Define map_blocklabels

src/dual.jl

@@ -9,9 +9,4 @@ nondual_type(x) = nondual_type(typeof(x))
 nondual_type(T::Type) = T
 
 dual(i::LabelledInteger) = labelled(unlabel(i), dual(label(i)))
-label_dual(x) = label_dual(LabelledStyle(x), x)
-label_dual(::NotLabelled, x) = x
-label_dual(::IsLabelled, x) = labelled(unlabel(x), dual(label(x)))
-
-flip(a::AbstractUnitRange) = dual(label_dual(a))
-flip(g::AbstractGradedUnitRange) = dual(gradedrange(label_dual.(blocklengths(g))))
+flip(a::AbstractUnitRange) = dual(map_blocklabels(dual, a))

src/gradedunitrange.jl

@@ -354,3 +354,9 @@ function blockedunitrange_getindices(
   # if `a isa `GradedUnitRange`, for example.
   return mortar(blks, labelled_length.(blks))
 end
+
+map_blocklabels(::Any, a::AbstractUnitRange) = a
+function map_blocklabels(f, g::AbstractGradedUnitRange)
+  # use labelled_blocks to preserve GradedUnitRange
+  return labelled_blocks(unlabel_blocks(g), f.(blocklabels(g)))
+end

src/gradedunitrangedual.jl

@@ -27,9 +27,9 @@
 ## TODO: Define this to instantiate a dual unit range.
 ## materialize_dual(a::GradedUnitRangeDual) = materialize_dual(nondual(a))
 
-Base.first(a::GradedUnitRangeDual) = label_dual(first(nondual(a)))
-Base.last(a::GradedUnitRangeDual) = label_dual(last(nondual(a)))
-Base.step(a::GradedUnitRangeDual) = label_dual(step(nondual(a)))
+Base.first(a::GradedUnitRangeDual) = dual(first(nondual(a)))
+Base.last(a::GradedUnitRangeDual) = dual(last(nondual(a)))
+Base.step(a::GradedUnitRangeDual) = dual(step(nondual(a)))
 
 Base.view(a::GradedUnitRangeDual, index::Block{1}) = a[index]
 
@@ -40,7 +40,7 @@
 end
 
 function blockedunitrange_getindices(a::GradedUnitRangeDual, indices::Integer)
-  return label_dual(getindex(nondual(a), indices))
+  return dual(getindex(nondual(a), indices))
 end
 
 function blockedunitrange_getindices(a::GradedUnitRangeDual, indices::Block{1})
@@ -123,8 +123,8 @@
 end
 
 BlockArrays.blockaxes(a::GradedUnitRangeDual) = blockaxes(nondual(a))
-BlockArrays.blockfirsts(a::GradedUnitRangeDual) = label_dual.(blockfirsts(nondual(a)))
-BlockArrays.blocklasts(a::GradedUnitRangeDual) = label_dual.(blocklasts(nondual(a)))
+BlockArrays.blockfirsts(a::GradedUnitRangeDual) = dual.(blockfirsts(nondual(a)))
+BlockArrays.blocklasts(a::GradedUnitRangeDual) = dual.(blocklasts(nondual(a)))
 function BlockArrays.findblock(a::GradedUnitRangeDual, index::Integer)
   return findblock(nondual(a), index)
 end
@@ -138,3 +138,7 @@
 function unlabel_blocks(a::GradedUnitRangeDual)
   return unlabel_blocks(nondual(a))
 end
+
+function map_blocklabels(f, g::GradedUnitRangeDual)
+  return dual(map_blocklabels(f, dual(g)))
+end

src/labelledunitrangedual.jl

@@ -8,10 +8,12 @@ end
 dual(a::LabelledUnitRange) = LabelledUnitRangeDual(a)
 nondual(a::LabelledUnitRangeDual) = a.nondual_unitrange
 dual(a::LabelledUnitRangeDual) = nondual(a)
-label_dual(::IsLabelled, a::LabelledUnitRangeDual) = dual(label_dual(nondual(a)))
 isdual(::LabelledUnitRangeDual) = true
 blocklabels(la::LabelledUnitRangeDual) = [label(la)]
 
+map_blocklabels(f, la::LabelledUnitRange) = labelled(unlabel(la), f(label(la)))
+map_blocklabels(f, lad::LabelledUnitRangeDual) = dual(map_blocklabels(f, nondual(lad)))
+
 function nondual_type(
   ::Type{<:LabelledUnitRangeDual{<:Any,NondualUnitRange}}
 ) where {NondualUnitRange}

test/test_dual.jl

@@ -50,17 +50,24 @@ Base.isless(c1::U1, c2::U1) = c1.n < c2.n
 
   a = 1:3
   ad = dual(a)
+  af = flip(a)
   @test !isdual(a)
   @test !isdual(ad)
+  @test !isdual(af)
   @test ad isa UnitRange
+  @test af isa UnitRange
   @test space_isequal(ad, a)
+  @test space_isequal(af, a)
 
   a = blockedrange([2, 3])
   ad = dual(a)
+  af = flip(a)
   @test !isdual(a)
   @test !isdual(ad)
   @test ad isa BlockedOneTo
+  @test af isa BlockedOneTo
   @test blockisequal(ad, a)
+  @test blockisequal(af, a)
 end
 
 @testset "LabelledUnitRangeDual" begin