical
ideas about what one can or cannot say about other's computer
languages. Utterly bizarre.)
This doesn't happen to just me. It just a normal day in newsgroups.
Whoever, may it be professor, or eminent mathematician, professinoal
senior programers (as many are here), as long as he is a long time
newsgroup user, may have involved in verbal abuses given or taken.
(and each party are fully aware the other's social standings, but it
does'n matter. (e.g. in this very thread, a few started to gang up on
Jon Harrop, who is a author of a few functional language books)) It
is, the culture of newsgroups, so to speak. In a way, it is how people
WANT newsgroups to be the way it is. You knew it, i knew it, and we
should not deny it. If you are concerned about this state of affairs
of newsgroups, you need to rethink about it. Not the same old
instinctive good intentions. George motherfucking Bush has good
intentions and 50k to 300k Islamic civilians are dead. I'm sure you
are a kind man. Thousands of kind men existed in newsgroups before
you. They all have, at one time or another or more, given kind
advices, and contributed to what newsgroup is today.
I recommend a few articles. These articles, if tech geekrs all read
it, will help improve the state of affairs of newsgroups.
What Desires are Politically Important? by Bertrand Russell
http://xahlee.org/Periodic_dosage_dir/_p2/russell-lecture.html
Demonic Males. Apes and the Origins of Human Violence.
By Richard Wrangham and Dale Peterson
http://xahlee.org/p/demonic_males.html
Nice meeting you.
Xah
x@xahlee.org
? http://xahlee.org/
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