Support StepRange{T,U} where U is non-numeric (#32671)

With thanks to @quinnj
JuliaLang · Aug 2, 2019 · a0936f9 · a0936f9 · nanosoldier · Aug 3, 2019
1 parent 62857f8
commit a0936f9
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Showing 2 changed files with 13 additions and 3 deletions.
diff --git a/base/range.jl b/base/range.jl
@@ -777,9 +777,9 @@ end
 function intersect(r::StepRange, s::StepRange)
  if isempty(r) || isempty(s)
  return range(first(r), step=step(r), length=0)
- elseif step(s) < 0
+ elseif step(s) < zero(step(s))
  return intersect(r, reverse(s))
- elseif step(r) < 0
+ elseif step(r) < zero(step(r))
  return reverse(intersect(reverse(r), s))
  end
 
@@ -804,7 +804,7 @@ function intersect(r::StepRange, s::StepRange)
 
  g, x, y = gcdx(step1, step2)
 
- if rem(start1 - start2, g) != 0
+ if !iszero(rem(start1 - start2, g))
  # Unaligned, no overlap possible.
  return range(start1, step=a, length=0)
  end

diff --git a/test/ranges.jl b/test/ranges.jl
@@ -361,6 +361,16 @@ end
 
  @test intersect(1:3, 2) === intersect(2, 1:3) === 2:2
  @test intersect(1.0:3.0, 2) == intersect(2, 1.0:3.0) == [2.0]
+
+ @testset "Support StepRange with a non-numeric step" begin
+ start = Date(1914, 7, 28)
+ stop = Date(1918, 11, 11)
+
+ @test intersect(start:Day(1):stop, start:Day(1):stop) == start:Day(1):stop
+ @test intersect(start:Day(1):stop, start:Day(5):stop) == start:Day(5):stop
+ @test intersect(start-Day(10):Day(1):stop-Day(10), start:Day(5):stop) ==
+ start:Day(5):stop-Day(10)-mod(stop-start, Day(5))
+ end
  end
  @testset "issubset" begin
  @test issubset(1:3, 1:typemax(Int)) #32461