From b77115850fa485a2e7e56f065e97f03f8f0cb50a Mon Sep 17 00:00:00 2001
From: Vincent Cantin <vincent.cantin@le-moulin-studio.com>
Date: Mon, 21 Jan 2019 23:18:19 +0800
Subject: [PATCH 1/2] Rewrote `reitit.core/path-conflicting-routes` using
 transducers.

---
 modules/reitit-core/src/reitit/core.cljc | 20 ++++++++++----------
 1 file changed, 10 insertions(+), 10 deletions(-)

diff --git a/modules/reitit-core/src/reitit/core.cljc b/modules/reitit-core/src/reitit/core.cljc
index a2f090d0..e88b15bc 100644
--- a/modules/reitit-core/src/reitit/core.cljc
+++ b/modules/reitit-core/src/reitit/core.cljc
@@ -65,17 +65,17 @@
   (cond->> (->> (walk raw-routes opts) (map-data merge-data))
            coerce (into [] (keep #(coerce % opts)))))
 
-;; This whole function might be more efficient and easier to understand with transducers.
 (defn path-conflicting-routes [routes]
-  (some->>
-    (loop [[r & rest] routes, acc {}]
-      (if (seq rest)
-        (let [conflicting (set (keep #(if (impl/conflicting-routes? r %) %) rest))]
-          (recur rest (update acc r (fnil (comp set concat) #{}) conflicting)))
-        acc))
-    (filter (comp seq second))
-    (seq)
-    (into {})))
+  (let [conflicting-routes
+        (into {}
+              (comp (map-indexed (fn [index route]
+                                   [route (into #{}
+                                                (filter #(impl/conflicting-routes? route %))
+                                                (subvec routes (inc index)))]))
+                    (filter (comp seq second)))
+              routes)]
+    (when (seq conflicting-routes)
+      conflicting-routes)))
 
 (defn conflicting-paths [conflicts]
   (->> (for [[p pc] conflicts]

From fdf249a959981c916d7f53a624c2214ed4fa4583 Mon Sep 17 00:00:00 2001
From: Vincent Cantin <vincent.cantin@le-moulin-studio.com>
Date: Tue, 22 Jan 2019 08:22:48 +0800
Subject: [PATCH 2/2] Apply a change suggested by Miikka Koskinen.

---
 modules/reitit-core/src/reitit/core.cljc | 18 ++++++++----------
 1 file changed, 8 insertions(+), 10 deletions(-)

diff --git a/modules/reitit-core/src/reitit/core.cljc b/modules/reitit-core/src/reitit/core.cljc
index e88b15bc..b905915b 100644
--- a/modules/reitit-core/src/reitit/core.cljc
+++ b/modules/reitit-core/src/reitit/core.cljc
@@ -66,16 +66,14 @@
            coerce (into [] (keep #(coerce % opts)))))
 
 (defn path-conflicting-routes [routes]
-  (let [conflicting-routes
-        (into {}
-              (comp (map-indexed (fn [index route]
-                                   [route (into #{}
-                                                (filter #(impl/conflicting-routes? route %))
-                                                (subvec routes (inc index)))]))
-                    (filter (comp seq second)))
-              routes)]
-    (when (seq conflicting-routes)
-      conflicting-routes)))
+  (-> (into {}
+            (comp (map-indexed (fn [index route]
+                                 [route (into #{}
+                                              (filter #(impl/conflicting-routes? route %))
+                                              (subvec routes (inc index)))]))
+                  (filter (comp seq second)))
+            routes)
+      (not-empty)))
 
 (defn conflicting-paths [conflicts]
   (->> (for [[p pc] conflicts]