chrono-node
Version:
A natural language date parser in Javascript
73 lines (65 loc) • 3.08 kB
text/typescript
import { ParsingContext } from "../../../chrono";
import { ParsingComponents } from "../../../results";
import { WEEKDAY_DICTIONARY } from "../constants";
import { matchAnyPattern } from "../../../utils/pattern";
import { AbstractParserWithWordBoundaryChecking } from "../../../common/parsers/AbstractParserWithWordBoundary";
import { createParsingComponentsAtWeekday } from "../../../common/calculation/weekdays";
import { Weekday } from "../../../types";
const PATTERN = new RegExp(
"(?:(?:\\,|\\(|\\()\\s*)?" +
"(?:on\\s*?)?" +
"(?:(this|last|past|next)\\s*)?" +
`(${matchAnyPattern(WEEKDAY_DICTIONARY)}|weekend|weekday)` +
"(?:\\s*(?:\\,|\\)|\\)))?" +
"(?:\\s*(this|last|past|next)\\s*week)?" +
"(?=\\W|$)",
"i"
);
const PREFIX_GROUP = 1;
const WEEKDAY_GROUP = 2;
const POSTFIX_GROUP = 3;
export default class ENWeekdayParser extends AbstractParserWithWordBoundaryChecking {
innerPattern(): RegExp {
return PATTERN;
}
innerExtract(context: ParsingContext, match: RegExpMatchArray): ParsingComponents | null {
const prefix = match[PREFIX_GROUP];
const postfix = match[POSTFIX_GROUP];
let modifierWord = prefix || postfix;
modifierWord = modifierWord || "";
modifierWord = modifierWord.toLowerCase();
let modifier = null;
if (modifierWord == "last" || modifierWord == "past") {
modifier = "last";
} else if (modifierWord == "next") {
modifier = "next";
} else if (modifierWord == "this") {
modifier = "this";
}
const weekday_word = match[WEEKDAY_GROUP].toLowerCase();
let weekday;
if (WEEKDAY_DICTIONARY[weekday_word] !== undefined) {
weekday = WEEKDAY_DICTIONARY[weekday_word];
} else if (weekday_word == "weekend") {
// This depends on what days are weekend setting, but typically:
// 'This/next weekend' means the coming Saturday, 'last weekend' means last Sunday.
weekday = modifier == "last" ? Weekday.SUNDAY : Weekday.SATURDAY;
} else if (weekday_word == "weekday") {
// In English, the "weekday" means any day of the week except weekend.
// This also depends on what days are weekend setting, but typically:
// - On weekend ref, this means the coming Monday or last Friday.
// - On weekday ref, this means the next/last working day.
const refWeekday = context.reference.getDateWithAdjustedTimezone().getDay();
if (refWeekday == Weekday.SUNDAY || refWeekday == Weekday.SATURDAY) {
weekday = modifier == "last" ? Weekday.FRIDAY : Weekday.MONDAY;
} else {
weekday = refWeekday - 1;
weekday = modifier == "last" ? weekday - 1 : weekday + 1;
weekday = (weekday % 5) + 1;
}
} else {
return null;
}
return createParsingComponentsAtWeekday(context.reference, weekday, modifier);
}
}