Fix nested diff2term edge case (#1166)

* Fix nested diff2term edge case * only fallback to function
JuliaSymbolics · Jun 9, 2024 · ad00b58 · ad00b58
1 parent df25344
commit ad00b58
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Showing 2 changed files with 13 additions and 5 deletions.
diff --git a/src/utils.jl b/src/utils.jl
@@ -111,23 +111,25 @@ function diff2term(O, O_metadata::Union{Dict, Nothing, Base.ImmutableDict}=nothi
         ds = nothing
     end
     d_separator = 'ˍ'
-    local opname
 
     if ds === nothing
         return maketerm(typeof(O), head(O), map(diff2term, children(O)),
                         symtype(O),  O_metadata isa Nothing ?
             metadata(O) : Base.ImmutableDict(metadata(O)..., O_metadata...))
     else
         oldop = operation(O)
-        if issym(oldop)
-            opname = string(nameof(oldop))
+        opname = if issym(oldop)
+            string(nameof(oldop))
         elseif iscall(oldop) && operation(oldop) === getindex
-            opname = string(nameof(arguments(oldop)[1]))
-            args = arguments(O)
+            string(nameof(arguments(oldop)[1]))
         elseif oldop == getindex
             args = arguments(O)
             opname = string(tosymbol(args[1]), "[", map(tosymbol, args[2:end])..., "]")
             return Sym{symtype(O)}(Symbol(opname, d_separator, ds))
+        elseif oldop isa Function
+            return nothing
+        else
+            error("diff2term case not handled: $oldop")
         end
         newname = occursin(d_separator, opname) ? Symbol(opname, ds) : Symbol(opname, d_separator, ds)
         return setname(maketerm(typeof(O), rename(oldop, newname), children(O), symtype(O), O_metadata isa Nothing ?

diff --git a/test/downstream/modeling_toolkit_utils.jl b/test/downstream/modeling_toolkit_utils.jl
@@ -26,3 +26,9 @@ D = Differential(t)
         )
     )
 )
+
+@variables x y t
+D = Differential(t)
+Symbolics.diff2term(D(x))
+Symbolics.diff2term(D(sqrt(sqrt(sqrt(+(x,y))))))
+Symbolics.diff2term(D(x+y))