refac(topological_sort): rm unneeded variables

Author: Damian Rouson

src/dag_s.f90

@@ -35,18 +35,13 @@ pure module function topological_sort(dag) result(order)
 
     block
       type(searched_and_ordered_t) searched_and_ordered
-      integer, allocatable :: discovered(:)
       integer v
 
-      allocate(discovered(0))
       searched_and_ordered = searched_and_ordered_t(s = [integer::], o = [integer::])
 
       do v = 1, size(dag%vertices)
-        if (.not. any(v == searched_and_ordered%s)) then
+        if (.not. any(v == searched_and_ordered%s)) &
           searched_and_ordered = depth_first_search(v, [integer::], searched_and_ordered%o)
-          discovered = [discovered, searched_and_ordered%s]
-          searched_and_ordered%s= discovered
-        end if
       end do
       order = searched_and_ordered%o
     end block
@@ -60,22 +55,21 @@ pure recursive function depth_first_search(v, d, o) result(hybrid)
 
       call assert(.not. any(v == d), "depth_first_search: cycle detected", intrinsic_array_t([v,d]))
 
-      block
-        integer, allocatable :: dependencies(:)
-        integer w
-
-        hybrid = searched_and_ordered_t(s = [integer::], o = o)
-        dependencies = dag%depends_on(v)
-
-        do concurrent(w = 1:size(dependencies))
-          associate(w_dependencies => dependencies(w))
-            if (.not. any(w_dependencies == hybrid%s)) hybrid = depth_first_search(w_dependencies, [d, v], hybrid%o)
-          end associate
-        end do
-
-        if (.not. any(v == hybrid%o)) hybrid%o = [v, hybrid%o]
-        hybrid = searched_and_ordered_t(s = [v, hybrid%s], o = hybrid%o)
-      end block
+      hybrid = searched_and_ordered_t(s = [integer::], o = o)
+
+      associate(dependencies => dag%depends_on(v))
+        block
+          integer w
+          do concurrent(w = 1:size(dependencies))
+            associate(w_dependencies => dependencies(w))
+              if (.not. any(w_dependencies == hybrid%s)) hybrid = depth_first_search(w_dependencies, [d, v], hybrid%o)
+            end associate
+          end do
+        end block
+      end associate
+
+      if (.not. any(v == hybrid%o)) hybrid%o = [v, hybrid%o]
+      hybrid = searched_and_ordered_t(s = [v, hybrid%s], o = hybrid%o)
 
     end function