Improve type stability/specifity in half-edge construction functions

Author: halleysfifthinc

src/topologies/halfedge.jl

@@ -133,7 +133,7 @@ function HalfEdgeTopology(elems::AbstractVector{<:Connectivity}; sort=true)
 
   # sort elements to make sure that they
   # are traversed in adjacent-first order
-  adjelems = sort ? adjsort(elems) : elems
+  adjelems = sort ? adjsort(elems)::typeof(elems) : elems
   eleminds = sort ? indexin(adjelems, elems) : 1:length(elems)
 
   # start assuming that all elements are
@@ -143,7 +143,7 @@ function HalfEdgeTopology(elems::AbstractVector{<:Connectivity}; sort=true)
   # initialize with first element
   half4pair = Dict{Tuple{Int,Int},HalfEdge}()
   elem = first(adjelems)
-  inds = collect(indices(elem))
+  inds::Vector{Int} = collect(indices(elem))
   v = CircularVector(inds)
   n = length(v)
   for i in 1:n
@@ -183,8 +183,8 @@ function HalfEdgeTopology(elems::AbstractVector{<:Connectivity}; sort=true)
 
   # add missing pointers
   for (e, elem) in Iterators.enumerate(adjelems)
-    inds = CCW[e] ? indices(elem) : reverse(indices(elem))
-    v = CircularVector(collect(inds))
+    inds = CCW[e] ? collect(indices(elem)) : reverse(collect(indices(elem)))
+    v = CircularVector(inds)
     n = length(v)
     for i in 1:n
       # update pointers prev and next
@@ -219,8 +219,9 @@ end
 function adjsort(elems::AbstractVector{<:Connectivity})
   # initialize list of adjacent elements
   # with first element from original list
-  list = indices.(elems)
-  adjs = Tuple[popfirst!(list)]
+  list = map(indices, elems)
+  adjs = similar(list, 0)
+  push!(adjs, popfirst!(list))
 
   # the loop will terminate if the mesh
   # is manifold, and that is always true
@@ -230,7 +231,7 @@ function adjsort(elems::AbstractVector{<:Connectivity})
     # one vertex with the last adjacent element
     found = false
     vinds = last(adjs)
-    for i in vinds
+    for i::Int in vinds
       einds = findall(e -> i ∈ e, list)
       if !isempty(einds)
         # lookup all elements that share at
@@ -251,7 +252,7 @@ function adjsort(elems::AbstractVector{<:Connectivity})
     end
   end
 
-  connect.(adjs)
+  return map(connect, adjs)
 end
 
 paramdim(::HalfEdgeTopology) = 2