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Allow me to elaborate on your point Michael (also without getting philosophical).
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<div class="">In JavaScript <font face="Menlo" class="">null</font> and <font face="Menlo" class="">undefined</font> are identifiably distinct datatypes that serve specific purposes:
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<li class=""><b class="">null</b> - This variable specifically has no value</li><li class=""><b class="">undefined</b> - The value of this variable is indeterminate (I.E. identifiably different from
<font face="Menlo" class="">null</font>)</li></ul>
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<div class="">Although the atom <font face="Menlo" class="">null</font> has no special meaning in Erlang, it does when mapped to JavaScript <span style="font-family: Menlo;" class="">null</span>; therefore to maintain accuracy, Erlang devs who also work in
JavaScript should understand and preserve this semantic difference. Likewise with Erlang <span style="font-family: Menlo;" class="">undefined</span> mapping to JavaScript <span style="font-family: Menlo;" class="">undefined</span>.</div>
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<div class="">Therefore, I submit that this semantic difference should be persevered when mapping from Erlang to JavaScript, otherwise data loss will occur, particularly when mapping from JavaScript back to Erlang.</div>
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<div class=""><font face="Menlo" class="">Erlang -> JavaScript</font></div>
<div class=""><font face="Menlo" class="">null -> null</font></div>
<div class=""><font face="Menlo" class="">undefined -> undefined</font></div>
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</font></div>
<div class=""><font face="Menlo" class="">JavaScript -> Erlang</font></div>
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<div class=""><font face="Menlo" class="">null -> null</font></div>
<div class=""><font face="Menlo" class="">undefined -> undefined</font></div>
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<div class="">This part of the mapping table at least should be bijective.</div>
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<i class=""><span lang="DE" style="font-size: 8pt; font-family: Arial, sans-serif; color: rgb(79, 129, 189);" class=""> but the words of the wise are quiet and few"<o:p class=""></o:p></span></i></div>
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<i class=""><span lang="DE" style="font-size: 8pt; font-family: Arial, sans-serif; color: rgb(79, 129, 189);" class=""> Ancient Proverb</span></i></div>
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<div class="">On 27 Jun 2018, at 08:42, Michael Nisi <<a href="mailto:michael.nisi@gmail.com" class="">michael.nisi@gmail.com</a>> wrote:</div>
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<div class="">Here’s how v8::JSON, the JSON parser in Node’s JavaScript engine, does it:<br class="">
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<blockquote type="cite" class="">JSON.stringify({})<br class="">
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'{}'<br class="">
<blockquote type="cite" class="">JSON.stringify({ name: null })<br class="">
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'{"name":null}'<br class="">
<blockquote type="cite" class="">JSON.stringify({ name: undefined })<br class="">
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'{}'<br class="">
<blockquote type="cite" class="">JSON.stringify({ name: 'Lionel' })<br class="">
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'{"name":"Lionel"}’<br class="">
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<blockquote type="cite" class="">JSON.parse('{}').name<br class="">
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undefined<br class="">
<blockquote type="cite" class="">JSON.parse('{ "name": null }').name<br class="">
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null<br class="">
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JavaScript differentiates between null and undefined, without wanting to get philosophical here.<br class="">
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Michael<br class="">
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<blockquote type="cite" class="">On 27. Jun 2018, at 09:21, <a href="mailto:zxq9@zxq9.com" class="">
zxq9@zxq9.com</a> wrote:<br class="">
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Erlang -> JSON<br class="">
- true -> true<br class="">
- false -> false<br class="">
- undefined -> null<br class="">
- Atom -> String<br class="">
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JSON -> Erlang<br class="">
- true -> true<br class="">
- false -> false<br class="">
- null -> undefined<br class="">
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