Re: Opposite function to cons, but in terms of construction, not destruction.

2011-12-14 Thread Alan Malloy
On Dec 14, 2:22 am, Alan Malloy wrote: > On Dec 14, 1:18 am, Cedric Greevey wrote: > > > > > > > > > > > On Wed, Dec 14, 2011 at 3:12 AM, Alan Malloy wrote: > > > On Dec 13, 8:37 pm, Cedric Greevey wrote: > > >> On Tue, Dec 13, 2011 at 11:25 PM, Alan Malloy wrote: > > >> > On Dec 13, 7:56 pm,

Re: Opposite function to cons, but in terms of construction, not destruction.

2011-12-14 Thread Alan Malloy
On Dec 14, 1:18 am, Cedric Greevey wrote: > On Wed, Dec 14, 2011 at 3:12 AM, Alan Malloy wrote: > > On Dec 13, 8:37 pm, Cedric Greevey wrote: > >> On Tue, Dec 13, 2011 at 11:25 PM, Alan Malloy wrote: > >> > On Dec 13, 7:56 pm, Stephen Compall wrote: > >> >> On Tue, 2011-12-13 at 16:28 -0800, A

Re: Opposite function to cons, but in terms of construction, not destruction.

2011-12-14 Thread Cedric Greevey
On Wed, Dec 14, 2011 at 3:12 AM, Alan Malloy wrote: > On Dec 13, 8:37 pm, Cedric Greevey wrote: >> On Tue, Dec 13, 2011 at 11:25 PM, Alan Malloy wrote: >> > On Dec 13, 7:56 pm, Stephen Compall wrote: >> >> On Tue, 2011-12-13 at 16:28 -0800, Alan Malloy wrote: >> >> > As you can see, only as man

Re: Opposite function to cons, but in terms of construction, not destruction.

2011-12-14 Thread Alan Malloy
On Dec 13, 8:37 pm, Cedric Greevey wrote: > On Tue, Dec 13, 2011 at 11:25 PM, Alan Malloy wrote: > > On Dec 13, 7:56 pm, Stephen Compall wrote: > >> On Tue, 2011-12-13 at 16:28 -0800, Alan Malloy wrote: > >> > As you can see, only as many elements are realized as are needed to > >> > satisfy the

Re: Opposite function to cons, but in terms of construction, not destruction.

2011-12-13 Thread Cedric Greevey
On Tue, Dec 13, 2011 at 11:25 PM, Alan Malloy wrote: > On Dec 13, 7:56 pm, Stephen Compall wrote: >> On Tue, 2011-12-13 at 16:28 -0800, Alan Malloy wrote: >> > As you can see, only as many elements are realized as are needed to >> > satisfy the user's request. >> >> Yes, in the expression (conr (

Re: Opposite function to cons, but in terms of construction, not destruction.

2011-12-13 Thread Alan Malloy
On Dec 13, 7:56 pm, Stephen Compall wrote: > On Tue, 2011-12-13 at 16:28 -0800, Alan Malloy wrote: > > As you can see, only as many elements are realized as are needed to > > satisfy the user's request. > > Yes, in the expression (conr (conr (conr '( 1 2 3) 4) 6) 7), all the > lazy-seqs implied by

Re: Opposite function to cons, but in terms of construction, not destruction.

2011-12-13 Thread Stephen Compall
On Tue, 2011-12-13 at 16:28 -0800, Alan Malloy wrote: > As you can see, only as many elements are realized as are needed to > satisfy the user's request. Yes, in the expression (conr (conr (conr '( 1 2 3) 4) 6) 7), all the lazy-seqs implied by the conr calls must be forced immediately to yield (1

Re: Opposite function to cons, but in terms of construction, not destruction.

2011-12-13 Thread Alan Malloy
On Dec 13, 3:05 pm, Stephen Compall wrote: > On Mon, 2011-12-12 at 10:53 -0800, Michael Jaaka wrote: > > (defn conr[ col item ] > >    (lazy-seq > >            (if (seq col) > >                    (cons (first col) (conr (rest col) item)) > >                    (list item > > > And now stick w

Re: Opposite function to cons, but in terms of construction, not destruction.

2011-12-13 Thread Stephen Compall
On Mon, 2011-12-12 at 10:53 -0800, Michael Jaaka wrote: > (defn conr[ col item ] > (lazy-seq > (if (seq col) > (cons (first col) (conr (rest col) item)) > (list item > > And now stick with it. > All works as desired: > > (conr (c

Re: Opposite function to cons, but in terms of construction, not destruction.

2011-12-12 Thread Michael Jaaka
Thanks to all for responses. I just wanted to use that in higher-order composition in mind, not to construct any data structures. I have tweaked a bit the function: (defn conr[ col item ] (lazy-seq (if (seq col) (cons (first col) (conr (rest col) ite

Re: Opposite function to cons, but in terms of construction, not destruction.

2011-12-11 Thread Marco Abis
Hi, total newbie here but what about conj? (conj (conj (conj [ 1 2 3] 4) 6) 7) would return [1 2 3 4 6 7] -- Marco Abis -- 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 p

Re: Opposite function to cons, but in terms of construction, not destruction.

2011-12-10 Thread Andy Fingerhut
I forgot to mention, if you want a Clojure persistent data structure that is efficient (O(1) or O(log n)) for all of these operations: + adding to/removing from beginning + adding to/removing from end + concatenating + splitting into two sequences, at any specified item in the middle look at fing

Re: Opposite function to cons, but in terms of construction, not destruction.

2011-12-10 Thread Tamreen Khan
Conj (http://clojuredocs.org/clojure_core/clojure.core/conj) does what you need for vectors. It's behavior depends on the type of collection passed, so if you did: (conj '(1 2 3) 4) you would end up with '(4 1 2 3). For vectors it appends to the end of the list, for lists the beginning. On Sat,

Re: Opposite function to cons, but in terms of construction, not destruction.

2011-12-10 Thread Andy Fingerhut
conj adds an element to a data structure in a place most efficient for the particular type of data structure. For lists, this is at the beginning. For vectors, it is at the end: user=> (conj (conj (conj '(1 2 3) 4) 6) 7) (7 6 4 1 2 3) user=> (conj (conj (conj [1 2 3] 4) 6) 7) [1 2 3 4 6 7] If yo

Opposite function to cons, but in terms of construction, not destruction.

2011-12-10 Thread Michael Jaaka
Is there something like: (defn snoc[ col item ] (lazy-seq (if (seq col) (let[ [f & r] col ] (if (seq r) (cons f (snoc r item)) (cons f [i