Re: assoc / dissoc consistency, maps and vectors
You also assume keys are comparable or that 'conj order' is retained, which
is often not true. Consider following map:
(your-dissoc {2 1, :a 1, "foo" 1, 'bar 1} 2)
=>
Vectors are indexed and maps are associative. These two concepts share some
functionalities (assoc, get), but are otherwise very different.
JW
On Sat, Nov 2, 2013 at 11:12 PM, wrote:
>
>
> On Saturday, November 2, 2013 4:56:13 PM UTC-5, Jozef Wagner wrote:
>>
>> Problem is, when your proposed dissoc removes value from a vector, it
>> shifts all larger keys. So dissoc would not only remove value at index
>> position, but also change keys for pther values. And this is not what
>> dissoc should do
>>
>
>
> You're right. I'm not sure why this is suddenly clear without essentially
> any new information. :) I think I had the wrong conceptual impression of
> what assoc and dissoc should be, putting the emphasis on the generality of
> the collection types instead its specificity to the indicies.
>
> For my notion of assoc/dissoc to hold parity, it would have to work like
> this which seems undesirable:
>
>
> (def some-vector ['a 'b 'c 'd 'e])
> (def some-map {0 'a 1 'b 2 'c 3 'd 4 'e})
>
>
> (assoc some-vector 2 'x)
> ;=> [a b x d e]
> (dissoc some-vector 2) ;; theoretical
> ;=> [a b d e] ;; theoretical
>
> (assoc some-map 2 'x)
> ;=> {0 a, 1 b, 2 x, 3 d, 4 e}
> (dissoc some-map 2)
> ;=> {0 a, 1 b, 2 d, 3 e} ;; not good
>
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Re: assoc / dissoc consistency, maps and vectors
On Saturday, November 2, 2013 4:56:13 PM UTC-5, Jozef Wagner wrote:
>
> Problem is, when your proposed dissoc removes value from a vector, it
> shifts all larger keys. So dissoc would not only remove value at index
> position, but also change keys for pther values. And this is not what
> dissoc should do
>
You're right. I'm not sure why this is suddenly clear without essentially
any new information. :) I think I had the wrong conceptual impression of
what assoc and dissoc should be, putting the emphasis on the generality of
the collection types instead its specificity to the indicies.
For my notion of assoc/dissoc to hold parity, it would have to work like
this which seems undesirable:
(def some-vector ['a 'b 'c 'd 'e])
(def some-map {0 'a 1 'b 2 'c 3 'd 4 'e})
(assoc some-vector 2 'x)
;=> [a b x d e]
(dissoc some-vector 2) ;; theoretical
;=> [a b d e] ;; theoretical
(assoc some-map 2 'x)
;=> {0 a, 1 b, 2 x, 3 d, 4 e}
(dissoc some-map 2)
;=> {0 a, 1 b, 2 d, 3 e} ;; not good
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Re: assoc / dissoc consistency, maps and vectors
Problem is, when your proposed dissoc removes value from a vector, it shifts all larger keys. So dissoc would not only remove value at index position, but also change keys for pther values. And this is not what dissoc should do user=> (map-indexed vector [:a :b :c :d]) ([0 :a] [1 :b] [2 :c] [3 :d]) user=> (dissoc [:a :b :c :d] 1) ;; your proposal [:a :c :d] user=> (map-indexed vector [:a :c :d]) ([0 :a] [1 :c] [2 :d]) JW On Saturday, November 2, 2013 8:40:37 PM UTC+1, vra...@gmail.com wrote: > > > > On Saturday, November 2, 2013 2:38:57 PM UTC-5, vra...@gmail.com wrote: >> >> (assoc some-vector 2 'x) >> ;=> [a b x d e] >> (dissoc some-vector 3) ;; proposed >> ;=> [a b d e] >> > > Typo: > > (assoc some-vector 2 'x) > ;=> [a b x d e] > (dissoc some-vector 2) ;; proposed > ;=> [a b d e] > -- -- 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 --- You received this message because you are subscribed to the Google Groups "Clojure" group. To unsubscribe from this group and stop receiving emails from it, send an email to clojure+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/groups/opt_out.
Re: assoc / dissoc consistency, maps and vectors
On Saturday, November 2, 2013 2:38:57 PM UTC-5, vra...@gmail.com wrote: > > (assoc some-vector 2 'x) > ;=> [a b x d e] > (dissoc some-vector 3) ;; proposed > ;=> [a b d e] > Typo: (assoc some-vector 2 'x) ;=> [a b x d e] (dissoc some-vector 2) ;; proposed ;=> [a b d e] -- -- 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 --- You received this message because you are subscribed to the Google Groups "Clojure" group. To unsubscribe from this group and stop receiving emails from it, send an email to clojure+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/groups/opt_out.
Re: assoc / dissoc consistency, maps and vectors
On Saturday, November 2, 2013 2:20:40 PM UTC-5, Ben wrote:
>
> So then (get (dissoc some-vector i) i) would be equivalent to (get
> some-vector (inc i))?
