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From: Jeff Higgins <jeff@invalid.invalid>
Newsgroups: comp.lang.java.programmer
Subject: Re: OO Design Patterns vs FP
Date: Wed, 02 Oct 2013 15:55:13 -0400
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On 10/02/2013 03:31 PM, Sebastian wrote:

> Here's a useful quote from Neal Ford's article series on IBM
> developerworks:
>
> <quote>
> In the functional-programming world, traditional design patterns
> generally manifest in one of three ways:
> 1. The pattern is absorbed by the language.
> 2. The pattern solution still exists in the functional paradigm, but the
> implementation details differ.
> 3. The solution is implemented using capabilities other languages or
> paradigms lack. (For example, many solutions that use metaprogramming
> are clean and elegant — and they're not possible in Java.)
> </quote>
>
> My reading so far could be summarized like this:
>
> - Strategy
>    -- take functions (Java 8 lambdas) that implement a strategy
>    -- provide functions to choose from
>
> - Template and Factory Method
>    -- these patterns also relate to supplying concrete behavior
>    -- abstract template methods may become simple members (lambdas),
> concrete subclasses disappear
>
> - Command
>    -- disappears, because object wrapper not needed for portable
> functionality in Java 8
>
> - Chain of Responsibility and Decorator
>    -- composition of (partial) functions
>
> - Adaptor
>    -- adaptor classes can be conveniently replaced by (composable) lambdas
>
> - Visitor
>    - more complex, no direct correspondence
>    - special case for streams: reduce (decouple traversal of stream from
> operation on stream elements)
>
>
> I’d welcome any comments, additional examples of correspondences etc.
>
A bit more useful as a starting point for discussion. Thanks. :)