[erlang-questions] Good form

Richard O'Keefe raoknz@REDACTED
Fri Mar 15 02:56:10 CET 2019


At one extreme we reach the 'point-free' style liked in Haskell,
or the 'pipeful' style common in F#.
There is a place for that sort of thing,
but I'm not convinced that code meant for other people
to read is that place.
Think of introducing variables as an opportunity to make
your code easier to understand, not as a cost.

On Fri, 15 Mar 2019 at 11:36, Hugo Mills <hugo@REDACTED> wrote:

> On Thu, Mar 14, 2019 at 06:12:35PM -0400, Donald Steven wrote:
> > Sometimes, when a variable is bound then used only once in a
> > function call, it seems easier just to just use what it is bound to
> > directly in the function call, bypassing the first step.
> >
> > Here's an example:
> >
> > getSound(Event)
> ->element(evaluate:probableElement(evaluate:probabilities(maps:get(elementTag,
> > Event))),
> > hd(lists:nth(maps:get(templateTag, Event),
> > agitatedSoundResources(maps:get(scalarTag, Event),
> > maps:get(registerTag,
> > Event), maps:get(transpositionTag, Event))))).
> >
> > Alternatively, I could have declared, for example, a raft of
> > variable like ElementNumber, ElementTag, TemplateTag, etc.
> >
> > I realize that this all-in-one-compact version tends towards
> > inscrutabel c code liek &X++ ?.
> >
> > How do you approach the temptation to avoid discrete steps in favor
> > of compactness?
>
>    I don't find it tempting at all. :)
>
>    The discrete steps can be useful documentation, because you can
> give the interim variables meaningful names, explaining (a little)
> what it is that you're doing.
>
>    It also helps to break up the calls for formatting and readability,
> particularly if you have functions with multiple parameters in the
> sequence.
>
>    Hugo.
>
> --
> Hugo Mills             | The most exciting phrase to hear in science, the
> one
> hugo@REDACTED carfax.org.uk | that heralds new discoveries, is not "Eureka!",
> but
> http://carfax.org.uk/  | "That's funny..."
> PGP: E2AB1DE4          |                                          Isaac
> Asimov
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