On Fri, Oct 30, 2009 at 9:36 PM, Josh Daghlian wrote:
>
> Although I suppose this isn't too surprising:
>
> user> (second y)
> --> ConcurrentModificationException
Eeeuw. Guess it uses an Iterator to generate the elements for the lazy seq.
For ArrayList, walking it by index would avoid this. For
On Fri, Oct 30, 2009 at 9:31 PM, Josh Daghlian wrote:
> During the Boston Lisp Users meeting last November (?) I asked Rich
> about whether seq's on mutable java.util.Collections were really
> immutable if the underlying object (the Collection) was mutable. He
> emphatically said that no, the seq
Although I suppose this isn't too surprising:
user> (second y)
--> ConcurrentModificationException
--josh
On Oct 30, 9:31 pm, Josh Daghlian wrote:
> During the Boston Lisp Users meeting last November (?) I asked Rich
> about whether seq's on mutable java.util.Collections were really
> immutabl
During the Boston Lisp Users meeting last November (?) I asked Rich
about whether seq's on mutable java.util.Collections were really
immutable if the underlying object (the Collection) was mutable. He
emphatically said that no, the seq is still immutable, and that it
caches values as it sees them.
On Fri, Oct 30, 2009 at 12:40 PM, John Harrop wrote:
> (defn lazy-array-seq
> ([arr]
> (lazy-array-seq arr 0))
> ([arr from-idx]
> (lazy-array-seq arr 0 (count arr)))
> ([arr from-idx end-idx]
> (if-not (= from-idx end-idx)
> (lazy-seq (aget arr from-idx) (lazy-array-seq a
When someone knowingly dips into arrays, though, aren't doing so because
they require java's semantics? For speed, interop, or whatever?
We want to champion functional programming, but on the other hand we want to
preserve the smooth java-interop use-cases. Not an easy balancing act, I
suppose.
user=> (def x (int-array 3))
#'user/x
user=> x
[0, 0, 0]
user=> (def y (seq x))
#'user/y
user=> (first y)
0
user=> (aset x 1 3)
3
user=> x
[0, 3, 0]
user=> (second y)
3
user=> (aset x 0 2)
2
user=> x
[2, 3, 0]
user=> (first y)
2
Here, (first y) returned first 0, then 2 without y being rebound in b
