Group @testable imports at the bottom, per public/rules-swift's swiftformat. A
behavior-preserving import-ordering reformat across 252 files (mostly tests).
--trailingclosures was deliberately not adopted (cosmetic, and swiftformat flags
it as caution-worthy).
Slice 3 of #92. The DTD validator's imperative walk becomes declared Validation
values over a DTDSchema document:
- DTDSchema is now just the schema (content models + attribute declarations) and
serves as the rules' Document context; its validate/walk methods are gone.
- contentModel and attributeDeclarations are Validation<Element, DTDSchema>, so
every content-model and attribute violation is now located by coding path
("... at path: r/a"). undeclaredElement is added only in strict mode.
- identifierIntegrity is a Validation<Node, DTDSchema> gated to the root, doing
the document-wide ID-uniqueness and IDREF-resolution checks in one pass.
- DTD.validator(strict:) assembles the rule set; validateAgainstInternalDTD runs
it and returns [ValidationError] instead of [Issue].
A new test pins the located result. Schema (XSD) and Schematron validators still
use Issue and migrate in the following slices.
Surface <!ATTLIST> declarations from the parser and validate attributes against
them. Reimplemented from the DTD attribute-list spec; no upstream code copied.
- DocumentType gains attributeLists (raw ATTLIST bodies per element); the
DoctypeScanner captures them and the EventReader plumbs them through.
- AttributeListParser parses a body into AttributeDeclaration values
(AttributeType: cdata or enumeration; AttributeDefault: required/implied/
fixed/value).
- DTDSchema now checks #REQUIRED presence, #FIXED value match (when present),
and enumerated-value membership, in addition to content models.
- Tokenized types (ID/IDREF/NMTOKEN) parse but are not yet value-enforced.
- 5 attribute tests; 75 total.
