Well, maybe I shouldn't bash MIT-scheme unintentionally :-). I bet some people use it for serious stuff, and I have no bad experiences with it.
On Thu, Apr 24, 2014 at 11:33 AM, Gary Trakhman <gary.trakh...@gmail.com>wrote: > MIT-lisp is more for teaching than industrial use.. > > We also have hash-maps, vectors, sets, queues, conj works with all of > them, leaving the details up to the collection. > > Cons always adds to the front. Conj only adds to the back for certain > collections (vector, queue). > > You could work around it by reversing, consing, then reversing again, or > just use vectors and conj if you're always working on the tail. > > > On Thu, Apr 24, 2014 at 11:27 AM, Jiacai Liu <jiacai2...@gmail.com> wrote: > >> Oh,Thank you for answer. >> But if I just want to insert a element to list,and meantime want to >> insert in the back.How should I do? >> Another question: why clojure need both cons and conj? In mit-lisp cons >> just do all things. >> >> >> On Thursday, April 24, 2014 11:12:49 PM UTC+8, Gary Trakhman wrote: >> >>> Conj is polymorphic on its first argument. If you pass it a vector, >>> it'll add to the back, if a list, the front. The collection is responsible >>> for deciding the most efficient way to add an element. >>> >>> Cons always adds to the front, creating a linked-list node pointing to >>> the rest. Also, cons takes the sequence as the second argument. >>> >>> >>> On Thu, Apr 24, 2014 at 11:10 AM, Jiacai Liu <jiaca...@gmail.com> wrote: >>> >>>> hi everyone: >>>> I use Clojure to solve SICP 2.22 >>>> <http://www.billthelizard.com/2011/01/sicp-221-223-mapping-over-lists.html> >>>> . >>>> The problem is to rewrite a map fn in a iterative way，here it want to >>>> get the square of each element in a list >>>> Method 1: >>>> (defn square-list [items] >>>> (defn iter [things answer] >>>> (if (empty? things) >>>> answer >>>> (iter >>>> (rest things) >>>> (cons (square (first things)) answer)))) >>>> (iter items nil)) >>>> This method just return opposite result. >>>> (square-list (range 1 10)) >>>> ;===>(81 64 49 36 25 16 9 4 1) >>>> >>>> I think all I need is to swap the position of (square (first >>>> things))andanswer,then >>>> I can get the right order >>>> I write fn below: >>>> Method 2 >>>> (defn square-list [items] >>>> (defn iter [things answer] >>>> (if (empty? things) >>>> answer >>>> (iter >>>> (rest things) >>>> (conj answer (square (first things)))))) >>>> (iter items nil)) >>>> However, it still return opposite order. >>>> Did I misuse cons and conj or I ignore something? >>>> >>>> >>>> -- >>>> You received this message because you are subscribed to the Google >>>> Groups "Clojure" group. >>>> To post to this group, send email to clo...@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+u...@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+u...@googlegroups.com. >>>> >>>> For more options, visit https://groups.google.com/d/optout. >>>> >>> >>> -- >> 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/d/optout. >> > > -- 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/d/optout.
