Added logical indexing to subarrays. Fix JuliaLang#4763

Author: ivarne

base/subarray.jl

@@ -277,6 +277,16 @@ function getindex{T,S<:Integer}(s::SubArray{T,1}, I::AbstractVector{S})
     getindex(s.parent, t)
 end
 
+function getindex{T}(s::SubArray{T,1}, I::AbstractVector{Bool})
+    t = Array(T, 0)
+    for i = 1:length(I)
+        if I[i]
+            push!(t, s.parent[s.first_index + (i-1)*s.strides[1]])
+        end
+    end
+    t
+end
+
 function translate_indexes(s::SubArray, I::Union(Real,AbstractArray)...)
     n = length(I)
     newindexes = Any[s.indexes...]

test/arrayops.jl

@@ -305,6 +305,10 @@ p = permutedims(s, [2,1])
 @test p[1,1]==a[2,2] && p[1,2]==a[3,2]
 @test p[2,1]==a[2,3] && p[2,2]==a[3,3]
 
+a = [1:10]
+b = sub(a, 5:8)
+@test filter(x -> x < 7, b) == [5, 6]
+
 ## ipermutedims ##
 
 tensors = {rand(1,2,3,4),rand(2,2,2,2),rand(5,6,5,6),rand(1,1,1,1)}