ok ok. . . .but yall made lists functions . .. so I could ask the same
question of
if foo(3): bar(3). if foo a function or a list? It looks like a function.
but it's a list, too. . . .because in clojure lists are functions . . . .but
only if they take one argument. I didn't start the confusion.
On Jan 13, 6:45 pm, e wrote:
> sure . . . I'm just impressed with how many things "just work", and this
> could be one more. Not enough args, but you know what I wanted it to mean.
> There's no ambiguity.
This is a bad idea. It just adds confusion with no real benefit.
Reading the code would be
sure . . . I'm just impressed with how many things "just work", and this
could be one more. Not enough args, but you know what I wanted it to mean.
There's no ambiguity.
On Tue, Jan 13, 2009 at 2:07 AM, Timothy Pratley
wrote:
>
>
>
> On Jan 13, 5:57 pm, e wrote:
> > Instead of that being an err
On Jan 13, 5:57 pm, e wrote:
> Instead of that being an error, why not overload the vector function so that
> no args calls the version that returns the list. That seems like a good
> idea! I wonder if people will object.
Actually in your case that would not work, because l2 can also be nil.
Instead of that being an error, why not overload the vector function so that
no args calls the version that returns the list. That seems like a good
idea! I wonder if people will object.
On Tue, Jan 13, 2009 at 1:23 AM, e wrote:
> seriously? Wow! Interesting.
>
>
> On Tue, Jan 13, 2009 at 12
seriously? Wow! Interesting.
On Tue, Jan 13, 2009 at 12:53 AM, Timothy Pratley
wrote:
>
> >(if (l2)
>
> The problem is on this line. (l2) is a function call.
> Replace with (if l2
> and it works fine :)
>
> java.lang.IllegalArgumentException: Wrong number of args passed to:
> LazilyPersiste
> (if (l2)
The problem is on this line. (l2) is a function call.
Replace with (if l2
and it works fine :)
java.lang.IllegalArgumentException: Wrong number of args passed to:
LazilyPersistentVector (NO_SOURCE_FILE:0)
The error message bears a little explaining:
vectors are functions,
user=> (
my unsafe version works now, thanks to a LOT of help.
(defn msort [toSort]
(with-local-vars [my-list (for [x toSort] [x])]
(while (rest @my-list)
(let [[l1 l2 & my-list-rest] @my-list]
(var-set my-list (conj my-list-rest (listmerge l1 l2)))
)) (first @my-list)))
now I'm try
> by the way, Tim, I've seen NB before as comments in J. What's it stand for?
An abbreviation for nota bene, a Latin expression meaning "note
well".
> I need to learn how to run closure code as a script then.
http://en.wikibooks.org/wiki/Clojure_Programming/Getting_Started
first section shows
o #2 . . . and I totally lost site of what I was doing with l1 and
l2 ! they were already lists because my-list was a list of lists. I new
that when I started, like on Friday.
On Mon, Jan 12, 2009 at 10:39 PM, e wrote:
> o! all the stuff from listmerge ended up in my-list d
by the way, Tim, I've seen NB before as comments in J. What's it stand for?
On Mon, Jan 12, 2009 at 10:39 PM, e wrote:
> o! all the stuff from listmerge ended up in my-list directly. so
> then when listmerge was called on these elements it rightly complained!
> Awesome. Lots of good
o! all the stuff from listmerge ended up in my-list directly. so
then when listmerge was called on these elements it rightly complained!
Awesome. Lots of good lessons coming out of this.
I need to learn how to run closure code as a script then. I seem to
remember something about this w
> I just want to get this out of my system, but I'm getting some class cast
> exception and no useful line number.
In situations like these I find that looking at the entire stack trace
provides clues. The REPL by default does not print the entire stack
though I'm sure there is a way to achieve t
i forgot about the wiki. why is this maintained in a totally different page
from clojure.org? I should be looking at these examples:
http://en.wikibooks.org/wiki/Clojure_Programming/Examples/API_Examples
On Mon, Jan 12, 2009 at 9:15 PM, e wrote:
> I give up.I don't know what's wrong and I
I give up.I don't know what's wrong and I don't want to just punt and go
on to a totally different implementation. Can while loops have more that
one statement in the body? Maybe it's something dumb.
I'm not turning my back on what people say about loop/recur or functional
programming. I'm
On Jan 12, 5:24 am, e wrote:
> It's funny, whenever I tried to be all safe like this and take the time to
> make stuff safe in C++, coworkers would say, "we are grown-ups. At some
> point you gotta stop being a paranoid programmer.
Given that software bugs are a very common occurrence, I'd say
a few fixes. still not there yet.
(defn elisort [toSort]
(with-local-vars [my-list (for [x toSort] [x])]
(while (rest (var-get my-list))
(let [[l1 l2 & my-list2] (var-get my-list)]
(var-set my-list (concat my-list2 (listmerge [l1] [l2] (first
(var-get my-list)
On Mon, Ja
I'm not planning on programming like this, but just to try to finish this up
. . . .it's still not working. I get an odd error when I actually try to
sort something that iSeq doesn't work on integers. I have no idea where to
still the (first my-list) at the end so it returns, too. No need to rep
looks like an awesome book. will check it out more. thanks.
On Mon, Jan 12, 2009 at 1:06 AM, Josip Gracin wrote:
>
> On Sun, Jan 11, 2009 at 10:33 PM, e wrote:
> > thanks for your patience. I think I'm starting to get it.
> > Interesting discussion on tail recursion.
>
> Just to add $0.02...
> is the @ symbol the same as a var-get . . . or is that an atom.
@ is a reader macro that translates to (deref ) which works on vars,
atoms, refs, agents.
and yes is interchangeable with var-get.
> Your sentence about atoms was very compound. I'm not sure if you said that
>you
> used an atom
I'm sure you are right. I'm going to have to be good at making these
arguments with my coworkers (or find somewhere else to work, maybe? :) ) so
I appreciate the depth people are going to.
One of my next bouts of confusion is going to come from trying to figure out
what's already done. Like I r
On Sun, Jan 11, 2009 at 10:33 PM, e wrote:
> thanks for your patience. I think I'm starting to get it.
> Interesting discussion on tail recursion.
Just to add $0.02... The fact that 'recur' in Clojure is actually used
to implement iterative and not recursive processes is easier to
understand af
My point was that it is not a missing capability,
Say you want to accumulate some changes, in this case sum odd numbers:
In C++ someone might write this:
int x = 0;
for (int i=0; i<100; i++) {
if ( i%2==1 ) x+=i;
}
However in Clojure you have a choice:
(reduce + (range 1 100 2))
Or you could
Bear with the trials and tribulations (of grokking
functional/clojure). It takes a few weeks of trying things out,
absorbing the documentation and group archives, watching the group
posts and then suddenly there are one or two "aha" moments and then
the flood gates open! When you've crossed the t
is the @ symbol the same as a var-get . . . or is that and atom. Your
sentence about atoms was very compound. I'm not sure if you said that you
used an atom but you didn't have to . . . .or you didn't use an atom because
it wasnt necessary . . . . or you did use an atom because it was necessary
w
here's a good explanation:
http://groups.google.com/group/clojure/browse_thread/thread/3c22b35f079e0de6/95fc0b334ab77c1f
I wasn't thinking about closures since I've only recently even learned what
they are. I actually don't know if it will ever occur to me to use them,
but it sounds like they are
> thread should own the memory that's created. Each thread should have
> its own asynchronous stack to push local variables onto that no one
> else is allowed to see.
Just for the record, Clojure does support local variable that behave
exactly as you would expect them:
(with-local-vars [x 3]
(
thanks for your patience. I think I'm starting to get it.
Interesting discussion on tail recursion. Add a lot of depth to what
Rich was talking about. Really smart work-around!
On Jan 11, 2:50 pm, James Reeves wrote:
> On Jan 11, 7:19 pm, e wrote:
>
> > oh. I missed the "recur my-list" in y
On Jan 11, 7:19 pm, e wrote:
> oh. I missed the "recur my-list" in your answer. So we still don't
> have an iterative solution. Recursion should never be necessary. I
> agree that it simplifies things sometimes and you can use it when you
> are stuck. . . . .but no need to push a whole stack
On Jan 11, 7:09 pm, e wrote:
> if it has tighter scope, then I don't understand why you don't have an
> infinite loop. The nested my-list that you redefined should have
> nothing to do with the my-list that you are doing the 'rest' check
> on.
That's what the loop/recur form does. Again, loop/r
oh. I missed the "recur my-list" in your answer. So we still don't
have an iterative solution. Recursion should never be necessary. I
agree that it simplifies things sometimes and you can use it when you
are stuck. . . . .but no need to push a whole stack frame for such a
simple problem, I wou
if it has tighter scope, then I don't understand why you don't have an
infinite loop. The nested my-list that you redefined should have
nothing to do with the my-list that you are doing the 'rest' check
on. (rest my-list) should always be non-nil because the inner let is
operating on a different
On Jan 11, 6:19 pm, e wrote:
> This gets to my question perfectly. Why is your code "my-list
> (rest (rest my-list)) " legal?
Because you're not actually changing anything.
In theory, the let form can be derived from anonymous functions. So
(let [x y] ...) is the same as ((fn [x] ...) y).
Or,
>
> i see that "my-list (rest (rest my-list))" is in a let section. That
> seems like the scope would mean we are talking about a different my-
> list.
>
Yes, it is a new my-list with a smaller scope. I didn't search for the
expression (rest (rest my-list)) before my earlier response.
--~--~---
>
>
> This gets to my question perfectly. Why is your code "my-list
> (rest (rest my-list)) " legal?
> I wouldn't have even thought to try that because, in essence, you are
> changing my-list. I mean, I know how persistence works. You are just
> reassigning what you think of as the start of my-l
i see that "my-list (rest (rest my-list))" is in a let section. That
seems like the scope would mean we are talking about a different my-
list.
On Jan 11, 1:19 pm, e wrote:
> that's awesome, and I hope it helps others, too. Thanks for starting
> with python.
>
> This gets to my question perfe
that's awesome, and I hope it helps others, too. Thanks for starting
with python.
This gets to my question perfectly. Why is your code "my-list
(rest (rest my-list)) " legal?
I wouldn't have even thought to try that because, in essence, you are
changing my-list. I mean, I know how persistence
Thinking functionally is hard when you're used to programming
imperatively. So instead of leaping straight into Clojure, lets stick
with Python for the time being.
So let's take your Python code:
def msort(someList):
myList = [[x] for x in someList]
while len(myList) > 1:
l1 = myList.pop
On Sun, Jan 11, 2009 at 10:50 AM, e wrote:
>
> refs seem silly in this context! Now I REALLY have to get my head
> wrapped around clojure. sooo I only have one thread, but I have
> to do a dosync? Why can this whole function just work in a thread
> agnostic way? It's a local variable! If
refs seem silly in this context! Now I REALLY have to get my head
wrapped around clojure. sooo I only have one thread, but I have
to do a dosync? Why can this whole function just work in a thread
agnostic way? It's a local variable! If a thread calls it, then a
thread should own the memor
I'm trying to follow. Can you explain in pseudo code? That's
impressive that it follows the classic approach on persistent data
structures . . .. from what I can tell. You successively divide the
list in halves of halves of halves. Then the lists of size 1 are
merged together as the stack unwi
great. I wondered about that, too! thanks.
On Jan 11, 7:27 am, James Reeves wrote:
> On Jan 11, 6:32 am, "Nick Vogel" wrote:
>
> > Ok, first of all, here's how I translated that python code:
>
> > (defn msort [myList]
> > (if (> (count myList) 1)
> > (let [l1 (first myList) l2 (second m
that looks interesting, except it is missing the part where you take
the original list and make it into a list of lists using list
comprehension. That works in python and clojure for me ... "the so
far so good part". If the recur were to do that repeatedly, the
algorithm would get messed up. St
thanks for all the help. just to answer the last question, 'sorted'
should have taken on the new def before getting returned. that return
happens after the def is complete. Will check out refs. I think
that's what I need to understand.
On Jan 11, 1:27 am, "Eric Lavigne" wrote:
> > I have no
Hi,
I'm just learning Clojure too, so I don't have much to add to what
everyone else has said, but here's my crack at a full implenentation
of merge-sort in Clojure. I'm sure that there is plenty of room for
improvement (especially wrt. the merge function) but in case it's
helpful, here it is:
On Jan 11, 6:32 am, "Nick Vogel" wrote:
> Ok, first of all, here's how I translated that python code:
>
> (defn msort [myList]
> (if (> (count myList) 1)
> (let [l1 (first myList) l2 (second myList)]
> (recur (concat (drop 2 myList) (my-merge l1 l2
> (first myList)))
I'd chan
By the way just to clarify, the use of recur is iterative, it's just
written in clojure in its recursive form.
On Jan 11, 1:32 am, "Nick Vogel" wrote:
> Ok, first of all, here's how I translated that python code:
>
> (defn msort [myList]
> (if (> (count myList) 1)
> (let [l1 (first myList)
Ok, first of all, here's how I translated that python code:
(defn msort [myList]
(if (> (count myList) 1)
(let [l1 (first myList) l2 (second myList)]
(recur (concat (drop 2 myList) (my-merge l1 l2
(first myList)))
The main thing that might need explaining is the recur, which b
>
>
> I have no idea how to iteratively mess with it since everything is
> persistent. Ok, like, say it's a list of lists and I am going to be
> merging the lists, like Tarjan's mergesort from some book from
> college.
>
Sorting is done much more easily with recursion than with iteration.
However
I'm just trying to understand basic stuff.
say I have a local list called "myList" (assigned using 'let' . . .
should I have used something else?) Who cares what's in it. Maybe I
set it up from a list comprehension from some input to my function.
I have no idea how to iteratively mess with it s
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