fix: type instabilities

Author: MilesCranmer

ext/DynamicExpressionsSymbolicUtilsExt.jl

@@ -175,9 +175,13 @@ function Base.convert(
         findoperation(op, operators.unaops)
     end
 
-    return constructorof(N)(;
-        op=ind, children=map(x -> convert(N, x, operators; variable_names), args)
-    )
+    if length(args) == 2
+        children = map(x -> convert(N, x, operators; variable_names), (args[1], args[2]))
+        return constructorof(N)(; op=ind, children)
+    else
+        children = map(x -> convert(N, x, operators; variable_names), (only(args),))
+        return constructorof(N)(; op=ind, children)
+    end
 end
 
 _node_type(::Type{<:AbstractExpression{T,N}}) where {T,N<:AbstractExpressionNode} = N

src/Evaluate.jl

@@ -2,7 +2,8 @@ module EvaluateModule
 
 using DispatchDoctor: @stable, @unstable
 
-import ..NodeModule: AbstractExpressionNode, constructorof, max_degree, children
+import ..NodeModule:
+    AbstractExpressionNode, constructorof, max_degree, children, with_type_parameters
 import ..StringsModule: string_tree
 import ..OperatorEnumModule: OperatorEnum, GenericOperatorEnum
 import ..UtilsModule: fill_similar, counttuple, ResultOk
@@ -244,7 +245,7 @@ function eval_tree_array(
     kws...,
 ) where {T1,T2}
     T = promote_type(T1, T2)
-    tree = convert(constructorof(typeof(tree)){T}, tree)
+    tree = convert(with_type_parameters(typeof(tree), T), tree)
     cX = Base.Fix1(convert, T).(cX)
     return eval_tree_array(tree, cX, operators; kws...)
 end

src/ParametricExpression.jl

@@ -12,6 +12,7 @@ using ..ChainRulesModule: NodeTangent
 import ..NodeModule:
     constructorof,
     with_type_parameters,
+    with_max_degree,
     max_degree,
     preserve_sharing,
     leaf_copy,
@@ -121,6 +122,9 @@ end
 function with_type_parameters(::Type{N}, ::Type{T}) where {N<:ParametricNode,T}
     return ParametricNode{T,max_degree(N)}
 end
+function with_max_degree(::Type{N}, ::Val{D}) where {T,N<:ParametricNode{T},D}
+    return ParametricNode{T,D}
+end
 @unstable default_node_type(::Type{<:ParametricExpression}) = ParametricNode{T,2} where {T}
 function default_node_type(::Type{N}) where {T,N<:ParametricExpression{T}}
     return ParametricNode{T,max_degree(N)}