From: Matthew Kerwin <matthew@...>
Date: 2015-11-16T07:04:52+10:00
Subject: [ruby-core:71499] Re: [Ruby trunk - Feature #11690] [Open] Update Hash during multiple assignment

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On 16/11/2015 2:32 AM, <6ftdan@gmail.com> wrote:
>
> This would be most useful in scenarios where a method or proc return
multiple values.  When the method returns the values we don't normally know
the key outside where the hash assignment is.
>
> ~~~ruby
> example = proc { [{:hi => :hello}, 5] }
>
> hash = {}
>
> # Currently in Ruby with an Unknown key multiple assignment isn't an
option
> hash[????], current = example.call
>
> # We currently have to two step it
> result, current = example.call
> hash.update(result)
> ~~~
>
> But with `Hash#update=` we don't have to know the key.
>

I get the use-case, but I think the understandability of the code starts to
suffer.

What about something completely new but splat-like?

    hash[*], current = example.call

This is even better when the hash comes last, it looks more like an options
parameter:

    opts = get_default_hash
    a, b, opts[*] = example2.call

I would assume this also works in single assignment:

    opts = get_default_hash
    opts[*] = get_new_opts

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<p dir=3D"ltr"><br>
On 16/11/2015 2:32 AM, &lt;<a href=3D"mailto:6ftdan@gmail.com">6ftdan@gmail=
.com</a>&gt; wrote:<br>
&gt;<br>
&gt; This would be most useful in scenarios where a method or proc return m=
ultiple values.=C2=A0 When the method returns the values we don&#39;t norma=
lly know the key outside where the hash assignment is.<br>
&gt;<br>
&gt; ~~~ruby<br>
&gt; example =3D proc { [{:hi =3D&gt; :hello}, 5] }<br>
&gt;<br>
&gt; hash =3D {}<br>
&gt;<br>
&gt; # Currently in Ruby with an Unknown key multiple assignment isn&#39;t =
an option<br>
&gt; hash[????], current =3D example.call<br>
&gt;<br>
&gt; # We currently have to two step it<br>
&gt; result, current =3D example.call<br>
&gt; hash.update(result)<br>
&gt; ~~~<br>
&gt;<br>
&gt; But with `Hash#update=3D` we don&#39;t have to know the key.<br>
&gt;</p>
<p dir=3D"ltr">I get the use-case, but I think the understandability of the=
 code starts to suffer.</p>
<p dir=3D"ltr">What about something completely new but splat-like?</p>
<p dir=3D"ltr">=C2=A0=C2=A0=C2=A0 hash[*], current =3D example.call</p>
<p dir=3D"ltr">This is even better when the hash comes last, it looks more =
like an options parameter:</p>
<p dir=3D"ltr">=C2=A0=C2=A0=C2=A0 opts =3D get_default_hash<br>
=C2=A0=C2=A0=C2=A0 a, b, opts[*] =3D example2.call</p>
<p dir=3D"ltr">I would assume this also works in single assignment:</p>
<p dir=3D"ltr">=C2=A0=C2=A0=C2=A0 opts =3D get_default_hash<br>
=C2=A0=C2=A0=C2=A0 opts[*] =3D get_new_opts</p>

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