Fix type assertion to be of Node's type

Author: MilesCranmer

src/EvaluateEquation.jl

@@ -472,11 +472,11 @@ function eval(current_node)
     that it was not defined for.
 """
 function eval_tree_array(
-    tree, cX::AbstractArray{T,N}, operators::GenericOperatorEnum
-) where {T,N}
+    tree::Node{T1}, cX::AbstractArray{T2,N}, operators::GenericOperatorEnum
+) where {T1,T2,N}
     if tree.degree == 0
         if tree.constant
-            return (tree.val::T), true
+            return (tree.val::T1), true
         else
             if N == 1
                 return cX[tree.feature], true

test/test_tensor_operators.jl

@@ -34,3 +34,11 @@ tree = Node(1, c1)
 tree = Node(1, Node(1, c1), x1)
 @test repr(tree) == "vec_add(vec_square([1.0, 2.0, 3.0]), x1)"
 @test tree(X) == [3.0, 6.0, 11.0]
+
+# Also test mixed scalar and floats:
+c2 = Node(T; val=2.0)
+@test repr(c2) == "2.0"
+tree = vec_add(vec_add(c1, x1), c2)
+@test repr(tree) == "vec_add(vec_add([1.0, 2.0, 3.0], x1), 2.0)"
+tree(X)
+@test tree(X) == [5.0, 6.0, 7.0]