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# rivaldi8/chapter10.clj

Last active Nov 2, 2018
Exercises from the book Clojure for the brave and true (http://www.braveclojure.com/)
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 ; This is free and unencumbered software released into the public domain. (ns chapter10.core (require [clojure.string :as str]) (:gen-class)) (defn print-exercise-result [exercise-function, number] (println (str "== Exercise " number " ==")) (println (str (exercise-function) "\n"))) (defn exercise1 [] (def atom-test (atom 0)) (swap! atom-test inc) (swap! atom-test inc) @atom-test) (defn download-quote [] (slurp "http://www.braveclojure.com/random-quote")) (defn add-word-counts [total-word-count text] (println "quote:\n" text) (doseq [word (str/split text #" ")] (swap! total-word-count (fn [current-state] (merge-with + current-state {word 1}))))) (defn create-quote-futures [quote-count total-word-count] (repeatedly quote-count #(future (add-word-counts total-word-count (download-quote))))) (defn wait-for-futures [futures] (dorun (map deref futures))) (defn quote-word-count [quote-count] (def total-word-count (atom {})) (wait-for-futures (create-quote-futures quote-count total-word-count)) @total-word-count) (defn exercise2 [] (quote-word-count 5)) (def MAX-HIT-POINTS 40) (def character1 (ref {:name "Guybrush" :hit-points 15 :inventory {:grog 35}})) (def character2 (ref {:name "Elaine" :hit-points MAX-HIT-POINTS :inventory {:healing-potion 100}})) (defn exercise3 [] (def character1-before @character1) (def character2-before @character2) (dosync (def needed-healing (- MAX-HIT-POINTS (:hit-points @character1))) (alter character1 update-in [:hit-points] + needed-healing) (alter character2 update-in [:inventory :healing-potion] - needed-healing)) (str "== Before ==\n" character1-before "\n" character2-before "\n" "== After ==\n" @character1 "\n" @character2)) (defn -main [& args] (print-exercise-result exercise1 1) (print-exercise-result exercise2 2) (print-exercise-result exercise3 3) (shutdown-agents))
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 ; This is free and unencumbered software released into the public domain. (ns mapset.core (:gen-class)) (defn mapset [function collection] (loop [remaining-elements collection new-collection #{}] (if (empty? remaining-elements) new-collection (let [[head & tail] remaining-elements] (recur tail (into new-collection [(function head)])))))) (defn -main [& args] (println (mapset #(* 10 %) [1 2 3])))
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 ; This is free and unencumbered software released into the public domain. (ns radial-symmetrize.core (:gen-class)) (def asym-hobbit-body-parts [{:name "head" :size 3} {:name "left-eye" :size 1} {:name "left-ear" :size 1} {:name "mouth" :size 1} {:name "nose" :size 1} {:name "neck" :size 2} {:name "left-shoulder" :size 3} {:name "left-upper-arm" :size 3} {:name "chest" :size 10} {:name "back" :size 10} {:name "left-forearm" :size 3} {:name "abdomen" :size 6} {:name "left-kidney" :size 1} {:name "left-hand" :size 2} {:name "left-knee" :size 2} {:name "left-thigh" :size 4} {:name "left-lower-leg" :size 3} {:name "left-achilles" :size 1} {:name "left-foot" :size 2}]) (defn build-middle-part [part] {:name (clojure.string/replace (:name part) #"^left-" "middle-") :size (:size part)}) (defn build-side-part [part side number] {:name (clojure.string/replace (:name part) #"^left-" (str side number "-")) :size (:size part)}) (defn radial-symmetrize [part] (if (clojure.string/starts-with? (:name part) "left-") [(build-side-part part "left" 1) (build-side-part part "left" 2) (build-middle-part part) (build-side-part part "right" 1) (build-side-part part "right" 2)] [part])) (defn radial-symmetrize-body-parts [asym-parts] (reduce (fn [final-parts part] (into final-parts (radial-symmetrize part))) [] asym-parts)) (defn -main [& args] (println (radial-symmetrize-body-parts asym-hobbit-body-parts)))
