dewbead library

Parse dewdrop output lines (dewbead) into structured calendar events.

Two stages keep NOW isolated: parse (NOW-free syntax) and resolve (NOW-based absolutization). parseDewbead runs both.

Classes

AbsoluteDate: (yyyy-)mm-dd. year null -> inferred in resolve.
ClockTime: HH:MM — an absolute 24-hour wall-clock time.
DatePart: The date component of a datetime — NOW-free. The anchor is the offset unit.
Datetime: date_part [/time_part]. time null -> all-day.
DatetimeEndpoint: ~t+2/02:00 — a full end datetime (date always explicit).
Delta: A signed relative amount, e.g. +85m -> Delta(85, minute).
DewbeadAst: Pure syntactic parse of one dewbead record (NOW-free).
DurationEndpoint: ~+90m — duration added to start. First char of the token is +/-.
EndpointSpec: The ~ endpoint token (event only) — NOW-free.
MonthDate: mo [±N] . D — day dom of the month N months from now.
ParsedEvent: A fully resolved calendar item.
ParseResult: Result of parsing a document: successfully events plus per-record errors. A document of N yields both lists empty.
RecordError: One failed record from a parse: reason and the raw segment rawInput.
RelativeTime: n ±N… — added to NOW. The parser guarantees the owning date_part is TodayDate(0) when the time is a RelativeTime; the AST does not re-check.
TimePart: The optional time component after /. Absence means all-day.
TodayDate: t [±N] — today + N days. offset 0 means today.
WeekDate: w [±N] . WD — the weekday of the week N weeks from now (Monday start).

parse(String document) → ParseAstResult: Stage 1: parse a dewbead document into ASTs without touching NOW.
parseDewbead(String document, DateTime now, {String? sourceText}) → ParseResult: Parse and resolve a dewbead document in one call.
resolve(DewbeadAst ast, DateTime now, {String? sourceText}) → ParsedEvent: Stage 2: resolve a DewbeadAst against now into a ParsedEvent.

ParseAstResult = ({List<DewbeadAst> asts, List<RecordError> errors}): Result of stage-1 parse: successfully parsed asts plus per-record errors, preserving partial-failure semantics across ;;.