Scherrer, Chad wrote:
Maybe my point wasn't clear. Of course this idea of comparing lazy
evaluation to Unix pipes is very old (long before July 2004, I'm sure).
The point I'm making is that there is an old idea that may be underused.
It is, and only because (.) is defined all wrong!
The unix
On Wed, Nov 23, 2005 at 11:17:25AM +0100, Udo Stenzel wrote:
infixl 2 \|
(\|) = flip (.) -- though I'm using ()
The unix pipe becomes (filter (foo `isPrefixOf`) \| sort \| nub) or
something, which is rather neat, and (#) is used to call member
functions, as in
Why not use Control.Arrow. ?
On Wed, 23 Nov 2005, Udo Stenzel wrote:
Scherrer, Chad wrote:
Maybe my point wasn't clear. Of course this idea of comparing lazy
evaluation to Unix pipes is very old (long before July 2004, I'm sure).
The point I'm making is that there is an old idea that may be underused.
It is, and only
Henning Thielemann [EMAIL PROTECTED] writes:
Since
(a . b) x
a $ b x
a (b x)
are equivalent, do you also want to reverse function and
argument in order to match argument order of . and $ ?
That is
x (b . a)
x b $ a
(x b) a
?
I'm sorry, I'm not sure I understand your
On Wed, 23 Nov 2005, Scherrer, Chad wrote:
Henning Thielemann [EMAIL PROTECTED] writes:
Since
(a . b) x
a $ b x
a (b x)
are equivalent, do you also want to reverse function and
argument in order to match argument order of . and $ ?
That is
x (b . a)
x b $ a
(x b) a
?
I'm
Henning Thielemann [EMAIL PROTECTED] writes:
I want to say, that the order of symbols for ($), (.) and
function application is consistent. This is a fine thing. I
think that shall not be distroyed by giving ($) and (.)
reversed argument order.
I see. I like the argument order also,
Udo Stenzel [EMAIL PROTECTED] writes:
The unix pipe is actually function composition. Its argument
(standard
input) isn't explicitly mentioned
Then it seems Unix must overload the | operator. I typically use it to
do things like
grep . *.hs | wc
So I think of the types as being
grep .
On Wed, Nov 23, 2005 at 09:01:07AM -0800, Scherrer, Chad wrote:
So I think of the types as being
grep . *.hs :: String
wc :: String - Int -- ok, not really, but it shows the point better.
Every unix program has a standard input, even if it doesn't use it, so
I would rather give this type to
On Wed, 2005-11-23 at 08:55 -0800, Scherrer, Chad wrote:
. . .
I see. I like the argument order also, since it so nicely reflects
mathematical notation. But I do think there's a place for (flip ($)) and
(flip (.)). The problem is that the assignment of fixities is much more
subtle and
On Wed, 2005-11-23 at 17:47 +0100, Henning Thielemann wrote:
. . .
Why is there no () and why is (=) not the default? The order of 'do
{a;b;c}' is compatible with that of (). So we have the fundamental
conflict, that usually function application is from right to left, but
interpreting
On 23/11/05, Scherrer, Chad [EMAIL PROTECTED] wrote:
Bill Wood [EMAIL PROTECTED] writes:
Interesting note: in Richard Bird and Oege de Moor, _Algebra
of Programming_, pp. 2-3, the authors write
As a departure from tradition, we write f : A - B rather than
f : B - A to indicate
On Wed, 2005-11-23 at 21:21 -0500, Cale Gibbard wrote:
. . .
Hmm, which edition? My copy (5th ed.) uses the ordinary notation: f(x).
x f does perhaps make more sense, especially with the current
categorical view of functions, but there would have to be a really
hugely good reason to
Cale Gibbard:
x f does perhaps make more sense, especially with the current
categorical view of functions, but there would have to be a really
hugely good reason to change notation, as almost all current work puts
things the other way around.
Almost all?
Well, excluding the Smalltalkers,
On 24/11/05, [EMAIL PROTECTED]
[EMAIL PROTECTED] wrote:
Cale Gibbard:
x f does perhaps make more sense, especially with the current
categorical view of functions, but there would have to be a really
hugely good reason to change notation, as almost all current work puts
things the other
Albert Lai [EMAIL PROTECTED] writes:
I offer a simpler, more direct, and pre-existing correspondence
between a functional
programming construct and unix pipes:
Maybe my point wasn't clear. Of course this idea of comparing lazy
evaluation to Unix pipes is very old (long before July 2004, I'm
On Tue, Nov 22, 2005 at 02:09:40PM -0800, Scherrer, Chad wrote:
(\|) = flip ($) -- (#) seems to me too pretty for other purposes to use
it here.
infixl 0 \| -- Again, why can't this be negative or Fractional??
I have a ? operator that does the same thing. Next time I use it I'll
check if
I offer a simpler, more direct, and pre-existing correspondence
between a functional programming construct and unix pipes:
http://www.vex.net/~trebla/weblog/pointfree.html
Scherrer, Chad [EMAIL PROTECTED] writes:
I'm still trying to settle on a feel for good programming style in
Haskell.
I'm still trying to settle on a feel for good programming style in
Haskell. One thing I've been making some use of lately is
(\|) = flip ($)
infixl 0 \|
Then expressions like
f4 $ f3 $ f2 $ f1 $ x
become
x \|
f1 \|
f2 \|
f3 \|
f4
I've seen something like this on haWiki using (#), but I
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