AFAIU adding methods to @pure functions is not allowed. However I have a function mysin that I want to be able to add methods to later on and I also know that certain methods are pure. Is a purity fence like in the following snipped a sane solution to this? using BenchmarkTools Base.@pure mysin_pu…

In short, disrecommended. (because) You are asking “Is it reasonable to take a @pure function and then make it generic if it is done indirectly?” A pure function can only depend on immutable information. This also means a @pure function cannot use any global mutable state, including generic fun…

Actually, I think your proposal with mysin and mysin_pure looks totally fine. mysin is a regular generic function, and one of its methods happens to call an @pure function. That all sounds good to me. I’m not as sure about your proposed macro–if you find yourself needing to use @pure that much, it …

Also, marking “pure” a function called “mysin” is theologically frowned upon. (sorry)

Maybe unsafe?, considering that sin(Inf) throws and this answer in Can @pure functions throw an error? - #2 by jameson [image] Can @pure functions throw an error? Probably a very bad idea, as pure means we can discard or duplicate side-effects, which then also means we can transform any program …

But I wonder if it is OK to wrap a generic function when all the arguments are concrete immutable and it’s “conceptually” pure (e.g., it doesn’t throw). I mean, is @jw3126 ’s example fine if sin doesn’t throw? Applying this point in the docstring literally probably indicates no: This also means a…

Ah thanks, I thought sin(Inf) was NaN, but you are right it throws.

But then I found this example where a @pure function calls a generic function which includes a path to throw but actually is impossible to throw inside the context of the @pure function: Rationale for the `@pure`ity of `Rational{T}(x)` . So maybe it’s fine to do this? Base.@pure mysin_pure(x::Float…

Extending methods of pure function

General Usage

tkf December 20, 2018, 10:41pm 5

Maybe unsafe?, considering that sin(Inf) throws and this answer in Can @pure functions throw an error? - #2 by jameson

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Extending methods of pure function

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