Tests for CachedIterator (#373)

* Tests for CachedIterator

* Tests with BlockInterlacer

Author: jishnub

src/LinearAlgebra/helper.jl

@@ -571,9 +571,11 @@ end
 
 eltype(it::Type{<:CachedIterator{T}}) where {T} = T
 
-Base.IteratorSize(::Type{<:CachedIterator{<:Any,IT}}) where {IT} = Base.IteratorSize(IT)
+function Base.IteratorSize(::Type{<:CachedIterator{<:Any,IT}}) where {IT}
+    Base.IteratorSize(IT) isa Base.IsInfinite ? Base.IsInfinite() : Base.HasLength()
+end
 
-Base.keys(c::CachedIterator) = keys(c.iterator)
+Base.keys(c::CachedIterator) = oneto(length(c))
 
 iterate(it::CachedIterator) = iterate(it,1)
 function iterate(it::CachedIterator,st::Int)
@@ -589,30 +591,12 @@ function getindex(it::CachedIterator, k)
     if mx > length(it) || mx < 1
         throw(BoundsError(it,k))
     end
-    resize!(it,isempty(k) ? 0 : mx).storage[k]
-end
-
-function findfirst(f::Function,A::CachedIterator)
-    k=1
-    for c in A
-        if f(c)
-            return k
-        end
-        k+=1
-    end
-    return 0
+    v = resize!(it, mx)
+    v.storage[k]
 end
 
-function findfirst(A::CachedIterator,x)
-    k=1
-    for c in A
-        if c == x
-            return k
-        end
-        k+=1
-    end
-    return 0
-end
+@deprecate findfirst(A::CachedIterator, x) findfirst(x, A::CachedIterator)
+findfirst(x::T, A::CachedIterator{T}) where {T} = findfirst(==(x), A)
 
 length(A::CachedIterator) = length(A.iterator)
 

test/runtests.jl

@@ -505,7 +505,7 @@ end
                 blk = ApproxFunBase.block(t, i)
                 @test i ∈ ApproxFunBase.blockrange(t, blk)
                 @test vi == t[i]
-                @test findfirst(t, vi) == i
+                @test findfirst(vi, t) == i
             end
         end
         @testset "nD" begin
@@ -525,7 +525,7 @@ end
         v = collect(Iterators.take(t, 16))
         @test eltype(v) == eltype(t)
         @testset for (i, vi) in enumerate(v)
-            @test findfirst(t, vi) == i
+            @test findfirst(vi, t) == i
         end
     end
     @testset "cache" begin
@@ -539,5 +539,38 @@ end
     end
 end
 
+@testset "CachedIterator" begin
+    v = ApproxFunBase.CachedIterator(1:4)
+    @test Base.IteratorSize(v) == Base.HasLength()
+    @test length(v) == 4
+    @test eltype(v) == Int
+    @test findfirst(3, v) == 3
+    vs = collect(v)
+    @test vs == [1:4;]
+    @test eltype(vs) == Int
+
+    v = ApproxFunBase.CachedIterator(Iterators.take(1:14, 4))
+    @test Base.IteratorSize(v) == Base.HasLength()
+    @test length(v) == 4
+    @test eltype(v) == Int
+    @test findfirst(3, v) == 3
+    vs = collect(v)
+    @test vs == [1:4;]
+    @test eltype(vs) == Int
+
+    v = ApproxFunBase.CachedIterator(1:∞)
+    @test Base.IteratorSize(v) == Base.IsInfinite()
+    @test isinf(length(v))
+    @test eltype(v) == Int
+    @test findfirst(3, v) == 3
+
+    s = PointSpace(1:4) + PointSpace(1:4)
+    b = ApproxFunBase.BlockInterlacer(s);
+    it = ApproxFunBase.CachedIterator(b)
+    # Test that the iterator isn't stateful
+    @test collect(it) == collect(Iterators.take(it, length(it)))
+    @test collect(it) == collect(b)
+end
+
 @time include("ETDRK4Test.jl")
 include("show.jl")