The ported engine wins every conflict: main's post-fork patches to the
hand-rolled Scanner and TokenEventParser land on deleted files and are
dropped; their behaviors are carried by the port and guarded by the
whole-suite conformance gate (402/402 passing).
Merge adaptations, all gates green (style, namespacing, forbidden
patterns, changelog, roadmap, swiftformat, swiftlint strict, build,
full test suite, whole-suite conformance sweep):
- PureYAMLJSON representability rules move onto the Check algebra,
replacing the retired legacy Rule type.
- The permissive tag-handle pre-pass is removed; the port rejects an
undefined handle at parse time (suite case QLJ7) and the validation
report carries it as a parse diagnostic.
- EventStreamComposer's nested types split one-per-file per the
namespacing gate.
- Tests pinned to old-engine behavior were re-verified against the
reference and updated: libyaml rejects an explicit-key continuation
ending at a value colon, and suite case QB6E requires rejecting a
quoted continuation at column 0.
- CHANGELOG unreleased entries from both lines are preserved in two
groups with a provenance note.
Closes#1, closes#3
A tag shorthand using a named handle (`!handle!suffix`) must be declared by a
`%TAG` directive in the document that uses it; the handle does not carry across
documents (YAML 1.2). The parser was permissive but silent here, so an
undeclared handle passed unnoticed.
- Scope tag handles per document: a `%TAG` handle now applies only to the
document it precedes (merged onto the defaults at the document start, cleared
at the boundary) instead of accumulating across the whole stream. A directive
repeated for each document keeps working, as the suite requires.
- Detect the named-handle form before the primary-handle fallback (which
previously masked `!prefix!x` as a local tag) and record an undeclared handle.
The parse stays permissive: it still yields a value, and
`PureYAML.validationReport` surfaces the issue as an `undefinedTagHandle`
error. The check reads the scanner's tokens, so it is exact: a `!x!` inside a
scalar or comment is never flagged.
Extracts `Scanner.State` and the tag helpers into their own files to keep each
source file within the 400-line limit. Adds focused tests; the full suite and
strict lint stay green.
