huge speedup to if-path by having specialized implementation separate from cond-path

src/clj/com/rpl/specter.cljx

@@ -528,9 +528,21 @@
 
 (defpathedfn if-path
   "Like cond-path, but with if semantics."
-  ([cond-p if-path] (cond-path cond-p if-path))
-  ([cond-p if-path else-path]
-    (cond-path cond-p if-path nil else-path)))
+  ([cond-p then-path]
+    (fixed-pathed-nav [late-cond cond-p
+                       late-then then-path]
+      (select* [this structure next-fn]
+        (i/if-select structure next-fn late-cond late-then STOP))
+      (transform* [this structure next-fn]
+        (i/if-transform structure next-fn late-cond late-then STOP))))
+  ([cond-p then-path else-path]
+    (fixed-pathed-nav [late-cond cond-p
+                       late-then then-path
+                       late-else else-path]
+      (select* [this structure next-fn]
+        (i/if-select structure next-fn late-cond late-then late-else))
+      (transform* [this structure next-fn]
+        (i/if-transform structure next-fn late-cond late-then late-else)))))
 
 (defpathedfn multi-path
   "A path that branches on multiple paths. For updates,

src/clj/com/rpl/specter/impl.cljx

@@ -709,6 +709,20 @@
             res
             ))))))
 
+(defn if-select [structure next-fn late-cond late-then late-else]
+  (let [apath (if (empty? (compiled-select* late-cond structure))
+                late-else
+                late-then)]
+    (doall (mapcat next-fn (compiled-select* apath structure)))
+    ))
+
+(defn if-transform [structure next-fn late-cond late-then late-else]
+  (let [apath (if (empty? (compiled-select* late-cond structure))
+                late-else
+                late-then)]
+    (compiled-transform* apath next-fn structure)
+    ))
+
 (defn filter-select [afn structure next-fn]
   (if (afn structure)
     (next-fn structure)))