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Date: Thu, 21 Jul 2016 22:56:45 +0100
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Subject: Re: [PHP-DEV] Pipe Operator v2
From: rowan.collins@gmail.com (Rowan Collins)

On 21/07/2016 22:28, Sara Golemon wrote:
> Are you picturing the return statement returning from the current
> function? Or "returning" from the current pipe chain?
>
> I think you mean the former, in which case I'd ask how that'd better/worse than:
>
> return foo() |> bar($$);


I do indeed mean returning from the current function. I went into more 
detail (perhaps too much!) on the previous thread, but the basic premise 
is the pipe operator gives you code that reads left to right. Adding an 
element where you have to jump back to the beginning of the expression 
feels like it defeats that.

You picked an example with a very short pipeline, and the "return" is 
fairly obvious; but then "return bar(foo());" is not a great candidate 
for using the operator in the first place. Take a longer example:

return loadConfig()
    |> buildDic($$)
    |> getApp($$)
    |> getRouter($$)
    |> getDispatcher($$, $request)
    |> dispatchBusinessLogic($$, $request, new Response())
    |> renderResponse($$)
    |> buildPsr7Response($$)
    |> emit($$);


If you read through that pipeline, you get down to emit($$), and then 
have to scan back up to figure out where result of that is going to end 
up. Compare:

loadConfig()
    |> buildDic($$)
    |> getApp($$)
    |> getRouter($$)
    |> getDispatcher($$, $request)
    |> dispatchBusinessLogic($$, $request, new Response())
    |> renderResponse($$)
    |> buildPsr7Response($$)
    |> emit($$)
    |> return $$;


Here you can read through all the steps in order, right up to the last 
action, which is returning the resulting value.

Even the name "pipe" is suggesting that something goes in one end, and 
comes out the other, so having the output pop out next to the input just 
feels weird.

Regards,

-- 
Rowan Collins
[IMSoP]