emit('data') best practice - nodejs

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Message from discussion emit('data') best practice
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Date: Mon, 3 Sep 2012 22:01:21 -0700
Message-ID: <CAMCMjp0HiVjLKjqZHTMchvkL_M5S-YwpeTA43g2LQO5KkRE...@mail.gmail.com>
Subject: Re: [nodejs] Re: emit('data') best practice
From: Jake Verbaten <rayn...@gmail.com>
To: nodejs@googlegroups.com
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A way to solve this is open an issue on the repository. You'll get one
concrete answer.

On Mon, Sep 3, 2012 at 9:29 PM, Mike Nichols <nichols.mik...@gmail.com>wrote:

> Thanks for your response.
> I guess my question is whether to emit a 'data' event when there isn't any
> "raw data", but the underlying reply from redis is considered to be an
> 'empty list'. The zen semantic in me asks 'is the absence of data....data'
> . :)
> But seriously, it just feels like a subscriber would always want to know
> that 'empty', not nil, was the reply.
>
>
> On Monday, September 3, 2012 8:26:20 PM UTC-7, tjholowaychuk wrote:
>>
>> IMO if the idea behind streams are to act like pipes then "data" events
>> should only be "raw" data aka Buffers (strings too I guess),
>> if it's a non-stream then whatever I guess
>>
>> On Monday, 3 September 2012 15:44:55 UTC-7, Mike Nichols wrote:
>>>
>>> When issuing a redis command which expects a multi-bulk reply but the
>>> key does not exist, one may receive the following:
>>> +OK
>>> *0
>>>
>>> The redis docs say "If the specified key does not exist, the key is
>>> considered to hold an empty list and the value 0 is sent as multi bulk
>>> count."
>>>
>>> It seems like it is proper to emit a 'data' event in a client library
>>> with the 'empty list' redis implies so that consuming code can use it in a
>>> pipeline and let the consumer handle the `empty list` there.
>>>
>>> This came from looking at 'https://github.com/tblobaum/**redis-stream<https://github.com/tblobaum/redis-stream>'
>>> where this sort of reply drops the data, thus breaking the pipeline.
>>>
>>> This leads me to the greater question on whether or not to emit 'data'
>>> for a empty value. My gut says low level libs like these _should_ emit the
>>> event with empty data but I wonder what other authors are preferring.
>>>
>>> Any opinions would be appreciated on this.
>>>
>>>  --
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A way to solve this is open an issue on the repository. You&#39;ll get one =
concrete answer.<br><br><div class=3D"gmail_quote">On Mon, Sep 3, 2012 at 9=
:29 PM, Mike Nichols <span dir=3D"ltr">&lt;<a href=3D"mailto:nichols.mike.s=
@gmail.com" target=3D"_blank">nichols.mik...@gmail.com</a>&gt;</span> wrote=
:<br>
<blockquote class=3D"gmail_quote" style=3D"margin:0 0 0 .8ex;border-left:1p=
x #ccc solid;padding-left:1ex"><div>Thanks for your response.</div>I guess =
my question is whether to emit a &#39;data&#39; event when there isn&#39;t =
any &quot;raw data&quot;, but the underlying reply from redis is considered=
 to be an &#39;empty list&#39;. The zen semantic in me asks &#39;is the abs=
ence of data....data&#39; . :)=A0<div>
But seriously, it just feels like a subscriber would always want to know th=
at &#39;empty&#39;, not nil, was the reply.=A0</div><div class=3D"HOEnZb"><=
div class=3D"h5"><div><br><br>On Monday, September 3, 2012 8:26:20 PM UTC-7=
, tjholowaychuk wrote:<blockquote class=3D"gmail_quote" style=3D"margin:0;m=
argin-left:0.8ex;border-left:1px #ccc solid;padding-left:1ex">
IMO if the idea behind streams are to act like pipes then &quot;data&quot; =
events should only be &quot;raw&quot; data aka Buffers (strings too I guess=
),<div>if it&#39;s a non-stream then whatever I guess<br><br>On Monday, 3 S=
eptember 2012 15:44:55 UTC-7, Mike Nichols  wrote:<blockquote class=3D"gmai=
l_quote" style=3D"margin:0;margin-left:0.8ex;border-left:1px #ccc solid;pad=
ding-left:1ex">
<div>When issuing a redis command which expects a multi-bulk reply but the =
key does not exist, one may receive the following:<br></div><div>+OK</div><=
div>*0</div><div><br></div><div>The redis docs say &quot;<span style=3D"col=
or:rgb(51,51,51);font-family:&#39;Helvetica Neue&#39;,sans-serif;line-heigh=
t:19px;background-color:rgb(250,250,250)">If the specified key does not exi=
st, the key is considered to hold an empty list and the value=A0</span><cod=
e style=3D"font:inherit;font-family:Menlo,Monaco,monospace;color:rgb(51,51,=
51);background-color:rgb(250,250,250)">0</code><span style=3D"color:rgb(51,=
51,51);font-family:&#39;Helvetica Neue&#39;,sans-serif;line-height:19px;bac=
kground-color:rgb(250,250,250)">=A0is sent as multi bulk count.&quot;</span=
></div>
<div><span style=3D"color:rgb(51,51,51);font-family:&#39;Helvetica Neue&#39=
;,sans-serif;line-height:19px;background-color:rgb(250,250,250)"><br></span=
></div><div>It seems like it is proper to emit a &#39;data&#39; event in a =
client library with the &#39;empty list&#39; redis implies so that consumin=
g code can use it in a pipeline and let the consumer handle the `empty list=
` there.</div>
<div><br></div><div>This came from looking at &#39;<a href=3D"https://githu=
b.com/tblobaum/redis-stream" target=3D"_blank">https://github.com/tblobaum/=
<u></u>redis-stream</a>&#39; where this sort of reply drops the data, thus =
breaking the pipeline.=A0</div>
<div><br></div><div>This leads me to the greater question on whether or not=
 to emit &#39;data&#39; for a empty value. My gut says low level libs like =
these _should_ emit the event with empty data but I wonder what other autho=
rs are preferring.</div>
<div><br></div><div>Any opinions would be appreciated on this.</div><div><b=
r></div></blockquote></div></blockquote></div>

<p></p>

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