In clojure, how can I select and return a subset of a collection












0















If I have a collection like this



{{:A "a" :B "b"} {:A "a" :B "Goal" } {:A "a" :B "Goal"}}


how do I make a function so it returns only the parts where :B "Goal"? Meaning only:



{{:A "a" :B "Goal" } {:A "a" :B "Goal"}}





collections clojure







share|improve this question























  • curly brackets are maps in Clojure and require an even number of members (key and value pairs) they can be of any type : keyword, string, number.. your collection above will be better represented as a vector [,,,] or a list'(,,,)

    – manandearth
    Nov 21 '18 at 17:35
















0















If I have a collection like this



{{:A "a" :B "b"} {:A "a" :B "Goal" } {:A "a" :B "Goal"}}


how do I make a function so it returns only the parts where :B "Goal"? Meaning only:



{{:A "a" :B "Goal" } {:A "a" :B "Goal"}}





collections clojure







share|improve this question























  • curly brackets are maps in Clojure and require an even number of members (key and value pairs) they can be of any type : keyword, string, number.. your collection above will be better represented as a vector [,,,] or a list'(,,,)

    – manandearth
    Nov 21 '18 at 17:35














0












0








0








If I have a collection like this



{{:A "a" :B "b"} {:A "a" :B "Goal" } {:A "a" :B "Goal"}}


how do I make a function so it returns only the parts where :B "Goal"? Meaning only:



{{:A "a" :B "Goal" } {:A "a" :B "Goal"}}





collections clojure







share|improve this question














If I have a collection like this



{{:A "a" :B "b"} {:A "a" :B "Goal" } {:A "a" :B "Goal"}}


how do I make a function so it returns only the parts where :B "Goal"? Meaning only:



{{:A "a" :B "Goal" } {:A "a" :B "Goal"}}





collections clojure




collections clojure






share|improve this question













share|improve this question











share|improve this question




share|improve this question










asked Nov 20 '18 at 23:36









John SlaineJohn Slaine

799




799













  • curly brackets are maps in Clojure and require an even number of members (key and value pairs) they can be of any type : keyword, string, number.. your collection above will be better represented as a vector [,,,] or a list'(,,,)

    – manandearth
    Nov 21 '18 at 17:35



















  • curly brackets are maps in Clojure and require an even number of members (key and value pairs) they can be of any type : keyword, string, number.. your collection above will be better represented as a vector [,,,] or a list'(,,,)

    – manandearth
    Nov 21 '18 at 17:35

















curly brackets are maps in Clojure and require an even number of members (key and value pairs) they can be of any type : keyword, string, number.. your collection above will be better represented as a vector [,,,] or a list'(,,,)

– manandearth
Nov 21 '18 at 17:35





curly brackets are maps in Clojure and require an even number of members (key and value pairs) they can be of any type : keyword, string, number.. your collection above will be better represented as a vector [,,,] or a list'(,,,)

– manandearth
Nov 21 '18 at 17:35












1 Answer
1






active

oldest

votes


















6














I fixed your data to make it a vector of 3 maps.



(def data [{:A "a" :B "b"}

           {:A "a" :B "Goal"}

           {:A "a" :B "Goal"}])



(defn b-goal?

  [item]

  (= (:B item) "Goal") )



(filter b-goal? data) => ({:A "a", :B "Goal"} {:A "a", :B "Goal"})



Be sure also to check out:




  • The Clojure CheatSheet

  • Clojure for the Brave and True


As well as books like




  • Living Clojure

  • Getting Clojure






share|improve this answer

























    Your Answer






    StackExchange.ifUsing("editor", function () {
    StackExchange.using("externalEditor", function () {
    StackExchange.using("snippets", function () {
    StackExchange.snippets.init();
    });
    });
    }, "code-snippets");

    StackExchange.ready(function() {
    var channelOptions = {
    tags: "".split(" "),
    id: "1"
    };
    initTagRenderer("".split(" "), "".split(" "), channelOptions);

