PureYAML/Sources/PureYAMLJSON/JSON.Writer.Failure.swift
Mihaela Mihaljevic bf069fad39 feat(json): add PureYAMLJSON product, a standalone YAML <-> JSON converter
PureYAMLJSON is a separate library product layered on the core engine. JSON is
a subset of YAML 1.2, so the existing parser already reads both into one value
tree; this product adds the missing half and the value-level policy:

- JSON.Writer: a pure-Swift RFC-8259 serializer (no Foundation; WASI-clean),
  pretty or compact, rejecting non-string keys and non-finite numbers.
- JSON representability rules expressed in PureYAML's own Validation framework:
  mappingKeysAreStrings and numbersAreFinite join the core mappingKeysAreUnique.
- JSON.Validator: the representability rule set plus issues(for:)/isRepresentable.
- JSON.Convert: standalone convert(_:to:) with the round-trip law (parse ->
  validate representability -> emit -> re-parse must equal the source). To JSON
  rejects complex keys and non-finite numbers; to YAML rejects duplicate keys,
  which are legal in JSON but not in YAML.

19 tests cover the writer, the rules, and both conversion directions including
the dual-rejection edges. Carved out of the catch-all Sources/Tests paths via
exclude so the core PureYAML target is unchanged.
2026-06-25 00:33:40 +02:00

12 lines
378 B
Swift

import PureYAML
public extension PureYAML.JSON.Writer {
/// A reason a value tree cannot be written as strict JSON.
enum Failure: Error, Sendable, Equatable {
/// A YAML complex (sequence/mapping) key has no JSON object-name form.
case nonStringKey(String)
/// JSON cannot represent NaN or infinity.
case nonFiniteNumber(Double)
}
}