State the rules a reader follows on the format pages

[wu-sheng]

Why

The formats are JSON lines and JSON. A reader in another language, such as the SkyWalking OAP, builds the same asz.view document from the same files. Where the pages did not state a rule, such a reader had to find it in asz's Go code, and ended up copying what Go's libraries do: how Go decodes a null inside a list, which integer type a field has, how it trims white space, how it rounds a time to milliseconds, and how it orders map keys. The pages now state these rules, so a reader follows the pages and never the code.

What changes

Documentation only. No code, key or format changes; the formats stay sd/1, sf/1 and asz.view 1.0.

• Session Data, "Reading a record": the type of every record field, of every part field, of every dropped entry field, and of the usage values. A null is a field left out, and a reader ignores a field the page does not list, so a later version can add one. An integer is a whole number that fits in 64 bits with its sign, and ord and off are never negative. asz's reader stops at a line it cannot decode, as at a line that is not JSON. A time is RFC 3339 with a four-digit year, and times compare as the instants they name, with examples where the text order is the reverse. A reader does not have to copy what asz's code does with input asz never writes.
• Session Flow: attrs keys are written sorted, and ids and keys sort in code point order, which the page defines. The rejection list gains the provider_bodies rule that ProviderBodiesOf already applies, with null read as no bodies.
• asz.view: times round down to the millisecond; a round header's time is null when absent and 0 when it is not a time; ids compare in code point order; attrs are as the round wrote them; a data part's text is the record's readable text when it has one, a queued command's prompt included, and otherwise the data as written; white space is Unicode's White_Space property; which records give a call its result, result_state, result_bytes and failed; request_to_result_ms drops the rest of a millisecond; usage leaves out a count of zero, a dropped entry holds its what, bytes and why, and a field Session Data does not list is not copied.

Each statement was checked against the code on main: pkg/sessiondata (Record, Part, Drop, Usage, Reader.Next and its callers in internal/view), pkg/sessionflow (ProviderBodiesOf, checkRefs, the frame sort) and internal/view (Millis, millisPtr, durationMillis, fill, fillResult, readable, withoutProviderBodies, shortName). GPT-6 reviewed the pages against that code in two rounds; its three findings on them are fixed.

Tests

make check passes.