>
(def some-vector ['a 'b 'c 'd 'e])
(assoc some-vector 0 'x)
;=> [x b c d e]
(dissoc some-vector 0) ;; proposed
;=> [b c d e]
(assoc some-vector 1 'x)
;=> [a x c d e]
(dissoc some-vector 1) ;; proposed
;=> [a c d e]
(assoc some-vector 2 'x)
;=> [a b x d e]
(dissoc some-vector 3) ;; proposed
;=> [a b d e]
(def some-map {0 'a 1 'b 2 'c 3 'd 4 'e})
(assoc some-map 0 'x)
;=> {0 x, 1 b, 2 c, 3 d, 4 e}
(dissoc some-map 0)
;=> {1 b, 2 c, 3 d, 4 e}
(assoc some-map 1 'x)
;=> {0 a, 1 x, 2 c, 3 d, 4 e}
(dissoc some-map 1)
;=> {0 a, 2 c, 3 d, 4 e}
(assoc some-map 2 'x)
;=> {0 a, 1 b, 2 x, 3 d, 4 e}
(dissoc some-map 2)
;=> {0 a, 1 b, 3 d, 4 e}
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Re: assoc / dissoc consistency, maps and vectors
On Sat, Nov 2, 2013 at 11:51 AM, wrote: > > > > (dissoc ['a 'b 'c] 1) > > ;=> ['a 'c] > So then (get (dissoc some-vector i) i) would be equivalent to (get some-vector (inc i))? -- Ben Wolfson "Human kind has used its intelligence to vary the flavour of drinks, which may be sweet, aromatic, fermented or spirit-based. ... Family and social life also offer numerous other occasions to consume drinks for pleasure." [Larousse, "Drink" entry] -- -- 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 --- You received this message because you are subscribed to the Google Groups "Clojure" group. To unsubscribe from this group and stop receiving emails from it, send an email to clojure+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/groups/opt_out.
Re: assoc / dissoc consistency, maps and vectors
On Saturday, November 2, 2013 1:16:42 PM UTC-5, Andy Fingerhut wrote: > > What would you expect the return value of (dissoc ['a 'b 'c] 1) to be? > Hi Andy, Thanks for your interest! This is the "ideal" behavior I would expect from dissoc, for consistency with assoc: (assoc ['a 'b 'c] 1 'x) ;=> ['a 'x 'c] (dissoc ['a 'b 'c] 1) ;=> ['a 'c] (assoc-in [['a 'b] ['c 'd]] [1 1] 'x) ;=> [[a b] [c x]] (clojure.core.incubator/dissoc-in [['a 'b] ['c 'd]] [1 1]) ;=> [[a b] [c]] -- -- 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 --- You received this message because you are subscribed to the Google Groups "Clojure" group. To unsubscribe from this group and stop receiving emails from it, send an email to clojure+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/groups/opt_out.
Re: assoc / dissoc consistency, maps and vectors
What would you expect the return value of (dissoc ['a 'b 'c] 1) to be? On Sat, Nov 2, 2013 at 11:03 AM, wrote: > I realize `dissoc` isn't implemented to work on vectors for technical > reasons (such as explained on 1/13/11 here > https://groups.google.com/forum/#!msg/clojure/Lx9ysZ4ndfw/E52rVTvclMoJ ). > > "It'd be nice" if it did as I still get surprised by this on occasion, it > feels like an inconsistency when using Clojure such that I'd imagine it's a > general point of frustration for others as well. > > > (assoc [1 2 3] 1 'a) > ;=> [1 a 3] > > (dissoc ['a 'b 'c] 1) > ;=> ClassCastException clojure.lang.PersistentVector cannot be cast to > clojure.lang.IPersistentMap clojure.lang.RT.dissoc (RT.java:759) > > > (assoc-in [['a 'b] ['c 'd]] [1 1] 'x) > ;=> [[a b] [c x]] > > (clojure.core.incubator/dissoc-in [['a 'b] ['c 'd]] [1 1]) > ;=> ClassCastException clojure.lang.PersistentVector cannot be cast to > clojure.lang.IPersistentMap clojure.lang.RT.dissoc (RT.java:759) > > -- > -- > 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 > --- > You received this message because you are subscribed to the Google Groups > "Clojure" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to clojure+unsubscr...@googlegroups.com. > For more options, visit https://groups.google.com/groups/opt_out. > -- -- 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 --- You received this message because you are subscribed to the Google Groups "Clojure" group. To unsubscribe from this group and stop receiving emails from it, send an email to clojure+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/groups/opt_out.
assoc / dissoc consistency, maps and vectors
I realize `dissoc` isn't implemented to work on vectors for technical reasons (such as explained on 1/13/11 here https://groups.google.com/forum/#!msg/clojure/Lx9ysZ4ndfw/E52rVTvclMoJ ). "It'd be nice" if it did as I still get surprised by this on occasion, it feels like an inconsistency when using Clojure such that I'd imagine it's a general point of frustration for others as well. (assoc [1 2 3] 1 'a) ;=> [1 a 3] (dissoc ['a 'b 'c] 1) ;=> ClassCastException clojure.lang.PersistentVector cannot be cast to clojure.lang.IPersistentMap clojure.lang.RT.dissoc (RT.java:759) (assoc-in [['a 'b] ['c 'd]] [1 1] 'x) ;=> [[a b] [c x]] (clojure.core.incubator/dissoc-in [['a 'b] ['c 'd]] [1 1]) ;=> ClassCastException clojure.lang.PersistentVector cannot be cast to clojure.lang.IPersistentMap clojure.lang.RT.dissoc (RT.java:759) -- -- 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 --- You received this message because you are subscribed to the Google Groups "Clojure" group. To unsubscribe from this group and stop receiving emails from it, send an email to clojure+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/groups/opt_out.
