Make any and all short-circuiting

fix JuliaLang#11750
fcard · Jul 8, 2015 · 30939fd · 30939fd
1 parent 896cadf
commit 30939fd
Show file tree

Hide file tree

Showing 4 changed files with 105 additions and 42 deletions.
diff --git a/base/deprecated.jl b/base/deprecated.jl
@@ -635,3 +635,17 @@ end
 
 @deprecate mmap_bitarray{N}(::Type{Bool}, dims::NTuple{N,Integer}, s::IOStream, offset::FileOffset=position(s)) mmap(s, BitArray, dims, offset)
 @deprecate mmap_bitarray{N}(dims::NTuple{N,Integer}, s::IOStream, offset=position(s)) mmap(s, BitArray, dims, offset)
+
+# 11774
+# when removing these deprecations, move them to reduce.jl, remove the depwarns and uncomment the errors.
+function nonboolean_any(itr)
+    depwarn("using non-boolean collections with any(itr) is deprecated, use reduce(|, itr) instead.", :nonboolean_any)
+    #throw(ArgumentError("any(itr) only accepts boolean collections. Use reduce(|, itr) instead."))
+    reduce(|, itr)
+end
+
+function nonboolean_all(itr)
+    depwarn("using non-boolean collections with all(itr) is deprecated, use reduce(&, itr) instead.", :nonboolean_all)
+    #throw(ArgumentError("all(itr) only accepts boolean collections. Use reduce(|, itr) instead."))
+    reduce(&, itr)
+end
diff --git a/base/functors.jl b/base/functors.jl
@@ -59,6 +59,20 @@ end
 call(f::UnspecializedFun{1}, x) = f.f(x)
 call(f::UnspecializedFun{2}, x, y) = f.f(x,y)
 
+# Special purpose functors
+
+type Predicate <: Func{1}
+    f::Function
+end
+call(pred::Predicate, x) = pred.f(x)::Bool
+
+
+immutable EqX{T} <: Func{1}
+    x::T
+end
+EqX{T}(x::T) = EqX{T}(x)
+
+call(f::EqX, y) = f.x == y
 
 #### Bitwise operators ####
 

diff --git a/base/reduce.jl b/base/reduce.jl
@@ -155,12 +155,60 @@ end
 mapreduce(f, op, A::AbstractArray) = _mapreduce(f, op, A)
 mapreduce(f, op, a::Number) = f(a)
 
-mapreduce(f, op::Function, A::AbstractArray) = _mapreduce(f, specialized_binary(op), A)
+mapreduce(f, op::Function, A::AbstractArray) = mapreduce(f, specialized_binary(op), A)
 
 reduce(op, v0, itr) = mapreduce(IdFun(), op, v0, itr)
 reduce(op, itr) = mapreduce(IdFun(), op, itr)
 reduce(op, a::Number) = a
 
+### short-circuiting specializations of mapreduce
+
+## conditions and results of short-circuiting
+
+const ShortCircuiting = Union{AndFun, OrFun}
+const ReturnsBool     = Union{EqX, Predicate}
+
+shortcircuits(::AndFun, x::Bool) = !x
+shortcircuits(::OrFun,  x::Bool) =  x
+
+shorted(::AndFun) = false
+shorted(::OrFun)  = true
+
+sc_finish(::AndFun) = true
+sc_finish(::OrFun)  = false
+
+## mapreduce definitions
+
+function mapreduce_sc_impl(f, op, itr::AbstractArray)
+    @inbounds for x in itr
+        shortcircuits(op, f(x)) && return shorted(op)
+    end
+    return sc_finish(op)
+end
+
+function mapreduce_sc_impl(f, op, itr)
+    for x in itr
+        shortcircuits(op, f(x)) && return shorted(op)
+    end
+    return sc_finish(op)
+end
+
+mapreduce_no_sc(f, op, itr::Any)           =  mapfoldl(f, op, itr)
+mapreduce_no_sc(f, op, itr::AbstractArray) = _mapreduce(f, op, itr)
+
+mapreduce_sc(f::Function,    op, itr) = mapreduce_sc(specialized_unary(f), op, itr)
+mapreduce_sc(f::ReturnsBool, op, itr) = mapreduce_sc_impl(f, op, itr)
+mapreduce_sc(f::Func{1},     op, itr) = mapreduce_no_sc(f, op, itr)
+
+mapreduce_sc(f::IdFun, op, itr) =
+    eltype(itr) <: Bool?
+        mapreduce_sc_impl(f, op, itr) :
+        mapreduce_no_sc(f, op, itr)
+
+mapreduce(f, op::ShortCircuiting, n::Number) = n
+mapreduce(f, op::ShortCircuiting, itr::AbstractArray) = mapreduce_sc(f,op,itr)
+mapreduce(f, op::ShortCircuiting, itr::Any)           = mapreduce_sc(f,op,itr)
+
 
