On Jul 14, 5:12 pm, Stuart Sierra wrote:
> On Jul 14, 3:01 pm, bgray wrote:
>
> > Ok, so *if* this is intended behavior, what have people been doing to
> > bind variables dependant on other bindings? I can't be the first to
> > run into this.
>
> Just nest multiple binding forms:
> (binding [
this is how you do it:
user=> (def a 0)
#'user/a
user=> (binding [a 1] (map #(+ % a) (range 5)))
(0 1 2 3 4)
user=> (binding [a 1] (let [a a] (map #(+ a %) (range 5
(1 2 3 4 5)
user=>
you capture the dynamic scope in the lexical scope so the closure can
close over it.
dunno how applicable t
It almost seems like what you want is for lazy data structures to
close over the dynamic vars that have been modified from their root
bindings at the time the lazy data structure is created. Seems like
coming up with well-defined semantics for this would be an interesting
research problem, and if
Hi,
Am 14.07.2009 um 21:01 schrieb bgray:
Ok, so *if* this is intended behavior, what have people been doing to
bind variables dependant on other bindings? I can't be the first to
run into this.
I haven't run into this, but there are two obvious approaches:
(let [new-a (compute n e w a)]
On Jul 14, 3:01 pm, bgray wrote:
> Ok, so *if* this is intended behavior, what have people been doing to
> bind variables dependant on other bindings? I can't be the first to
> run into this.
Just nest multiple binding forms:
(binding [a ...]
(binding [b ...]
...))
Not pretty, but it do
closures capture lexical scope, binding creates dynamic scope. lexical
scope is where a closure is defined, dynamic is when it is called.
because filter is lazy, the closure is called outside the dynamic
scope created by binding
On Jul 14, 1:07 pm, Aaron Cohen wrote:
> I'm a little unclear on w
I'm a little unclear on why this happens still.
#(= % a) is a closure, correct? My understanding is that this should
capture the environment when it is defined. Why does "the environment" not
include the current bindings?
-- Aaron
On Tue, Jul 14, 2009 at 4:03 PM, Mark Engelberg wrote:
>
> On
On Tue, Jul 14, 2009 at 12:40 PM, Jarkko Oranen wrote:
> This is a common gotcha. It's actually a laziness issue: the seq
> produced by filter is realised only after it exits the binding scope,
> thus producing '(1). You need to use "doall" to force the seq if you
> want the binding to apply.
Yea
That makes sense. Thanks for the quick help!
On Jul 14, 2:40 pm, Chouser wrote:
> On Tue, Jul 14, 2009 at 3:04 PM, bgray wrote:
>
> > I'm not sure if this is a binding issue or not.
>
> > user=> (def a 1)
> > #'user/a
> > user=> (binding [
On Jul 14, 10:04 pm, bgray wrote:
> I'm not sure if this is a binding issue or not.
>
> user=> (def a 1)
> #'user/a
> user=> (binding [a 3] (filter #(= % a) '(1 2 3)))
> (1)
> user=>
>
> In this case, I was expecting a list with 3 in it.
This
On Tue, Jul 14, 2009 at 3:04 PM, bgray wrote:
>
> I'm not sure if this is a binding issue or not.
>
> user=> (def a 1)
> #'user/a
> user=> (binding [a 3] (filter #(= % a) '(1 2 3)))
> (1)
> user=>
>
> In this case, I was expecting a li
I'm not sure if this is a binding issue or not.
user=> (def a 1)
#'user/a
user=> (binding [a 3] (filter #(= % a) '(1 2 3)))
(1)
user=>
In this case, I was expecting a list with 3 in it.
Thanks,
Brandon
--~--~-~--~~~---~--~~
You received
Ok, so *if* this is intended behavior, what have people been doing to
bind variables dependant on other bindings? I can't be the first to
run into this.
Thanks!
Brandon
On Jul 12, 12:05 am, Tom Faulhaber wrote:
> Looking at the clojure docs, it doesn't appear to be defined whether
> binding is
Looking at the clojure docs, it doesn't appear to be defined whether
binding is a parallel (all vars are computed based on the initial
state) or sequential (vars are computed using the new values for vars
used in the same binding vector). A quick test shows that it appears
to be parallel:
(bindin
Is this behavior expected from binding?
user=> (def a nil)
#'user/a
user=> (def b nil)
#'user/b
user=> (binding [a 1 b (+ a 1)] a)
java.lang.NullPointerException (NO_SOURCE_FILE:0)
user=> (binding [a 1 b (+ a 1)] b)
java.lang.NullPointerException (NO_SOURCE_FILE:0)
user=> (let [a 1 b (+ a 1)] a)
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