From 62b1753a54310f0d2237e1408f1839391b7529aa Mon Sep 17 00:00:00 2001
From: Tim Holy <tim.holy@gmail.com>
Date: Wed, 29 Jul 2015 09:43:54 -0500
Subject: [PATCH] Handle Dates-array arithmetic with promote_op

---
 base/dates/arithmetic.jl | 57 +++++++++++++++++-----------------------
 base/dates/periods.jl    | 43 +++---------------------------
 base/dates/types.jl      |  2 +-
 base/functors.jl         |  3 +++
 4 files changed, 32 insertions(+), 73 deletions(-)

diff --git a/base/dates/arithmetic.jl b/base/dates/arithmetic.jl
index f81780ac6340cc..48d3830e2cd231 100644
--- a/base/dates/arithmetic.jl
+++ b/base/dates/arithmetic.jl
@@ -66,41 +66,32 @@ end
 (+)(y::Period,x::TimeType) = x + y
 (-)(y::Period,x::TimeType) = x - y
 
-for op in (:.+, :.-)
-    op_ = symbol(string(op)[2:end])
-    @eval begin
-        # GeneralPeriod, AbstractArray{TimeType}
-        ($op){T<:TimeType}(x::AbstractArray{T}, y::GeneralPeriod) =
-            reshape(T[($op_)(i,y) for i in x], size(x))
-        ($op){T<:TimeType}(y::GeneralPeriod, x::AbstractArray{T}) = ($op)(x,y)
-        ($op_){T<:TimeType}(x::AbstractArray{T}, y::GeneralPeriod) = ($op)(x,y)
-        ($op_){T<:TimeType}(y::GeneralPeriod, x::AbstractArray{T}) = ($op)(x,y)
+# To avoid a switch to CompoundPeriod, we collect ranges
+(-){T<:TimeType}(x::OrdinalRange{T}, y::OrdinalRange{T}) = collect(x) - collect(y)
+(-){T<:TimeType}(x::Range{T}, y::Range{T}) = collect(x) - collect(y)
 
-	# TimeType, StridedArray{GeneralPeriod}
-        ($op){T<:TimeType,P<:GeneralPeriod}(x::StridedArray{P}, y::T) =
-            reshape(T[($op_)(i,y) for i in x], size(x))
-        ($op){P<:GeneralPeriod}(y::TimeType, x::StridedArray{P}) = ($op)(x,y)
-        ($op_){T<:TimeType,P<:GeneralPeriod}(x::StridedArray{P}, y::T) = ($op)(x,y)
-        ($op_){P<:GeneralPeriod}(y::TimeType, x::StridedArray{P}) = ($op)(x,y)
+# promotion rules
 
-        # AbstractArray{TimeType}, StridedArray{GeneralPeriod}
-        ($op_){T<:TimeType,P<:GeneralPeriod}(x::Range{T}, y::StridedArray{P}) = ($op_)(collect(x),y)
-        ($op_){T<:TimeType,P<:GeneralPeriod}(x::AbstractArray{T}, y::StridedArray{P}) =
-            reshape(TimeType[($op_)(x[i],y[i]) for i in eachindex(x, y)], promote_shape(size(x),size(y)))
-        ($op_){T<:TimeType,P<:GeneralPeriod}(y::StridedArray{P}, x::AbstractArray{T}) = ($op_)(x,y)
+for (op,F) in ((:+,  Base.AddFun),
+               (:-,  Base.SubFun),
+               (:.+, Base.DotAddFun),
+               (:.-, Base.DotSubFun))
+    @eval begin
+        Base.promote_op{P<:Period}(::$F, ::Type{P}, ::Type{P}) = P
+        Base.promote_op{P1<:Period,P2<:Period}(::$F, ::Type{P1}, ::Type{P2}) = CompoundPeriod
+        Base.promote_op{D<:Date}(::$F, ::Type{D}, ::Type{D}) = Day
+        Base.promote_op{D<:DateTime}(::$F, ::Type{D}, ::Type{D}) = Millisecond
     end
 end
 
-# TimeType, AbstractArray{TimeType}
-(.-){T<:TimeType}(x::AbstractArray{T}, y::T) = reshape(Period[i - y for i in x], size(x))
-(.-){T<:TimeType}(y::T, x::AbstractArray{T}) = -(x .- y)
-(-){T<:TimeType}(x::AbstractArray{T}, y::T) = x .- y
-(-){T<:TimeType}(y::T, x::AbstractArray{T}) = -(x .- y)
-
-# AbstractArray{TimeType}, AbstractArray{TimeType}
-(-){T<:TimeType}(x::OrdinalRange{T}, y::OrdinalRange{T}) = collect(x) - collect(y)
-(-){T<:TimeType}(x::Range{T}, y::Range{T}) = collect(x) - collect(y)
-(-){T<:TimeType}(x::AbstractArray{T}, y::Range{T}) = y - collect(x)
-(-){T<:TimeType}(x::Range{T}, y::AbstractArray{T}) = collect(x) - y
-(-){T<:TimeType}(x::AbstractArray{T}, y::AbstractArray{T}) =
-    reshape(Period[x[i] - y[i] for i in eachindex(x, y)], promote_shape(size(x),size(y)))
+for (op,F) in ((:/,   Base.RDivFun),
+               (:%,   Base.RemFun),
+               (:div, Base.IDivFun),
+               (:mod, Base.ModFun),
+               (:./,  Base.DotRDivFun),
+               (:.%,  Base.DotRemFun))
+    @eval begin
+        Base.promote_op{P<:Period}(::$F, ::Type{P}, ::Type{P}) = typeof($op(1,1))
+        Base.promote_op{P<:Period,R<:Real}(::$F, ::Type{P}, ::Type{R}) = P
+    end
+end
diff --git a/base/dates/periods.jl b/base/dates/periods.jl
index 9f0c7bb9e58a50..7ea27bdedf21a7 100644
--- a/base/dates/periods.jl
+++ b/base/dates/periods.jl
@@ -43,34 +43,14 @@ for op in (:+,:-,:lcm,:gcd)
     @eval ($op){P<:Period}(x::P,y::P) = P(($op)(value(x),value(y)))
 end
 
