A math-y notation for map-filter-reduce

Mathy.jl is a math-like DSL for broadcasting expressions and Transducers.jl:

julia> @$ + { (1:10) .^ 2 | (_ + 2) % 3 == 0 }
259

This is equivalent to

mapfoldl(Map(x -> x^2) |> Filter(x -> (x + 2) % 3 == 0), +, 1:10)

Of course, you can make it more mathy by using a proper symbol:

julia> ∑ = +;

julia> @$ ∑ { (1:10) .^ 2 | (_ + 2) % 3 == 0 }
259

See more in documentation.