Deeper look at RFC7159 the JSON

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Deeper look at RFC7159: the revised specification of JSON Urabe, Shyouhei. DeNA Co., Ltd.

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New RFC to specify JSON was released last month!

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So I created a new gem

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Why another JSON library?

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So a conforming JSON library … ● MUST always generate JSON text that STRICTLY conforms the RFC, without ANY extensions such as NaNs. Otherwise that generator is not a conforming JSON library. ● MUST always understand ALL expression that the RFC permits, NO MATTER HOW strange that specific expression is, or even impossible to represent in Ruby. Otherwise that parser is not a conforming JSON library. This is hard!

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How to tackle this situation

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Line-by-line translation into racc and…

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… and 100+ acceptance tests.

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Some interesting cases include:

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This is by design, but out of date.

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Should I stop using Yajl / Oj ? ● I don't think so. ● They are useful. Just having little bugs. All programms do so more or less. I don't want to point them at finger. ● On the other hand, the library I created is strict-but-useless. It exhibits paranoia behaviour, too strict to reject converting most Ruby objects into JSON, while too tolerant to accept almost any texts, and most importantly, RUNS TOO SLOW.

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Fast enough to take 1.6+ secs for parsing 32KB

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Maybe JSON needs better trade-offs ● Proper treatments of evil escapes, like [”\uD800”], is the nightmare that causes this slow-down. ● Ignoring them only should greatly speed things up. ● JSON spec might better be updated to explicitly forbid invalid sequences, even if they are escaped. ● Everyone should stop generate such thing today.

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URLs to refer: ● http://tools.ietf.org/html/rfc7159 ● https://github.com/shyouhei/RFC7159 ● https://rubygems.org/gems/RFC7159 Thank you!