 ###### Specific reduction functions ######
 
@@ -298,53 +346,28 @@ end
 
 ## all & any
 
-function mapfoldl(f, ::AndFun, itr)
-    for x in itr
-        !f(x) && return false
-    end
-    return true
-end
+# make sure that the identity function is defined before `any` or `all` are used
+function identity end
 
-function mapfoldl(f, ::OrFun, itr)
-    for x in itr
-        f(x) && return true
-    end
-    return false
-end
+any(itr) = any(IdFun(), itr)
+all(itr) = all(IdFun(), itr)
 
-function mapreduce_impl(f, op::AndFun, A::AbstractArray{Bool}, ifirst::Int, ilast::Int)
-    while ifirst <= ilast
-        @inbounds x = A[ifirst]
-        !f(x) && return false
-        ifirst += 1
-    end
-    return true
-end
-
-function mapreduce_impl(f, op::OrFun, A::AbstractArray{Bool}, ifirst::Int, ilast::Int)
-    while ifirst <= ilast
-        @inbounds x = A[ifirst]
-        f(x) && return true
-        ifirst += 1
-    end
-    return false
-end
-
-all(a) = mapreduce(IdFun(), AndFun(), a)
-any(a) = mapreduce(IdFun(), OrFun(), a)
-
-all(pred::Union{Callable,Func{1}}, a) = mapreduce(pred, AndFun(), a)
-any(pred::Union{Callable,Func{1}}, a) = mapreduce(pred, OrFun(), a)
+any(f::Function, itr) = any(f === identity? IdFun() : Predicate(f), itr)
+any(f::Func{1},  itr) = mapreduce_sc_impl(f, OrFun(), itr)
+any(f::IdFun,    itr) =
+    eltype(itr) <: Bool?
+        mapreduce_sc_impl(f, OrFun(), itr) :
+        nonboolean_any(itr)
 
+all(f::Function, itr) = all(f === identity? IdFun() : Predicate(f), itr)
+all(f::Func{1},  itr) = mapreduce_sc_impl(f, AndFun(), itr)
+all(f::IdFun,    itr) =
+    eltype(itr) <: Bool?
+        mapreduce_sc_impl(f, AndFun(), itr) :
+        nonboolean_all(itr)
 
 ## in & contains
 
-immutable EqX{T} <: Func{1}
-    x::T
-end
-EqX{T}(x::T) = EqX{T}(x)
-
-call(f::EqX, y) = f.x == y
 in(x, itr) = any(EqX(x), itr)
 
 const ∈ = in

diff --git a/test/reduce.jl b/test/reduce.jl
@@ -201,6 +201,18 @@ prod2(itr) = invoke(prod, Tuple{Any}, itr)
 @test reduce(&, fill(trues(5), 24))  == trues(5)
 @test reduce(&, fill(falses(5), 24)) == falses(5)
 
+@test_throws TypeError any(x->0, [false])
+@test_throws TypeError all(x->0, [false])
+
+# short-circuiting any and all
+
+let c = [0, 0], A = 1:1000
+    any(x->(c[1]=x; x==10), A)
+    all(x->(c[2]=x; x!=10), A)
+
+    @test c == [10,10]
+end
+
 # in
 
 @test in(1, Int[]) == false