Benchmark code for APL-style indexing Compat code

idxbench.jl

using Compat

function idxbench(N::Integer, idx...)
    a=rand(repmat([3], length(idx))...)
    idxbench(a, N, idx...)
end

function idxbench(a::AbstractArray, N::Integer, idx...)
    b=Compat.ArrayAPL(a)

    r = 0
    t0 = time_ns()
    for i=1:N; r += length(a[idx...]); end
    t1 = time_ns()
    ref_time = t1-t0
    print(" | ", ref_time / N)

    t0 = time_ns()
    for i=1:N; r += length(b[idx...]); end
    t1 = time_ns()
    print(" | ", (t1-t0) / ref_time)

    t0 = time_ns()
    for i=1:N; r += length(@compat a[idx...]); end
    t1 = time_ns()
    println(" | ", (t1-t0) / ref_time, " |")
    @assert r > 0
end

for init in [true, false]
    # init==true is for precompilation
    versioninfo()
    println("| #dims | #trailing ints | time plain array | rel. time `ArrayAPL` | rel.time `@compat` |")
    println("| --- | --- | --- | --- | --- |")
    for n in 1:10, trail in 0:n
        print("| ", n, " | ", trail)
        idx = [repmat(UnitRange[1:3], n-trail); repmat([1], trail)]
        # heuristic to have approximately equal runtime for every configuration
        N = VERSION >= v"0.4" ? 1e8 : 1e9
        N = init ? 1 : n==trail ? ceil(Int, N/n) : ceil(Int, N/1.8^n/n)
        idxbench(N, idx...)
    end
end