How to construct a singleton with properties

How to construct a singleton with properties.ipynb

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      "source": "module A\n\nstruct Singleton end\nconst singleton = Singleton()\n\nBase.getproperty(::Singleton, s::Symbol) = getproperty_singleton(Val(s))\ngetproperty_singleton(::Val{:nrows}) = 0\ngetproperty_singleton(::Val{:ncols}) = 0\ngetproperty_singleton(::Val{:rep}) = [0.0]\n\nBase.propertynames(::Singleton) = [:nrows, :ncols, :reo]\n\nfunction Base.show(io::IO, x::Singleton)\n    print(io, \"Singleton(nrows = \", x.nrows, \", ncols = \", x.ncols, \", rep = \", x.rep, ')')\nend\n\nend\n\n@show A.singleton === A.Singleton() === A.Singleton()\n@show A.singleton\n@show A.singleton.nrows, A.singleton.ncols, A.singleton.rep;",
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          "text": "A.singleton === A.Singleton() === A.Singleton() = true\nA.singleton = Singleton(nrows = 0, ncols = 0, rep = [0.0])\n(A.singleton.nrows, A.singleton.ncols, A.singleton.rep) = (0, 0, [0.0])\n",
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      "source": "module B\n\nusing GenerateProperties\n\nstruct Singleton end\nconst singleton = Singleton()\n\n@generate_properties Singleton begin\n    @get nrows = 0\n    @get ncols = 0\n    @get rep = [0.0]\nend\n\nfunction Base.show(io::IO, x::Singleton)\n    print(io, \"Singleton(nrows = \", x.nrows, \", ncols = \", x.ncols, \", rep = \", x.rep, ')')\nend\n\nend\n\n@show B.singleton === B.Singleton() === B.Singleton()\n@show B.singleton\n@show B.singleton.nrows, B.singleton.ncols, B.singleton.rep;",
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          "text": "B.singleton === B.Singleton() === B.Singleton() = true\nB.singleton = Singleton(nrows = 0, ncols = 0, rep = [0.0])\n(B.singleton.nrows, B.singleton.ncols, B.singleton.rep) = (0, 0, [0.0])\n",
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        "description": "How to construct a singleton with properties",
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