generic isless

Author: ogauthe

NDTensors/src/lib/SymmetrySectors/src/sector_product.jl

@@ -80,16 +80,10 @@ function arguments_product(s1, s2)
   return throw(ArgumentError("Mixing non-empty storage types is illegal"))
 end
 
-arguments_isless(s1, s2) = isless(sym_arguments_insert_unspecified(s1, s2)...)
-function arguments_isless(t::Tuple, nt::NamedTuple)
-  isempty(nt) && return arguments_isless(t, ())
-  isempty(t) && return arguments_isless((;), nt)
-  return throw(ArgumentError("Mixing non-empty storage types is illegal"))
-end
-function arguments_isless(nt::NamedTuple, t::Tuple)
-  isempty(nt) && return arguments_isless((), t)
-  isempty(t) && return arguments_isless(nt, (;))
-  return throw(ArgumentError("Mixing non-empty storage types is illegal"))
+function arguments_isless(a1, a2)
+  isempty(a1) && return _arguments_isless(empty(a2), a2)
+  isempty(a2) && return _arguments_isless(a1, empty(a1))
+  return isless(sym_arguments_insert_unspecified(a1, a2)...)
 end
 
 # =================================  Cartesian Product  ====================================
@@ -189,6 +183,9 @@ function arguments_insert_unspecified(t1::Tuple, t2::Tuple)
   return (t1..., trivial.(t2[(n1 + 1):end])...)
 end
 
+function _arguments_isless(t1::Tuple, t2::Tuple)
+  return isless(sym_arguments_insert_unspecified(t1, t2)...)
+end
 # ===========================  Dictionary-like implementation  =============================
 function SectorProduct(nt::NamedTuple)
   arguments = sort_keys(nt)
@@ -240,3 +237,7 @@ function shared_arguments_fusion_rule(shared1::NT, shared2::NT) where {NT<:Named
   tuple_fused = shared_arguments_fusion_rule(values(shared1), values(shared2))
   return map_blocklabels(SectorProduct ∘ NT ∘ arguments ∘ SectorProduct, tuple_fused)
 end
+
+function _arguments_isless(nt1::NamedTuple, nt2::NamedTuple)
+  return isless(sym_arguments_insert_unspecified(nt1, nt2)...)
+end

NDTensors/src/lib/SymmetrySectors/test/test_sector_product.jl

@@ -546,8 +546,8 @@ end
   sA1 = SectorProduct(; A=U1(1))
 
   @test sA1 != st1
-  @test_throws ArgumentError sA1 < st1
-  @test_throws ArgumentError st1 < sA1
+  @test_throws MethodError sA1 < st1
+  @test_throws MethodError st1 < sA1
   @test_throws MethodError st1 ⊗ sA1
   @test_throws MethodError sA1 ⊗ st1
   @test_throws ArgumentError st1 × sA1