chrono-node/src/locales/ru/parsers/RUTimeUnitAgoFormatParser.ts

A natural language date parser in Javascript

import { ParsingContext } from "../../../chrono";
import { parseTimeUnits, TIME_UNITS_PATTERN } from "../constants";
import { ParsingComponents } from "../../../results";
import { reverseTimeUnits } from "../../../utils/timeunits";
import { AbstractParserWithLeftBoundaryChecking } from "./AbstractParserWithWordBoundaryChecking";

export default class RUTimeUnitAgoFormatParser extends AbstractParserWithLeftBoundaryChecking {
    innerPatternString(context: ParsingContext): string {
        return `(${TIME_UNITS_PATTERN})\\s{0,5}назад(?=(?:\\W|$))`;
    }

    innerExtract(context: ParsingContext, match: RegExpMatchArray) {
        const timeUnits = parseTimeUnits(match[1]);
        const outputTimeUnits = reverseTimeUnits(timeUnits);

        return ParsingComponents.createRelativeFromReference(context.reference, outputTimeUnits);
    }
}