Finally published this as an article after much procrastination
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In the example a*b=a+b, do you want to say that 2*3 gives 5, not 6?
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Yeah. I do. Thanks
Forgot about this syntactic sugar
fn(params....) do a, b
a + b
end
This is defining an anonymous function (a,b)->a+b can calling it like this
fn((a,b)->a+b, params...)
which leads us to
julia> f = identity() do x
x^2
end
#1 (generic function with 1 method)
julia> f(3)
9
6 Likes
Probably the most complete list of possible function definitions should be in https://github.com/invenia/ExprTools.jl/blob/master/test/function.jl I mean, it’s one of the major features of ExprTools.jl, that it can work with all functions definitions.
2 Likes
Why is that a bad use of 'functor" It reminds me a lot more of the Ocaml-interpretation than the Haskell interpretation.
Not sure if it’s a bad use. Not sure where the name originated but in math functor means something different.
Found this entertaining:
julia> (x::Int)(y) = x+y; (x::Int)(;y) = x-y;
julia> (2)(4)
8
julia> (x=2)(4)
6
julia> (x=2)(y=4)
-2
6 Likes
A couple more for fun:
julia> function fib end
fib (generic function with 0 methods)
julia> Base.getindex(f::typeof(fib), n) = n ≤ 1 ? n : f[n-1]+f[n-2]
julia> [fib[n] for n = 0:7]
8-element Vector{Int64}:
0
1
1
2
3
5
8
13
julia> Base.getproperty(::typeof(cos), θ) = cos(θ)
julia> cos.:3.14
-0.9999987317275395
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This kind of fib recursion doesn’t work in v1.5.4