A command offers a greater flexibility for the control and expression of a function than the plain function mechanism. Commands can have complimentary operations, such as undo. I can provide methods to build up their parameters to support a richer lifecycle. I can build in customizations using inheritance and hooks. If I’m working in a language with objects but without first-class functions, I can provide much of that capability by using commands instead. Similarly, I can use methods and fields to help break down a complex function, even in a language that lacks nested functions, and I can
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