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Re: Replace trivial pcase occurrences in the Emacs sources

From: Clément Pit-Claudel
Subject: Re: Replace trivial pcase occurrences in the Emacs sources
Date: Wed, 24 Oct 2018 15:00:46 -0400
User-agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.2.1

On 24/10/2018 12.00, Eli Zaretskii wrote:
>> From: Clément Pit-Claudel <address@hidden>
>> The repetition of "eq" in each "cond" branch just looks redundant to me
> If that's what bugs you, then how about
>   (setq foo (assoc bar '((1 . one) (2 . two) ...)))

This only works for constant branch bodies, and I find it marginally harder to 
read (especially if a default value is specified).
But I agree that it's not a bad solution when the branch body is constant.
For large collections, I imagine you would use a hashtable? Is that how the 
switch bytecode is implemented? IIUC, cond and pcase will be translated to a 
switch, but not assoc, even with a constant association list.

>> and I have no trouble reading the pcase forms.
> Please don't forget those who will read your code.  A code is written
> once, but read many times.  It should be readable and
> self-explanatory.

Of course. Note that I mentioned reading the pcase forms, not writing them. I'm 
just pointing out that there are readers who find pcase more readable than 
either assoc or cond with eq tests.

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