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 ; This is free and unencumbered software released into the public domain. (ns fwpd.core) (def filename "suspects.csv") (def vamp-keys [:name :glitter-index]) (defn str->int [str] (Integer. str)) (def conversions {:name identity :glitter-index str->int}) (defn convert [vamp-key value] ((get conversions vamp-key) value)) (defn is-name-present? [record] (contains? record :name)) (defn is-glitter-index-present? [record] (contains? record :glitter-index)) (def validations {:name is-name-present? :glitter-index is-glitter-index-present?}) (defn validate [validate-functions record] (and ((:name validate-functions) record) ((:glitter-index validate-functions) record))) (defn mapify [rows] (map (fn [unmapped-row] (reduce (fn [row-map [vamp-key value]] (assoc row-map vamp-key (convert vamp-key value))) {} (map vector vamp-keys unmapped-row))) rows)) (defn glitter-filter [minimum-glitter records] (filter #(>= (:glitter-index %) minimum-glitter) records)) (defn append [new-suspect suspects] (if (validate validations new-suspect) (cons new-suspect suspects) suspects)) (defn parse "Convert a CSV into rows of columns" [string] (map #(clojure.string/split % #",") (clojure.string/split string #"\n"))) (defn map->csv [vamp-map] (clojure.string/join "," [(:name vamp-map) (:glitter-index vamp-map)])) (defn map-list->csv [map-list] (clojure.string/join "\n" (map map->csv map-list))) (defn -main [& args] (println "== Vampires ==") (def suspects (mapify (parse (slurp filename)))) (def vamps (map :name (glitter-filter 3 suspects))) (doall (map #(println %) vamps)) (println "\n== Vampires (v2) ==") (def new-suspect {:name "Jander Klander" :glitter-index 4}) (def suspects-v2 (append new-suspect suspects)) (def vamps-v2 (map :name (glitter-filter 3 suspects-v2))) (doall (map #(println %) vamps-v2)) (println "\n== Vampires (v3) ==") (def another-new-suspect {:name "Hinkli Mincli"}) (def suspects-v3 (append another-new-suspect suspects-v2)) (def vamps-v3 (map :name (glitter-filter 3 suspects-v3))) (doall (map #(println %) vamps-v3)) (println "*** Wrong suspect record 'Hinkli Mincli' should not appear. ***") (println "\n== suspects (v3) CSV ==") (println (map-list->csv suspects-v3)))
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 ; This is free and unencumbered software released into the public domain. (ns chapter5.core (:gen-class)) (defn print-exercise-result [exercise-function, number] (println (str "== Exercise " number " ==")) (println (str (exercise-function) "\n"))) (defn exercise1 [] (def character {:name "Smooches McCutes" :attributes {:intelligence 10 :strength 4 :dexterity 5}}) (defn attr [attribute-getter] ((comp attribute-getter :attributes) character)) (str "Intelligence: " (attr :intelligence))) (defn exercise2 [] (defn comp-alexm [first-function & rest-functions] (if rest-functions (fn [param] (first-function ((apply comp-alexm rest-functions) param))) #(first-function %))) ((comp-alexm #(* % 2) #(+ % 1)) 3)) (defn exercise3 [] (defn assoc-in-alexm [m [k & ks] v] (if ks (assoc m k (assoc-in-alexm {} ks v))) (assoc m k v)) (assoc-in-alexm {:foo "bar"} [:cookie :monster :vocals] "Finntroll")) (defn mightyfier [mightee mighter] (str mightee mighter)) (defn exercise4 [] (def m {:cookie {:monster {:vocals "Finntroll"}}}) (update-in m [:cookie :monster :vocals] mightyfier " the mighty!")) (defn exercise5 [] (def m {:cookie {:monster {:vocals "Finntroll"}}}) (defn update-in-alexm [m [k & ks] f & args] (if ks (assoc m k (apply update-in-alexm (get m k) ks f args)) (apply update m k f args))) (update-in-alexm m [:cookie :monster :vocals] mightyfier " the mighty!")) (defn -main [& args] (print-exercise-result exercise1 1) (print-exercise-result exercise2 2) (print-exercise-result exercise3 3) (print-exercise-result exercise4 4) (print-exercise-result exercise5 5))
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 ; This is free and unencumbered software released into the public domain. (ns chapter7.core (:gen-class)) (defn print-exercise-result [exercise-function, number] (println (str "== Exercise " number " ==")) (println (str (exercise-function) "\n"))) (defn exercise1 [] ;; TODO: use read-string. Where? (eval (list 'println "Àlex" "Alien 2"))) (defn exercise2 [] ;; TODO: implement operator precedence (defn precedence [operator] (if (or (= operator "+") (= operator "-")) 0 ;; * or / 1)) (defn infix [expression] (println "infix:" expression) (if (= (count expression) 3) (list (second expression) (first expression) (last expression)) (let [operand (first expression) operator (second expression) rest-expression (nthrest expression 2)] (if (> (precedence operator) 0) (list operator operand (infix rest-expression)) (list operator (infix rest-expression) operand))))) (infix (reverse (list 1 "+" 3 "*" 4 "-" 5)))) (defn -main [& args] (print-exercise-result exercise1 1) (print-exercise-result exercise2 2))
