June 2018 Update

Task/Read-a-configuration-file/Clojure/read-a-configuration-file.clj

@@ -1,2 +1,48 @@
-(let [cfg (read-string (slurp "config.edn"))]
-  (clojure.pprint/pprint cfg))
+(ns read-conf-file.core
+  (:require [clojure.java.io :as io]
+            [clojure.string :as str])
+  (:gen-class))
+
+(def conf-keys ["fullname"
+                "favouritefruit"
+                "needspeeling"
+                "seedsremoved"
+                "otherfamily"])
+
+(defn get-lines
+  "Read file returning vec of lines."
+  [file]
+  (try
+    (with-open [rdr (io/reader file)]
+      (into [] (line-seq rdr)))
+    (catch Exception e (.getMessage e))))
+
+(defn parse-line
+  "Parse passed line returning vec: token, vec of values."
+  [line]
+  (if-let [[_ k v] (re-matches #"(?i)^\s*([a-z]+)(?:\s+|=)?(.+)?$" line)]
+    (let [k (str/lower-case k)]
+      (if v
+        [k (str/split v #",\s*")]
+        [k [true]]))))
+
+(defn mk-conf
+  "Build configuration map from lines."
+  [lines]
+  (->> (map parse-line lines)
+       (filter (comp not nil?))
+       (reduce (fn
+                 [m [k v]]
+                 (assoc m k v)) {})))
+
+(defn output
+  [conf-keys conf]
+  (doseq [k conf-keys]
+    (let [v (get conf k)]
+      (if v
+        (println (format "%s = %s" k (str/join ", " v)))
+        (println (format "%s = %s" k "false"))))))
+
+(defn -main
+  [filename]
+  (output conf-keys (mk-conf (get-lines filename))))