Preserve ranges.

Project.toml

@@ -1,6 +1,6 @@
 name = "Adapt"
 uuid = "79e6a3ab-5dfb-504d-930d-738a2a938a0e"
-version = "4.0.4"
+version = "4.1.0"
 
 [deps]
 LinearAlgebra = "37e2e46d-f89d-539d-b4ee-838fcccc9c8e"

src/base.jl

@@ -16,6 +16,7 @@ _adapt_tuple_structure(to, xs::Tuple) =
 _adapt_tuple_structure(to, xs::Tuple{}) = ()
 _adapt_tuple_structure(to, xs::Tuple{<:Any}) = (adapt(to, first(xs)), )
 
+
 ## Closures
 
 # two things can be captured: static parameters, and actual values (fields)
@@ -63,3 +64,22 @@ adapt_structure(to, bc::Broadcasted{Style}) where Style =
 
 adapt_structure(to, ex::Extruded) =
     Extruded(adapt(to, ex.x), ex.keeps, ex.defaults)
+
+
+## Ranges
+
+adapt_structure(to, r::UnitRange) =
+  UnitRange(adapt(to, r.start), adapt(to, r.stop))
+
+adapt_structure(to, r::Base.OneTo) = Base.OneTo(adapt(to, r.stop))
+
+adapt_structure(to, r::StepRange) =
+  StepRange(adapt(to, r.start), adapt(to, r.step), adapt(to, r.stop))
+
+adapt_structure(to, r::StepRangeLen) =
+  StepRangeLen(adapt(to, r.ref), adapt(to, r.step), r.len, r.offset)
+
+adapt_structure(to, r::Base.Slice) = Base.Slice(adapt(to, r.indices))
+
+adapt_structure(to, r::LinRange) =
+  LinRange(adapt(to, r.start), adapt(to, r.stop), r.len)

test/runtests.jl

@@ -232,3 +232,15 @@ end
     #@test_adapt SArray           [1,2,3] SArray{Tuple{3}}([1,2,3])
     @test adapt(SArray, [1,2,3]) === SArray{Tuple{3}}([1,2,3])
 end
+
+@testset "Ranges" begin
+    # normally these fall back to `convert(Array, r)`, so we only need to test
+    # that the type matches
+
+    @test adapt(Array, 1:10) === 1:10
+    @test adapt(Array, Base.OneTo(10)) === Base.OneTo(10)
+    @test adapt(Array, 1:2:10) === 1:2:10
+    @test adapt(Array, 1.:2.:10.) === 1.:2.:10.
+    @test adapt(Array, Base.Slice(1:10)) === Base.Slice(1:10)
+    @test adapt(Array, LinRange(1,2,10)) === LinRange(1,2,10)
+end