Re: Transient HashMaps with not more than 8 elements?
On Sat, May 29, 2010 at 08:52:59PM -0700, ataggart wrote:
Yup, you need to use the transient functions, e.g., assoc!, just as
you would the persistent functions. This is nice since you can write
your code in the persistent style, then if you need to make some
performance tweaks, simply add some exclamation points; the structure
of the code remains the same.
As for why you see what you're seeing, the assoc! does generally
mutate the passed in map, thus you see some map entries. The rub is
that assoc! is smart enough to choose the right implementation for the
size; for small maps (0-8 entries) an array-map is used (and the {}
literal is also an array-map). Once you assoc! the 9th element, the
function instead returns a hashmap, thus no longer mutating the
instance referenced by thm.
Ah, yes:
user (loop [thm (transient {}),
i 0]
(if (= 10 i)
(persistent! thm)
(recur (assoc! thm i i)
(inc i
{0 0, 1 1, 2 2, 3 3, 4 4, 5 5, 6 6, 7 7, 8 8, 9 9}
So, a fundamental misconception of mine then ;)
Thanks!
Daniel
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Transient HashMaps with not more than 8 elements?
Hi,
recently I discovered the following behaviour of transient hash-maps
which seems a bit odd to me:
user (def thm (transient {}))
#'user/thm
user (dotimes [i 10]
(assoc! thm i i))
nil
user (count thm)
8
user (persistent! thm)
{0 0, 1 1, 2 2, 3 3, 4 4, 5 5, 6 6, 7 7}
The same happens if i goes up to 100, 1000, ... Is this a bug or is
this a fundamental misconception of mine?
Daniel
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Re: ClassNotFoundException with def
On Sun, Jun 28, 2009 at 01:25:15PM -0700, hoeck wrote: [...] Tried it, and had the same results. Somehow defining a class object as a root value triggers some mechanism to load it with the root classloader instead of the clojure one. However, putting /home/me on the classpath using -cp works. Thank you, erik! Daniel --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups Clojure group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en -~--~~~~--~~--~--~---
