ANN LegibleLambdas.jl

Package Announcements
9

That’s a separate issue. LegibleLambdas will suffer from that issue to the same extent that regular illegible closures do. Here’s an example:

julia> using LegibleLambdas

julia> f(x) = y -> begin
           x = x + 1.0
           x + y
       end
f (generic function with 1 method)

julia> g(x) = @λ y -> begin
           x = x + 1.0
           x + y
       end
g (generic function with 1 method)

julia> let x = Ref(1), y = Ref(2)
           @btime f($x[])($y[])
           @btime g($x[])($y[])
       end
  48.969 ns (3 allocations: 48 bytes)
  48.582 ns (3 allocations: 48 bytes)
4.0

One thing that’s nice though about LegibleLambdas is that it can help diagnose this problem:

julia> g(1)
(y -> begin
          Core.Box(1) = Core.Box(1) + 1.0
          Core.Box(1) + y
      end)

Though, the ‘legible’ printing leaves something to be desired here. I basically just walked through the syntax tree and replaced x with 1, so in the presence of rebindings and such, it’s kinda nonsense. Where is says Core.Box(1), it’s really Core.Box(x).

2 Likes