fix: Symbolics Differential(::Number)

Author: oameye

Project.toml

@@ -13,7 +13,7 @@ Symbolics = "0c5d862f-8b57-4792-8d23-62f2024744c7"
 [compat]
 DocStringExtensions = "0.9.4"
 SymbolicUtils = "3.25"
-Symbolics = "~6.34"
+Symbolics = "6.34"
 julia = "1.10"
 Random = "1.10"
 LinearAlgebra = "1.10"

src/Symbolics/Symbolics_utils.jl

@@ -49,10 +49,14 @@ Perform substitutions in `rules` on `x`.
 Subtype = Union{Num,Equation,BasicSymbolic}
 function substitute_all(x::Subtype, rules::Dict; include_derivatives=true)
     if include_derivatives
-        rules = merge(
-            rules,
-            Dict([Differential(var) => Differential(rules[var]) for var in keys(rules)]),
-        )
+        drules = Pair[]
+        for var in keys(rules)
+            if !isa(rules[var], Number)
+                pair = Differential(var) => Differential(rules[var])
+                push!(drules, pair)
+            end
+        end
+        rules = merge(rules, Dict(drules))
     end
     return substitute(x, rules)
 end

test/HarmonicVariable.jl

@@ -73,3 +73,13 @@ end
     new_hv = substitute_all(hv, Dict(ω => 2))
     @test new_hv.ω == 2
 end
+# hv = HarmonicVariable(nat_var, "test_name", "u", ω, nat_var)
+# rules = Dict(ω => 2)
+# new_hv = substitute_all(hv, rules)
+# sym, freq = hv.symbol, hv.ω
+# substitute_all(sym, rules)
+# rules = merge(
+#     rules,
+#     Dict([Differential(var) => Differential(rules[var]) for var in keys(rules)]),
+# )
+# sym