-for op in (:/,:%,:div,:mod)
+for op in (:/,:%,:div,:mod,:./,:.%)
     @eval begin
         ($op){P<:Period}(x::P,y::P) = ($op)(value(x),value(y))
         ($op){P<:Period}(x::P,y::Real) = P(($op)(value(x),Int64(y)))
     end
 end
-/{P<:Period}(X::StridedArray{P}, y::P) = X ./ y
-%{P<:Period}(X::StridedArray{P}, y::P) = X .% y
 *{P<:Period}(x::P,y::Real) = P(value(x) * Int64(y))
 *(y::Real,x::Period) = x * y
-.*{P<:Period}(y::Real, X::StridedArray{P}) = X .* y
-for (op,Ty,Tz) in ((:.*,Real,:P),
-                   (:./,:P,Float64), (:./,Real,:P),
-                   (:.%,:P,Int64), (:.%,Integer,:P),
-                   (:div,:P,Int64), (:div,Integer,:P),
-                   (:mod,:P,Int64), (:mod,Integer,:P))
-    sop = string(op)
-    op_ = sop[1] == '.' ? symbol(sop[2:end]) : op
-    @eval begin
-        function ($op){P<:Period}(X::StridedArray{P},y::$Ty)
-            Z = similar(X, $Tz)
-            for i = 1:length(X)
-                @inbounds Z[i] = ($op_)(X[i],y)
-            end
-            return Z
-        end
-    end
-end
 
 # intfuncs
 Base.gcdx{T<:Period}(a::T,b::T) = ((g,x,y)=gcdx(value(a),value(b)); return T(g),x,y)
@@ -186,6 +166,9 @@ function Base.string(x::CompoundPeriod)
 end
 Base.show(io::IO,x::CompoundPeriod) = print(io,string(x))
 
+*(x::CompoundPeriod,y::Real) = CompoundPeriod(Period[p*Int64(y) for p in x.periods])
+*(y::Real,x::CompoundPeriod) = x * y
+
 # E.g. Year(1) + Day(1)
 (+)(x::Period,y::Period) = CompoundPeriod(Period[x,y])
 (+)(x::CompoundPeriod,y::Period) = CompoundPeriod(vcat(x.periods,y))
@@ -201,24 +184,6 @@ GeneralPeriod = Union{Period,CompoundPeriod}
 (+)(x::GeneralPeriod) = x
 (+){P<:GeneralPeriod}(x::StridedArray{P}) = x
 
-for op in (:.+, :.-)
-    op_ = symbol(string(op)[2:end])
-    @eval begin
-        function ($op){P<:GeneralPeriod}(X::StridedArray{P},y::GeneralPeriod)
-            Z = similar(X, CompoundPeriod)
-            for i = 1:length(X)
-                @inbounds Z[i] = ($op_)(X[i],y)
-            end
-            return Z
-        end
-        ($op){P<:GeneralPeriod}(x::GeneralPeriod,Y::StridedArray{P}) = ($op)(Y,x) |> ($op_)
-        ($op_){P<:GeneralPeriod}(x::GeneralPeriod,Y::StridedArray{P}) = ($op)(Y,x) |> ($op_)
-        ($op_){P<:GeneralPeriod}(Y::StridedArray{P},x::GeneralPeriod) = ($op)(Y,x)
-        ($op_){P<:GeneralPeriod, Q<:GeneralPeriod}(X::StridedArray{P}, Y::StridedArray{Q}) =
-            reshape(CompoundPeriod[($op_)(X[i],Y[i]) for i in eachindex(X, Y)], promote_shape(size(X),size(Y)))
-    end
-end
-
 (==)(x::CompoundPeriod, y::Period) = x == CompoundPeriod(y)
 (==)(y::Period, x::CompoundPeriod) = x == y
 (==)(x::CompoundPeriod, y::CompoundPeriod) = x.periods == y.periods
diff --git a/base/dates/types.jl b/base/dates/types.jl
index ce9c7cb933ee1d..4e45fb26e0f31a 100644
--- a/base/dates/types.jl
+++ b/base/dates/types.jl
@@ -1,6 +1,6 @@
 # This file is a part of Julia. License is MIT: http://julialang.org/license
 
-abstract AbstractTime
+abstract AbstractTime <: AbstractScalar
 
 abstract Period     <: AbstractTime
 abstract DatePeriod <: Period
diff --git a/base/functors.jl b/base/functors.jl
index 18df3e5e7d19c1..a6022a9225068a 100644
--- a/base/functors.jl
+++ b/base/functors.jl
@@ -58,6 +58,9 @@ call(::DotMulFun, x, y) = x .* y
 immutable RDivFun <: Func{2} end
 call(::RDivFun, x, y) = x / y
 
+immutable DotRDivFun <: Func{2} end
+call(::RDivFun, x, y) = x ./ y
+
 immutable LDivFun <: Func{2} end
 call(::LDivFun, x, y) = x \ y