Generate functions inside a function from string

[chakravala]

As discussed in the other thread, in the SyntaxTree package there is now an updated genfun and @genfun for creating functions, and it now does not require Base.invokelatest, so is faster

How do I create a function from an expression

Actually, I have just figured out to do this macro without Base.invokelatest and updated SyntaxTree : julia> using SyntaxTree, BenchmarkTools julia> g = genfun(:(-(cos(x))),[:x]) (::#3) (generic function with 1 method) julia> @btime $g(1.0) 40.790 ns (0 allocations: 0 bytes) -0.5403023058681398 julia> f = @genfun -cos(x) [x] (::#3) (generic function with 1 method) julia> @btime $f(1.0) 40.801 ns (0 allocations: 0 bytes) -0.5403023058681398 Now the evaluation is much faster because it i…