Just curious, how is the container type determined for map? It seem pretty magical to me: julia> @code_warntype map(x -> x/2, rand(Int, 5)) Body::Array{Float64,1} 1995 1 ─ %1 = %new(Base.Generator{Array{Int64,1},getfield(Main, Symbol("##3#4"))}, getfield(Main, Symbol("##3#4"))(), A)::Base.Generato…

[image] galenlynch: the output type of functions determined before they are evaluated in regulat Julia It isn’t. The inference type is used for the empty case. [image] galenlynch: but how would I be able to write a function that uses the compiler’s smarts to pre-allocate an output array …

How is the output type determined in map and friends?

General Usage

Tamas_Papp August 27, 2018, 6:07am 7

BTW, with union splitting, I wonder if this is still needed. map & friends could just return Any[] for empty collections.

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How is the output type determined in map and friends?

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