functions.jl

macro anon(ex)
       esc(Expr(:(=), Expr(:call, gensym(), ex.args[1]),ex.args[2]))
end

function testn(f, n)
    s = 0.0
    for i = 1:n
        s += f(i/n)
    end
    s
end

function test_inlined(n)
    s = 0.0
    for i = 1:n
        s += (i/n+1.2)^2
    end
    s
end
println("anonymous function")
offset = 1.2
@time testn(x->(x+offset)^2, 10^7)

println("named function")
g(x) = (x+offset)^2
@time testn(g, 10^7)


println("`function` function")
function h(x)
    (x+offset)^2
end
@time testn(h, 10^7)

println("type")
type t
  x
end
t(x) = (x+offset)^2
@time testn(t, 10^7)

println("immutable")
type I
  x
end
I(x) = (x+offset)^2
@time testn(I, 10^7)

println("inlined")
@time test_inlined(10^7)


println("Second pass")

...
######## Output #########

anonymous function
elapsed time: 2.645531369 seconds (640112020 bytes allocated, 13.55% gc time)
named function
elapsed time: 3.175482231 seconds (800010776 bytes allocated, 14.05% gc time)
psuedonymous(?) function
elapsed time: 3.268614429 seconds (800011112 bytes allocated, 14.76% gc time)
`function` function
elapsed time: 3.177589198 seconds (800010776 bytes allocated, 14.16% gc time)
type
elapsed time: 3.204535867 seconds (800089032 bytes allocated, 14.88% gc time)
immutable
elapsed time: 3.148536633 seconds (800010776 bytes allocated, 14.22% gc time)
inlined
elapsed time: 0.117864924 seconds (93944 bytes allocated)
Second pass
anonymous function
elapsed time: 2.597348314 seconds (640001328 bytes allocated, 14.18% gc time)
named function
elapsed time: 3.18961047 seconds (800010600 bytes allocated, 14.01% gc time)
psuedonymous(?) function
elapsed time: 3.214356453 seconds (800011112 bytes allocated, 15.13% gc time)
`function` function
elapsed time: 3.195201891 seconds (800010600 bytes allocated, 14.11% gc time)
type
elapsed time: 3.230227238 seconds (800010600 bytes allocated, 14.70% gc time)
immutable
elapsed time: 3.202944042 seconds (800010600 bytes allocated, 14.15% gc time)
inlined
elapsed time: 0.113643034 seconds (112 bytes allocated)