    StackExchange.using("externalEditor", function() {
    // Have to fire editor after snippets, if snippets enabled
    if (StackExchange.settings.snippets.snippetsEnabled) {
    StackExchange.using("snippets", function() {
    createEditor();
    });
    }
    else {
    createEditor();
    }
    });

    function createEditor() {
    StackExchange.prepareEditor({
    heartbeatType: 'answer',
    autoActivateHeartbeat: false,
    convertImagesToLinks: true,
    noModals: true,
    showLowRepImageUploadWarning: true,
    reputationToPostImages: 10,
    bindNavPrevention: true,
    postfix: "",
    imageUploader: {
    brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
    contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
    allowUrls: true
    },
    onDemand: true,
    discardSelector: ".discard-answer"
    ,immediatelyShowMarkdownHelp:true
    });


    }
    });














    draft saved

    draft discarded


















    StackExchange.ready(
    function () {
    StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fstackoverflow.com%2fquestions%2f53403229%2fin-clojure-how-can-i-select-and-return-a-subset-of-a-collection%23new-answer', 'question_page');
    }
    );

    Post as a guest















    Required, but never shown

























    1 Answer
    1






    active

    oldest

    votes








    1 Answer
    1






    active

    oldest

    votes









    active

    oldest

    votes






    active

    oldest

    votes









    6














    I fixed your data to make it a vector of 3 maps.



    (def data [{:A "a" :B "b"}
    
           {:A "a" :B "Goal"}
    
           {:A "a" :B "Goal"}])
    

    
(defn b-goal?
    
  [item]
    
  (= (:B item) "Goal") )
    

    
(filter b-goal? data) => ({:A "a", :B "Goal"} {:A "a", :B "Goal"})



    Be sure also to check out:




    • The Clojure CheatSheet

    • Clojure for the Brave and True


    As well as books like




    • Living Clojure

    • Getting Clojure






    share|improve this answer






























      6














      I fixed your data to make it a vector of 3 maps.



      (def data [{:A "a" :B "b"}
      
           {:A "a" :B "Goal"}
      
           {:A "a" :B "Goal"}])
      

      
(defn b-goal?
      
  [item]
      
  (= (:B item) "Goal") )
      

      
(filter b-goal? data) => ({:A "a", :B "Goal"} {:A "a", :B "Goal"})



      Be sure also to check out:




      • The Clojure CheatSheet

      • Clojure for the Brave and True


      As well as books like




      • Living Clojure

      • Getting Clojure






      share|improve this answer




























        6












        6








        6







        I fixed your data to make it a vector of 3 maps.



        (def data [{:A "a" :B "b"}
        
           {:A "a" :B "Goal"}
        
           {:A "a" :B "Goal"}])
        

        
(defn b-goal?
        
  [item]
        
  (= (:B item) "Goal") )
        

        
(filter b-goal? data) => ({:A "a", :B "Goal"} {:A "a", :B "Goal"})



        Be sure also to check out:




        • The Clojure CheatSheet

        • Clojure for the Brave and True


        As well as books like




        • Living Clojure

        • Getting Clojure






        share|improve this answer















        I fixed your data to make it a vector of 3 maps.



        (def data [{:A "a" :B "b"}
        
           {:A "a" :B "Goal"}
        
           {:A "a" :B "Goal"}])
        

        
(defn b-goal?
        
  [item]
        
  (= (:B item) "Goal") )
        

        
(filter b-goal? data) => ({:A "a", :B "Goal"} {:A "a", :B "Goal"})



        Be sure also to check out:




        • The Clojure CheatSheet

        • Clojure for the Brave and True


        As well as books like




        • Living Clojure

        • Getting Clojure







        share|improve this answer














        share|improve this answer



        share|improve this answer








        edited Nov 21 '18 at 1:43

























        answered Nov 20 '18 at 23:49









        Alan ThompsonAlan Thompson

        14k22533




        14k22533
































            draft saved

            draft discarded




















































            Thanks for contributing an answer to Stack Overflow!


