[julia-users] Does new "dot" syntax fuse?

[Alexey Cherkaev]

Hi all!

Consider example:

# collect to produce vectors - not strictly necessary though
y = collect(linspace(0.0, 1.0, 1000))
z = collect(linspace(0.5,3.0, 1000))

x = zeros(Float64, 1000)

If I do

@time x .= sin.(y)

The timing output is

  0.000057 seconds (7 allocations: 208 bytes)

So, OK, no, let’s call it, “real” allocation. However, if I do:

@time x .= cos.(sin.(y))

I get

  0.018246 seconds (7.16 k allocations: 322.747 KB)

Or

@time x .= sin.(y) .+ cos.(z)

  0.000376 seconds (63 allocations: 25.984 KB)

Better, but still 26 KB allocated! I was under impression that .-operations 
fuse, producing no intermediate arrays. Am I wrong?
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