From f1f0ef615a494667b7e1439de4db1856afd4d48b Mon Sep 17 00:00:00 2001
From: "Steven G. Johnson" <stevenj@mit.edu>
Date: Mon, 26 May 2014 16:32:17 -0400
Subject: [PATCH 1/2] add +/- for FloatRange (fix #6973)

---
 base/operators.jl | 33 +++++++++++++++++++++++++++++++++
 base/range.jl     | 21 ++++++++++-----------
 test/ranges.jl    |  9 +++++++++
 3 files changed, 52 insertions(+), 11 deletions(-)

diff --git a/base/operators.jl b/base/operators.jl
index 98ede76cd482f..1c1b3a7cd9d80 100644
--- a/base/operators.jl
+++ b/base/operators.jl
@@ -313,6 +313,39 @@ to_index(I::(Any,Any,Any,Any)) = (to_index(I[1]), to_index(I[2]), to_index(I[3])
 to_index(I::Tuple) = map(to_index, I)
 to_index(i) = error("invalid index: $i")
 
+# Addition/subtraction of ranges
+for f in (:+, :-)
+    @eval begin
+        function $f(r1::OrdinalRange, r2::OrdinalRange)
+            r1l = length(r1)
+            r1l == length(r2) || error("argument dimensions must match")
+            range($f(r1.start,r2.start), $f(step(r1),step(r2)), r1l)
+        end
+
+        function $f{T}(r1::FloatRange{T}, r2::FloatRange{T})
+            len = r1.len
+            len == r2.len || error("argument dimensions must match")
+            divisor1, divisor2 = r1.divisor, r2.divisor
+            if divisor1 == divisor2
+                FloatRange{T}($f(r1.start,r2.start), $f(r1.step,r2.step),
+                              len, divisor1)
+            else
+                d1 = int(divisor1)
+                d2 = int(divisor2)
+                d = lcm(d1,d2)
+                s1 = div(d,d1)
+                s2 = div(d,d2)
+                FloatRange{T}($f(r1.start*s1, r2.start*s2),
+                              $f(r1.step*s1, r2.step*s2),  len, d)
+            end
+        end
+
+        $f(r1::FloatRange, r2::FloatRange) = $f(promote(r1,r2)...)
+        $f(r1::FloatRange, r2::OrdinalRange) = $f(promote(r1,r2)...)
+        $f(r1::OrdinalRange, r2::FloatRange) = $f(promote(r1,r2)...)
+    end
+end
+
 # vectorization
 
 macro vectorize_1arg(S,f)
diff --git a/base/range.jl b/base/range.jl
index 43b1b75c91c95..97a1f42e54510 100644
--- a/base/range.jl
+++ b/base/range.jl
@@ -437,18 +437,17 @@ end
 ./(r::OrdinalRange, x::Real) = range(r.start/x, step(r)/x, length(r))
 ./(r::FloatRange, x::Real)   = FloatRange(r.start/x, r.step/x, r.len, r.divisor)
 
-# TODO: better implementations for FloatRanges?
-function +(r1::OrdinalRange, r2::OrdinalRange)
-    r1l = length(r1)
-    r1l == length(r2) || error("argument dimensions must match")
-    range(r1.start+r2.start, step(r1)+step(r2), r1l)
-end
+promote_rule{T1,T2}(::Type{FloatRange{T1}},::Type{FloatRange{T2}}) =
+    FloatRange{promote_type(T1,T2)}
+convert{T}(::Type{FloatRange{T}}, r::FloatRange) =
+    FloatRange{T}(r.start,r.step,r.len,r.divisor)
 
-function -(r1::OrdinalRange, r2::OrdinalRange)
-    r1l = length(r1)
-    r1l == length(r2) || error("argument dimensions must match")
-    range(r1.start-r2.start, step(r1)-step(r2), r1l)
-end
+promote_rule{F,OR<:OrdinalRange}(::Type{FloatRange{F}}, ::Type{OR}) =
+    FloatRange{promote_type(F,eltype(OR))}
+convert{T}(::Type{FloatRange{T}}, r::OrdinalRange) =
+    FloatRange{T}(start(r), step(r), length(r), one(T))
+
+# +/- of ranges is defined in operators.jl (to be able to use @eval etc.)
 
 ## non-linear operations on ranges ##
 
diff --git a/test/ranges.jl b/test/ranges.jl
index 8379eaab90218..74afc963e1398 100644
--- a/test/ranges.jl
+++ b/test/ranges.jl
@@ -283,3 +283,12 @@ end
 
 # issue #6364
 @test length((1:64)*(pi/5)) == 64
+
+# issue #6973
+let r1 = 1.0:0.1:2.0, r2 = 1.0f0:0.2f0:3.0f0, r3 = 1:2:21
+    @test r1 + r1 == 2*r1
+    @test r1 + r2 == 2.0:0.3:5.0
+    @test (r1 + r2) - r2 == r1
+    @test r1 + r3 == convert(FloatRange{Float64}, r3) + r1
+    @test r3 + r3 == 2 * r3
+end

From 206881eeed7455f987572bb7ce6c1dcf73054837 Mon Sep 17 00:00:00 2001
From: Jeff Bezanson <jeff.bezanson@gmail.com>
Date: Tue, 27 May 2014 17:04:03 -0400
Subject: [PATCH 2/2] fix FloatRange{T}+FloatRange{T} definition

---
 base/operators.jl | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/base/operators.jl b/base/operators.jl
index 1c1b3a7cd9d80..733b326e116c2 100644
--- a/base/operators.jl
+++ b/base/operators.jl
@@ -322,7 +322,7 @@ for f in (:+, :-)
             range($f(r1.start,r2.start), $f(step(r1),step(r2)), r1l)
         end
 
-        function $f{T}(r1::FloatRange{T}, r2::FloatRange{T})
+        function $f{T<:FloatingPoint}(r1::FloatRange{T}, r2::FloatRange{T})
             len = r1.len
             len == r2.len || error("argument dimensions must match")
             divisor1, divisor2 = r1.divisor, r2.divisor