            • Please be sure to answer the question. Provide details and share your research!

            But avoid …



            • Asking for help, clarification, or responding to other answers.

            • Making statements based on opinion; back them up with references or personal experience.


            To learn more, see our tips on writing great answers.




            draft saved


            draft discarded














            StackExchange.ready(
            function () {
            StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fstackoverflow.com%2fquestions%2f53403229%2fin-clojure-how-can-i-select-and-return-a-subset-of-a-collection%23new-answer', 'question_page');
            }
            );

            Post as a guest















            Required, but never shown





















































            Required, but never shown














            Required, but never shown












            Required, but never shown







            Required, but never shown

































            Required, but never shown














            Required, but never shown












            Required, but never shown







            Required, but never shown







            -

            這個網誌中的熱門文章

            Tangent Lines Diagram Along Smooth Curve

            圖片
            7 1 I am trying to replicate a diagram and have a minimal example. I don't know how to add additional tangents between the specified points and preserve smoothness. documentclass{article} usepackage{tikz} usetikzlibrary{calc,intersections} begin{document} begin{tikzpicture} % Axes draw [->, name path=x] (-1,0) -- (11,0) node [right] {$x$}; draw [->] (0,-1) -- (0,6) node [above] {$y$}; % Origin node at (0,0) [below left] {$0$}; % Points coordinate (start) at (1,-0.8); coordinate (c1) at (3,3); coordinate (c2) at (5.5,1.5); coordinate (c3) at (8,4); coordinate (end) at (10.5,-0.8); % show the points foreach n in {start,c1,c2,c3,end} fill [black] (n) circle (2pt) node [below] {}; % join the coordinates draw [thick,name path=curve] (start) to[out=70,in=180] (c1) to[out=0,in=180]
            閱讀完整內容

            Yusuf al-Mu'taman ibn Hud

            圖片
            Main article: Taifa of Zaragoza Al-Mu'taman Ruler of Zaragoza Reign 1081–1085 Predecessor Ahmad al-Muqtadir Successor Al-Mustain II Born Zaragoza Died 1085 Full name Yusuf ibn Ahmad al-Mu'taman ibn Hūd House Banu Hud Yusuf ibn Ahmad al-Mu'taman ibn Hūd (Arabic: المؤتمن بالله يوسف إبن أحمد إبن هود ‎, al-Mutaman bi l-Lah , died c. 1085) was the third king of the Banu Hud dynasty who ruled over the Taifa of Zaragoza from 1081 to 1085. Yusuf al-Mutaman reigned during the height of power of Muslim Zaragoza , following the thriving period of his father Ahmad al-Muqtadir. He continued his father's efforts and created around him a court of intellectuals, living in the beautiful palace of Aljafería, nicknamed as "the palace of joy". Al-Mu'taman was also a scholarly king and a patron of science, philosophy and arts. As an example of a wise king, he knew astrology, philosophy, and especially mathematics, a discipline in which
            閱讀完整內容

            Zucchini

            圖片
            This article is about the vegetable. For other uses, see Zucchini (disambiguation). Zucchini (courgette) A striped and a uniform color zucchini Genus Cucurbita Species Cucurbita pepo Origin 19th century northern Italy The zucchini ( / z uː ˈ k iː n i / , American English) or courgette ( / k ʊər ˈ ʒ ɛ t / , British English) is a summer squash which can reach nearly 1 metre (100 cm; 39 in) in length, but is usually harvested when still immature at about 15 to 25 cm (6 to 10 in). [1] A zucchini is a thin-skinned cultivar of what in Britain and Ireland is referred to as a marrow. [2] [3] In South Africa, a zucchini is known as a baby marrow. Along with certain other squashes and pumpkins, the zucchini belongs to the species Cucurbita pepo . It can be dark or light green. A related hybrid, the golden zucchini, is a deep yellow or orange color. [4] In a culinary context, the zucchini is treated as a vegetable; it is usually cooked and presented as a savory dish o
            閱讀完整內容