Merge pull request #631 from JuliaSymbolics/fix-array-function-type-inference

Fix `maketerm` handling of `BasicSymbolic{Array}`

Author: bowenszhu

src/types.jl

@@ -563,17 +563,18 @@ function TermInterface.maketerm(T::Type{<:BasicSymbolic}, head, args, metadata)
     # Where the result would have a symtype of Bool. 
     # Please see discussion in https://github.com/JuliaSymbolics/SymbolicUtils.jl/pull/609 
     # TODO this should be optimized.
-    new_st = if pst === Bool 
-        pst 
-    elseif pst === Any || (st === Number && pst <: st) 
+    new_st = if st <: AbstractArray
         st
-    else 
-        pst 
-    end 
+    elseif pst === Bool
+        pst
+    elseif pst === Any || (st === Number && pst <: st)
+        st
+    else
+        pst
+    end
     basicsymbolic(head, args, new_st, metadata)
 end
 
-
 function basicsymbolic(f, args, stype, metadata)
     if f isa Symbol
         error("$f must not be a Symbol")

test/basics.jl

@@ -249,6 +249,11 @@ end
     @syms x::Int y::Int 
     new_expr = SymbolicUtils.maketerm(typeof(ref_expr), (+), [x, y], nothing)
     @test symtype(new_expr) == Int64
+
+    # Check that the Array type does not get changed to AbstractArray
+    new_expr = SymbolicUtils.maketerm(
+        SymbolicUtils.BasicSymbolic{Vector{Float64}}, sin, [1.0, 2.0], nothing)
+    @test symtype(new_expr) == Vector{Float64}
 end
 
 toterm(t) = Term{symtype(t)}(operation(t), arguments(t))