Learning to work with closures. This is a construct to find out what is possible. foo(d, x, y) = d[x] = y struct Test f::Function Test(d::Dict, f::Function = (x, y) -> foo(d, x, y)) = new(f) end t = Test(Dict()) Whenever I call t.f(x, y) a key, value pair is added to the dict I pas…

Found it! t.f.d I love this language! I’m just leaving it here in case anyone else is interested.

I took me a while understanding what you did there. Interesting. I would have written it like this: foo(d, x, y) = d[x] = y struct Test f::Function end Test(d::Dict) = Test( (x,y) -> foo(d,x,y) ) t = Test(Dict()) @show t @show t.f(1,2) @show t.f @show t.f.d I am not completely sur…

It is an implementation detail that variables captured by a closure can be accessed as fields of the closure object. Ideally, you should not rely on it.

[image] Henrique_Becker: It is an implementation detail that variables captured by a closure can be accessed as fields of the closure object. What would be the minimal working example of that? This does not work, for example: a = 2 f = x -> a*x @show f(1).a Maybe that is a good opportunity …

[image] lmiq: What would be the minimal working example of that? julia> adder(x) = y -> x + y adder (generic function with 1 method) julia> adder(10).x 10

[image] lmiq: f(a,x) = x -> a*x You probably should not be taking that second argument. It is immediately shadowed by the inner closure parameter name.

[image] Henrique_Becker: You probably should not be taking that second argument. Yes, thanks. I added that trying to build a “standalone” working closure. But that makes no sense.

You may find the function dump useful in understanding new structures, the closure in this case.

I don’t think [image] Henrique_Becker: It is an implementation detail that variables captured by a closure can be accessed as fields of the closure object. Ideally, you should not rely on it. I don’t think that’s true. The docs say: “A closure is simply a callable object with field names cor…

You are looking at the Developer’s Documentation, not the User’s Manual. Accessing captured variables as fields in a closure object is an implementation detail, we have word of god on this: [image] Function factories or callable structs? 100% with one caveat: accessing the fields of a closure i…

Yeah, you’re right. I was searching the docs for “closure” and didn’t notice the result was in the Developer section. That’s pretty disappointing, cause I think it’s an awesome feature.

Accessing data in a closure?

New to Julia

lmiq February 9, 2021, 6:14pm 8

Yes, thanks. I added that trying to build a “standalone” working closure. But that makes no sense.

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Accessing data in a closure?

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