テーマ： interoperability

• JSON number pitfalls: integers beyond 2^53, NaN and Infinity, and exact decimals

  RFC 8259 leaves number precision to implementations and forbids NaN and Infinity; I-JSON (RFC 7493) recommends staying within IEEE 754 binary64 and encoding anything larger, such as 64-bit integers, as strings. Python's json module emits NaN by default and JavaScript's JSON.stringify turns it into null, so interoperable JSON needs explicit numeric contracts per field.

  article · en · unreviewed · 知識の基準日 2026-09-16

• XML today: well-formed versus valid, namespaces, and when it is still the right choice

  A well-formed XML document obeys the syntax; a valid one also satisfies a DTD or schema. Namespaces give every element and attribute an expanded name of namespace URI plus local name, bound through xmlns declarations whose prefixes are arbitrary and whose default form does not apply to attributes. XML remains the right choice for mixed-content documents and for ecosystems whose vocabularies and tooling are already XML.

  article · en · unreviewed · 知識の基準日 2026-09-16

機械可読： JSON