from docs, eval() “Evaluate an expression in the global scope of the containing module” as follows: julia> ex = :(x + 1) :(x + 1) julia> f() = (x = 10; println(x + 1, " ", eval(ex) ); g() ) f (generic function with 1 method) julia> g() = (x = 20; println(x + 1, " ", eval(ex) ); h() ) g (generic f…

[image] tomtom: why the warntype in f2 it’s because const is missing, see here so, here’s the solution for calling scope evaluation, despite the fact that only relatively simple expression could be handled: function expr2fun(ex) vars = getvars(ex) return eval(:($Expr(:meta, :inline)…

[image] tomtom: but I wanna evaluate the expression at the calling scope There are probably workarounds to achieve what you want to achieve but the straight-forward answer is just that you cannot eval in calling scope since eval evaluates in global scope.

thanks @GunnarFarneback . Inspired by your suggestion and other searches of “local evaluation”, I come up with the following not-so-perfect solution that only works for very simple expressions: function expr2fun(ex) vars = getvars(ex) args = Expr(:tuple, vars...) return eval(:($args -> $…

[image] tomtom: vars = [vars..., getvars(arg)... ] I would recommend using append! there. [image] tomtom: I do not understand where is the penalty from??? from @code_typed , f1 and fun should be the same The difference is most likely related to inlining and/or constant propagation. Ho…

@GunnarFarneback , modified with inlining and your suggestions: function expr2fun(ex) vars = getvars(ex) args = Expr(:tuple, vars...) # return eval(:($args -> $ex) ) # is below the correct way to inline??? return eval(:($Expr(:meta, :inline); $args -> $ex) ) end getvars(ex::S…

[image] tomtom: then, how could I measure the “correct” computation time? thanks. You need to somehow stop the compiler from having so much information that it can precompute the results. You could for example try broadcasting the operations over vectors. Yes, it will add some overhead but ma…

Why are you doing this? What problem are you trying to solve? Why can’t you use a higher-order function instead?

[image] stevengj: Why are you doing this? What problem are you trying to solve? I’m trying to build a model that composed of a lot of sub-models (something like a deep learning network). Ideally a complicated expression of the whole model could be built by chaining the (simpler) expressions g…

[image] tomtom: Ideally a complicated expression of the whole model could be built by chaining the (simpler) expressions generated by the sub-models. Sounds like you could pass functions instead, since you can chain together functions as well. For example, this combines two single-variable f…

thanks @stevengj . Yes, higher order function is concise and beautiful. the problem is using the higher-order function approach would generate a lot of temporaries, e.g.: combine((a, b) -> a .+ b, c -> c .- 1, d -> d .- 3) in this case, unless super-clever-inlining is done (which I don’t know how …

Evaluation in calling scope?

General Usage

GunnarFarneback February 20, 2020, 12:15pm 3

If at all possible, use a function instead. Otherwise see Passing a string into function as a expression - #14 by GunnarFarneback.

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Evaluation in calling scope?

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