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 ; This is free and unencumbered software released into the public domain. (ns chapter8.core (:gen-class)) (defn print-exercise-result [exercise-function, number] (println (str "== Exercise " number " ==")) (println (str (exercise-function) "\n"))) (defmacro when-valid [data valid? & to-do] `(when (~valid? ~data) ~@to-do)) (defn data-valid? [data] (> data 0)) (defn exercise1 [] (def some-data 1) (when-valid some-data data-valid? (println "The data is valid!") (println "Done!"))) (defmacro or-alexm ([] true) ([x] x) ([x & rest-expressions] `(let [or# ~x] (if or# true (or-alexm ~@rest-expressions))))) (defn exercise2 [] (if (and (or-alexm false true) (or-alexm true false) (or-alexm false true false) (not (or-alexm false false false))) "OK" "FAIL")) (def character {:name "Smooches McCutes" :attributes {:intelligence 10 :strength 4 :dexterity 5}}) (defmacro defattrs [& func-attr-pairs] (loop [pairs func-attr-pairs funcs '()] (if (empty? pairs) funcs (let [function (first pairs) attribute (second pairs) rest-pairs (nthrest pairs 2)] (recur rest-pairs (conj funcs `(def ~function (comp ~attribute :attributes)))))))) (defn exercise3 [] (defattrs c-int :intelligence c-str :strength) (str (:name character) " intelligence: " (c-int character) "\n" (:name character) " strenght: " (c-str character))) (defn -main [& args] (print-exercise-result exercise1 1) (print-exercise-result exercise2 2) (print-exercise-result exercise3 3))
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 ; This is free and unencumbered software released into the public domain. (ns chapter9.core (:require [clojure.string :as str]) (:gen-class)) (defn print-exercise-result [exercise-function, number] (println (str "== Exercise " number " ==")) (println (str (exercise-function) "\n"))) (defn search-yahoo [query] (slurp (str "https://es.search.yahoo.com/search?q=" query))) (defn search-wikipedia [query] (slurp (str "https://es.wikipedia.org/wiki/Especial:Buscar?search=" query))) (defn search [query] (let [search-result (promise)] (future (deliver search-result (search-yahoo query))) (future (deliver search-result (search-wikipedia query))) @search-result)) (defn exercise1 [] (search "Enjuto")) (def search-engines { :yahoo "https://es.search.yahoo.com/search?q=" :wikipedia "https://es.wikipedia.org/wiki/Especial:Buscar?search="}) (defn search-in "Searches query in the search engine and returns the HTML page as an string" [query engine] (slurp (str (engine search-engines) query))) (defn search2 "Searches query in the list of search engines and returns the HTML page of the first search engine to respond as an string" [query engines] (let [search-result (promise)] (doseq [engine engines] (future (deliver search-result (search-in query engine)))) @search-result)) (defn exercise2 [] (search2 "Mojamuto" [:yahoo :wikipedia])) (def href-regex #"href=\"([^\"]*)\"") (defn get-search-result-urls "Queries the search engine and returns a list of URLs found in the results page." [query engine] (map second ; second gets the grup match with the URL (re-seq href-regex (search-in query engine)))) (defn search3 "Queries each search engine from engines and returns a map of (search engine, urls future) pairs. URL future are futures that when derefenced return a list of URLs found in the results page of the search engine." [query engines] (zipmap engines (map #(future (get-search-result-urls query %)) engines))) (defn print-links [links] (doseq [link links] (println " *" link))) (defn print-search-results [search-results-map] (doseq [keyval-pair search-results-map] (println "---" (key keyval-pair) "---\n") (print-links @(val keyval-pair))) "") (defn exercise3 [] (print-search-results (search3 "Enjuto" [:yahoo :wikipedia]))) (defn -main [& args] (print-exercise-result exercise1 1) (print-exercise-result exercise2 2) (print-exercise-result exercise3 3) (shutdown-agents))

### rivaldi8 commented Aug 3, 2016

If you see something wrong or that can be solved in a better way, please, add a comment :-)