[LabelledNumbers] Drop labels more aggressively in binary operations (#…

…1367)

NDTensors/src/lib/LabelledNumbers/src/labelled_interface.jl

@@ -33,41 +33,30 @@ labelled_oneunit(x) = set_value(x, one(x))
 # encoded in the type.
 labelled_oneunit(type::Type) = error("Not implemented.")
 
-labelled_mul(x, y) = labelled_binary_op(*, x, y)
-labelled_add(x, y) = labelled_binary_op(+, x, y) #labelled_add(LabelledStyle(x), x, LabelledStyle(y), y)
-labelled_minus(x, y) = labelled_binary_op(-, x, y) #labelled_add(LabelledStyle(x), x, LabelledStyle(y), y)
-
 function labelled_binary_op(f, x, y)
   return labelled_binary_op(f, LabelledStyle(x), x, LabelledStyle(y), y)
 end
-labelled_binary_op(f, ::IsLabelled, x, ::IsLabelled, y) = f(unlabel(x), unlabel(y))
-labelled_binary_op(f, ::IsLabelled, x, ::NotLabelled, y) = set_value(x, f(unlabel(x), y))
-labelled_binary_op(f, ::NotLabelled, x, ::IsLabelled, y) = set_value(y, f(x, unlabel(y)))
+labelled_binary_op(f, ::LabelledStyle, x, ::LabelledStyle, y) = f(unlabel(x), unlabel(y))
 
 # TODO: This is only needed for older Julia versions, like Julia 1.6.
 # Delete once we drop support for older Julia versions.
-# TODO: Define in terms of `set_value`?
 labelled_minus(x) = set_value(x, -unlabel(x))
 
 # TODO: This is only needed for older Julia versions, like Julia 1.6.
 # Delete once we drop support for older Julia versions.
 labelled_hash(x, h::UInt64) = hash(unlabel(x), h)
 
-for (f, labelled_f) in [(:div, :labelled_div), (:/, :labelled_division)]
-  @eval begin
-    $labelled_f(x, y) = $labelled_f(LabelledStyle(x), x, LabelledStyle(y), y)
-    $labelled_f(::IsLabelled, x, ::IsLabelled, y) = $f(unlabel(x), unlabel(y))
-    $labelled_f(::IsLabelled, x, ::NotLabelled, y) = labelled($f(unlabel(x), y), label(x))
-    $labelled_f(::NotLabelled, x, ::IsLabelled, y) = $f(x, unlabel(y))
-  end
-end
-
-for f in [:isequal, :isless]
-  labelled_f = Symbol(:labelled_, f)
+for (fname, f) in [
+  (:mul, :*),
+  (:add, :+),
+  (:minus, :-),
+  (:div, :/),
+  (:division, :÷),
+  (:isequal, :isequal),
+  (:isless, :isless),
+]
+  labelled_fname = Symbol(:(labelled_), fname)
   @eval begin
-    $labelled_f(x, y) = $labelled_f(LabelledStyle(x), x, LabelledStyle(y), y)
-    $labelled_f(::IsLabelled, x, ::IsLabelled, y) = $f(unlabel(x), unlabel(y))
-    $labelled_f(::IsLabelled, x, ::NotLabelled, y) = $f(unlabel(x), y)
-    $labelled_f(::NotLabelled, x, ::IsLabelled, y) = $f(x, unlabel(y))
+    $labelled_fname(x, y) = labelled_binary_op($f, x, y)
   end
 end

NDTensors/src/lib/LabelledNumbers/test/runtests.jl

@@ -12,30 +12,30 @@ using Test: @test, @testset
     @test !islabelled(unlabel(x))
 
     @test x * 2 == 4
-    @test label(x * 2) == "x"
+    @test !islabelled(x * 2)
     @test 2 * x == 4
-    @test label(2 * x) == "x"
+    @test !islabelled(2 * x)
     @test x * x == 4
     @test !islabelled(x * x)
 
     @test x + 3 == 5
-    @test label(x + 3) == "x"
+    @test !islabelled(x + 3)
     @test 3 + x == 5
-    @test label(3 + x) == "x"
+    @test !islabelled(3 + x)
     @test x + x == 4
     @test !islabelled(x + x)
 
     @test x - 3 == -1
-    @test label(x - 3) == "x"
+    @test !islabelled(x - 3)
     @test 3 - x == 1
-    @test label(3 - x) == "x"
+    @test !islabelled(3 - x)
     @test x - x == 0
     @test !islabelled(x - x)
 
     @test x / 2 == 1
-    @test label(x / 2) == "x"
+    @test !islabelled(x / 2)
     @test x ÷ 2 == 1
-    @test label(x ÷ 2) == "x"
+    @test !islabelled(x ÷ 2)
     @test -x == -2
     @test hash(x) == hash(2)
     @test zero(x) == false