wind parsers.instructions.md

Parser conventions (lib/src/parser/)

Interface (every parser implements two methods)

class FooParser implements WindParserInterface {
  const FooParser();

  @override
  bool canParse(String className) =>
      className.startsWith('foo-') || className.startsWith('foo[');

  @override
  WindStyle parse(WindStyle styles, List<String>? classes, WindContext context) {
    if (classes == null) return styles;
    // ... iterate classes; return styles.copyWith(...)
    return styles;
  }
}

• canParse(String className) is O(1). Use startsWith() or a pre-compiled static final RegExp. No heavy logic.
• parse returns styles.copyWith(...) for every mutation. Never returns null. Never mutates the input list.
• The orchestrator's first-match-wins routing means canParse order matters: more specific prefixes register before more general ones. Registration is in lib/src/parser/wind_parser.dart's _parserMap (a const map of const parser instances).
• copyWith does not fabricate an empty BoxDecoration. Pass decoration: only when setting a real visual box property (color, border, radius, shadow, gradient, image), so the downstream decoration != null Container gate stays honest.

Last-class-wins semantics

Two safe patterns to implement "later token wins":

1. Reverse iteration with first-match-wins on each property: walk the class list backwards, set the property on the first match, break.
2. Forward iteration with explicit reset: like border_parser.dart — walk forward, on every match overwrite the property (and reset siblings to null where needed). Requires deliberate handling of partial directional properties.

Pick the pattern that fits the property family. Document the choice in a one-line comment at the iteration site when it might surprise a reader.

Arbitrary values precede theme lookups

For every property, parse the bracket-arbitrary form (p-[10px], bg-[#ff5733], text-[1.5rem]) BEFORE the theme-scale lookup. Arbitrary values are pixel-exact; theme keys are nominal: