Hi there,
I can ask if something is an fn, like this: (fn? first)
How do I do it when first is a string?
Example:
(def mylist '( map, first, nofun))
This doesn't work, of course:
(map fn? mylist)
How can I transpose, e.g. first to something so that I can feed fn?
with it?
--
Hi,
On Sun, Apr 04, 2010 at 10:06:12AM +0200, Manfred Lotz wrote:
I can ask if something is an fn, like this: (fn? first)
How do I do it when first is a string?
Example:
(def mylist '( map, first, nofun))
This doesn't work, of course:
(map fn? mylist)
Of course it does. It
(map #(fn? (when-let [x (resolve (symbol %))] @x)) [map, first,
nofun]) should do the trick. But before you go ahead and do this,
make sure it's what you actually need.
-Per
On Sun, Apr 4, 2010 at 3:06 PM, Manfred Lotz manfred.l...@arcor.de wrote:
Hi there,
I can ask if something is an fn,
Hi,
I have a situation where:
1) I have a lot of 'values' that are both expensive to compute and quite
large (they aren't all going to fit into memory) and most of which will not be
needed (this time, but maybe later)
2) I may have a need to update several of them them (in a transaction)
This is with Clojure 1.1.0:
user= ( Float/NaN 1.0)
false
user= (= Float/NaN 1.0)
true
Both comparisons should yield false. It seems that (= x y) is
implemented by negating the result of ( y x), which is fine for
totally-ordered sets, but unfortunately IEEE 754 floating-point
numbers do not form
Interesting question. Here's something I whipped up in response:
http://gist.github.com/355456
I intentionally provide only lazy-alter and no lazy-ref-set. The
reason is that lazy-alter can be coded so that all the unwrapping and
rewrapping of delays can be abstracted away from the user-provided
On 2010-04-04, at 11:15 AM, Per Vognsen wrote:
Interesting question. Here's something I whipped up in response:
http://gist.github.com/355456
I intentionally provide only lazy-alter and no lazy-ref-set. The
reason is that lazy-alter can be coded so that all the unwrapping and
rewrapping
Hi Per,
On Sun, 4 Apr 2010 15:28:23 +0700
Per Vognsen per.vogn...@gmail.com wrote:
(map #(fn? (when-let [x (resolve (symbol %))] @x)) [map, first,
nofun]) should do the trick. But before you go ahead and do this,
make sure it's what you actually need.
-Per
Thanks a lot. That was
On 2010-04-04, at 11:15 AM, Per Vognsen wrote:
Interesting question. Here's something I whipped up in response:
http://gist.github.com/355456
I intentionally provide only lazy-alter and no lazy-ref-set. The
reason is that lazy-alter can be coded so that all the unwrapping and
rewrapping
I don't understand why you need to get rid of the delay once it has been
updated. Delays are cheap; why not just be consistent about having your
data be a ref of a delay? It will keep your code simpler, and that's well
worth it.
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Rich has said that he intentionally didn't want to provide a uniform
interface for setting and altering reference-like objects, and I agree
with him. It wouldn't be difficult to have to have a function that
calls send on agents, swap! on atoms, set! on vars and ref-set on
refs. But it would give
Hmm. A this point am not using javac at all, just Clojure. So (in
theory) I would expect to need a config setting on the clojure-maven-
plugin instead. I'll give it a spin though!
Stu
Hi,
On 01.04.2010, at 20:00, Stuart Halloway wrote:
(2) When I import the project, the package explorer
AFAIK, there's only one issue keeping the current master (and 1.1) from
running on Dalvik:
https://www.assembla.com/spaces/clojure/tickets/199-chunked-seqs-support--for--byte-code-can-t-be-converted-to-dex-for-dalvik
So clone the 1.1.x branch from Rich and revert commit 306ef6 and it may
just
Hello Clojure!
Is there any straight-forward way to randomly reorder a list?
ie:
(randomize-list (list 1 2 3 4))
- (3 2 1 4)
Regards,
Linus Ericsson
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There's a shuffle function in seq-utils:
user= (use 'clojure.contrib.seq-utils)
nil
user= (shuffle (list 1 2 3 4))
(3 4 1 2)
-Lee
On Apr 4, 2010, at 4:14 PM, Linus Ericsson wrote:
Hello Clojure!
Is there any straight-forward way to randomly reorder a list?
ie:
(randomize-list
The seq-utils library has a shuffle function that calls out to
java.util.Collections.
If you want to do it yourself, the easiest would be
(defn naive-shuffle [xs]
(let [v (vec xs)]
(- (count v) range lex-permutations rand-elt (map v
This uses the seq-utils and combinatorics libraries
Since we're having a shuffle-a-thon, here's a version I wrote that I kind of
like for its simplicity, even though it uses a recursive call that Clojure
apparently can't optimize. (FWIW I wrote a version that used loop/recur
instead, but it was actually slower for some reason):
(defn shuffle
(This is a follow up to my query last week, where upon I didn't fully
connect these dots)
According to:
http://clojure.org/reader
\ and \ are not in the valid list of sanctioned symbol characters.
According to:
http://richhickey.github.com/clojure/clojure.core-api.html
A quick test shows that it's about 3 times faster than my
knuth-shuffle. Here's a version using transients that is 2x faster but
still not quite as fast as yours:
(defn rand-range [m n]
(+ m (rand-int (- n m
(defn swap-entries! [x i j]
(assoc! x i (x j) j (x i)))
(defn knuth-shuffle
For those interested in clojure maven, I've just published
http://github.com/AntonyBlakey/polyglot-maven/tree/reflective-clojure-dsl ,
which is a clojure front-end for polyglot maven. It could do with more testing,
and documentation, but apart from dealing with namespaces and attributes in the
On my system, knuth-shuffle performs several times faster than Spector's
recursive functional shuffle on smallish lists, and the difference grows
even more dramatic as the list grows, which is what I'd expect (since
knuth-shuffle is O(n) and shuffle is O(n^2)).
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Wow, you're right. The partial laziness of his code was foiling my benchmark.
-Per
On Mon, Apr 5, 2010 at 11:05 AM, Mark Engelberg
mark.engelb...@gmail.com wrote:
On my system, knuth-shuffle performs several times faster than Spector's
recursive functional shuffle on smallish lists, and the
Ah -- maybe that foiled my timings too. I didn't expect it to be fast -- just
clear (at least to this Lisp programmer).
-Lee
On Apr 5, 2010, at 12:11 AM, Per Vognsen wrote:
Wow, you're right. The partial laziness of his code was foiling my benchmark.
-Per
On Mon, Apr 5, 2010 at 11:05
On Mon, Apr 5, 2010 at 11:33 AM, Lee Spector lspec...@hampshire.edu wrote:
Ah -- maybe that foiled my timings too. I didn't expect it to be fast -- just
clear (at least to this Lisp programmer).
Embrace recursion combinators! They are warm and fuzzy!
Here's a gist of the final cleaned up
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