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Subsume JSON

Extend ECMA-262 syntax into a superset of JSON

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  • JSON strings can contain unescaped U+2028 LINE SEPARATOR and U+2029 PARAGRAPH SEPARATOR
  • ECMAScript strings cannot

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JSON ⊄ ECMAScript

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JSON ⊂ ECMAScript

  • JSON is defined by ECMA-404 and permanently fixed by RFC 7159
  • Only solution: change ECMAScript
    • Extend DoubleStringCharacter and SingleStringCharacter productions to allow unescaped U+2028 LINE SEPARATOR and U+2029 PARAGRAPH SEPARATOR symbols
    • Backwards compatible (SyntaxError → no SyntaxError)

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Stage 1?

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Bigger question

  • Can we get rid of U+2028 LINE SEPARATOR and U+2029 PARAGRAPH SEPARATOR as LineTerminator symbols entirely?
    • Adding use counter to V8 to gather data

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<script>� // Debug info:� // User-Agent: <% JSON.stringify(ua) %>�</script>