53 lines
1.3 KiB
C#
53 lines
1.3 KiB
C#
using System;
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using System.Collections.Generic;
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using System.Linq;
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public class DemoFunc
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{
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private Func<int> intFunc;
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private Func<T> AsFunc<T>(T input)
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{
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return () => input;
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}
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private T Exec<T>(Func<T> func)
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{
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return func();
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}
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public void ContrivedMethod()
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{
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Func<string> helloWorldFunc = AsFunc("Hello World!");
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var helloWorld = Exec(helloWorldFunc);
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// helloWorld == "Hello World!"
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intFunc = AsFunc(1);
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var one = Exec(intFunc);
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// one == 1);
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}
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public void SomewhatMoreRealisticMethod()
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{
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// cant use var - because we need to tell the compiler what we'll describe
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Func<IEnumerable<BooksByAuthor>, string, bool> authorExists =
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(booksByAuthor, authorName) => booksByAuthor.Any(ba => ba.Author == authorName);
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Func<IEnumerable<BooksByAuthor>, string, BooksByAuthor> getGataloguedAuthor =
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(booksByAuthor, authorName) => {
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// can do complex stuff or help in debugging
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return booksByAuthor.FirstOrDefault(ba => ba.Author == authorName);
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};
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var bas = Enumerable.Empty<BooksByAuthor>();// for conciceness
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var exits = authorExists(bas, "Homer");
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var homersBooks = getGataloguedAuthor(bas, "Homer");
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}
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}
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