Clean up ns and make code more idiomatic

src/loom/alg.clj

@@ -4,13 +4,13 @@ can use these functions."
       :author "Justin Kramer"}
   loom.alg
   (:require [loom.alg-generic :as gen]
-            [loom.flow :as flow])
-  (:require [loom.graph
+            [loom.flow :as flow]
+            [loom.graph
              :refer [add-nodes add-edges nodes edges successors weight predecessors
                      out-degree in-degree weighted? directed? graph transpose]
              :as graph]
-            [loom.alg-generic :refer [trace-path preds->span]])
-  (:require [clojure.data.priority-map :as pm]
+            [loom.alg-generic :refer [trace-path preds->span]]
+            [clojure.data.priority-map :as pm]
             [clojure.set :as clj.set]))
 
 ;;;
@@ -311,7 +311,7 @@ can use these functions."
       false
       (let [dist (if (weighted? g)
                    (weight g)
-                   (fn [u v] (if (graph/has-edge? g u v) 1 nil)))]
+                   (fn [u v] (when (graph/has-edge? g u v) 1)))]
         (reduce (fn [acc node]
                   (assoc acc node (gen/dijkstra-span (successors g) dist node)))
                 {}
@@ -434,7 +434,7 @@ can use these functions."
                   ;; TODO: could be better
                   (if (some #(and (coloring %) (= (coloring v) (coloring %)))
                             nbrs)
-                    nil ;not bipartite
+                    nil ; graph is not bipartite
                     (let [nbrs (remove coloring nbrs)]
                       (recur (into coloring (for [nbr nbrs] [nbr color]))
                              (into (pop queue) nbrs))))))))]
@@ -474,7 +474,7 @@ can use these functions."
                     successors
                     (concat successors
                             (graph/predecessors g node)))]
-    (set (filter (complement nil?)
+    (set (remove nil?
                  (map #(get coloring %)
                       neighbors)))))
 
@@ -621,7 +621,7 @@ can use these functions."
                  curr-dist ((second (peek q)) 2)
                  ;; update path
                  explored (assoc explored curr-node ((second (peek q)) 1))
-                 nbrs (filter (complement explored) (successors g curr-node))
+                 nbrs (remove explored (successors g curr-node))
                  ;; we do this for following reasons
                  ;; a. avoiding duplicate heuristics computation
                  ;; b. duplicate entries for nodes, which needs to be removed later

src/loom/alg_generic.clj

@@ -83,7 +83,7 @@
                     seen)))))
       (when-let [parent (peek stack)]
         (recur successors parent (peek nbrstack)
-               (pop stack) (pop nbrstack) (conj seen start)))))] 
+               (pop stack) (pop nbrstack) (conj seen start)))))]
     (when-not (seen start)
       (step successors start (successors start) [] [] (conj seen start)))))
 
@@ -133,9 +133,8 @@
   once for each direction."
   [successors start & {:keys [seen return-seen] :or {seen #{}}}]
   (if (seen start)
-    (if return-seen
-      [nil seen]
-      nil)
+    (when return-seen
+      [nil seen])
     (loop [start start
           nbrs (successors start)
           stack []

src/loom/flow.clj

@@ -1,7 +1,7 @@
 (ns ^{:doc "Algorithms for solving network flow"
       :author "Robert Lachlan"}
   loom.flow
-  (:require [loom.alg-generic :as gen :only [bf-path]]))
+  (:require [loom.alg-generic :as gen :refer [bf-path]]))
 
 
 (defn residual-capacity
@@ -74,7 +74,7 @@
   [successors predecessors capacity flow s t]
   (gen/bf-path
    (fn [vertex]
-     (distinct (filter #(> (residual-capacity capacity flow vertex %) 0)
+     (distinct (filter #(pos? (residual-capacity capacity flow vertex %))
                        (concat (successors vertex) (predecessors vertex)))))
    s t))
 

src/loom/graph.clj

@@ -45,7 +45,7 @@ on adjacency lists."
 (extend-type clojure.lang.IPersistentVector
   Edge
   (src [edge] (get edge 0))
-  (dest [edge] (get edge 1)))  
+  (dest [edge] (get edge 1)))
 
 ; Default implementation for maps
 (extend-type clojure.lang.IPersistentMap
@@ -108,7 +108,7 @@ on adjacency lists."
                  (contains? (get-in g [:adj n1]) n2))
     :out-degree (fn [g node]
                  (count (get-in g [:adj node])))
-    :out-edges (fn 
+    :out-edges (fn
                  ([g] (partial out-edges g))
                  ([g node] (for [n2 (successors g node)] [node n2])))}
 
@@ -144,7 +144,7 @@ on adjacency lists."
                    ([g node] (get-in g [:in node])))
    :in-degree (fn [g node]
                 (count (get-in g [:in node])))
-   :in-edges (fn 
+   :in-edges (fn
                ([g] (partial in-edges g))
                ([g node] (for [n2 (predecessors g node)] [n2 node])))})
 
@@ -430,7 +430,7 @@ on adjacency lists."
 (defn subgraph
   "Return a graph without all but the given nodes"
   [g ns]
-  (remove-nodes* g (filter (complement (set ns)) (nodes g))))
+  (remove-nodes* g (remove (set ns) (nodes g))))
 
 (defn add-path
   "Add a path of edges connecting the given nodes in order"

src/loom/io.clj

@@ -41,11 +41,11 @@
   (let [d? (directed? g)
         w? (weighted? g)
         a? (attr? g)
-        node-label (if node-label node-label
+        node-label (or node-label
                        (if a?
                          #(attr g % :label)
                          (constantly nil)))
-        edge-label (if edge-label edge-label
+        edge-label (or edge-label
                        (cond
                          a? #(if-let [a (attr g %1 %2 :label)]
                                a
@@ -115,12 +115,11 @@
     ;; There's an 'open' method in java.awt.Desktop but it hangs on Windows
     ;; using Clojure Box and turns the process into a GUI process on Max OS X.
     ;; Maybe it's ok for Linux?
-    (do
-      (condp = (os)
-        :mac (sh "open" (str f))
-        :win (sh "cmd" (str "/c start " (-> f .toURI .toURL str)))
-        :unix (sh "xdg-open" (str f)))
-      nil)))
+    (condp = (os)
+      :mac (sh "open" (str f))
+      :win (sh "cmd" (str "/c start " (-> f .toURI .toURL str)))
+      :unix (sh "xdg-open" (str f)))
+    nil))
 
 (defn- open-data
   "Write the given data (string or bytes) to a temporary file with the