56 lines
1.4 KiB
Markdown
56 lines
1.4 KiB
Markdown
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Title: Javascript Foncteur
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I just discovered, this morning, how to create a Visitor in Javascript:
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A visitor is an objet who can be used like a function:
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:::javascript
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var my_foncteur = new A_Foncteur();
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my_foncteur.can_have_methods(42);
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my_foncteur("Can be called like a function");
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Implementing it in `C++` is extremly easy, using operator overloading, so
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overloading the `() operator` of an object, we have a visitor, but in
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Javascript, in the current version, we do not have operator overloading.
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So we have the following trick:
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:::javascript
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/* Don't pollute global scope too much. */
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window.your_scope = {};
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your_scope.A_Function_Object = function()
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{
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/* Prepare a closure */
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var that = this;
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this.some_data = "";
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this.foncteur = function()
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{
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/*
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** Here, `this` is from the caller, we don't care about it,
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** but the `that` is from the closure, so it's our `this`.
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*/
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alert(that.some_data);
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}
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/*
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** Add any function you need.
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*/
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this.foncteur.set_data = function(data)
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{
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/*
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** Same way to get "our" this from the closure.
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*/
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that.some_data = data;
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}
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return (this.foncteur);
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}
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/* Enjoy */
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var test = new your_scope.A_Function_Object();
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test.set_data(42);
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test();
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Enjoy!
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