luxon
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Immutable date wrapper
287 lines (249 loc) • 8.72 kB
JavaScript
import { untruncateYear, signedOffset, parseMillis } from './util';
import * as English from './english';
import FixedOffsetZone from '../zones/fixedOffsetZone';
import IANAZone from '../zones/IANAZone';
/*
* This file handles parsing for well-specified formats. Here's how it works:
* Two things go into parsing: a regex to match with and an extractor to take apart the groups in the match.
* An extractor is just a function that takes a regex match array and returns a { year: ..., month: ... } object
* parse() does the work of executing the regex and applying the extractor. It takes multiple regex/extractor pairs to try in sequence.
* Extractors can take a "cursor" representing the offset in the match to look at. This makes it easy to combine extractors.
* combineExtractors() does the work of combining them, keeping track of the cursor through multiple extractions.
* Some extractions are super dumb and simpleParse and fromStrings help DRY them.
*/
function combineRegexes(...regexes) {
const full = regexes.reduce((f, r) => f + r.source, '');
return RegExp(`^${full}$`);
}
function combineExtractors(...extractors) {
return m =>
extractors
.reduce(
([mergedVals, mergedZone, cursor], ex) => {
const [val, zone, next] = ex(m, cursor);
return [Object.assign(mergedVals, val), mergedZone || zone, next];
},
[{}, null, 1]
)
.slice(0, 2);
}
function parse(s, ...patterns) {
if (s == null) {
return [null, null];
}
for (const [regex, extractor] of patterns) {
const m = regex.exec(s);
if (m) {
return extractor(m);
}
}
return [null, null];
}
function simpleParse(...keys) {
return (match, cursor) => {
const ret = {};
let i;
for (i = 0; i < keys.length; i++) {
ret[keys[i]] = parseInt(match[cursor + i]);
}
return [ret, null, cursor + i];
};
}
// ISO and SQL parsing
const offsetRegex = /(?:(Z)|([+-]\d\d)(?::?(\d\d))?)/,
isoTimeBaseRegex = /(\d\d)(?::?(\d\d)(?::?(\d\d)(?:[.,](\d{1,9}))?)?)?/,
isoTimeRegex = RegExp(`${isoTimeBaseRegex.source}${offsetRegex.source}?`),
isoTimeExtensionRegex = RegExp(`(?:T${isoTimeRegex.source})?`),
isoYmdRegex = /([+-]\d{6}|\d{4})(?:-?(\d\d)(?:-?(\d\d))?)?/,
isoWeekRegex = /(\d{4})-?W(\d\d)-?(\d)/,
isoOrdinalRegex = /(\d{4})-?(\d{3})/,
extractISOWeekData = simpleParse('weekYear', 'weekNumber', 'weekDay'),
extractISOOrdinalData = simpleParse('year', 'ordinal'),
sqlYmdRegex = /(\d{4})-(\d\d)-(\d\d)/, // dumbed-down version of the ISO one
sqlTimeRegex = RegExp(
`${isoTimeBaseRegex.source} ?(?:${offsetRegex.source}|([a-zA-Z_]{1,256}/[a-zA-Z_]{1,256}))?`
),
sqlTimeExtensionRegex = RegExp(`(?: ${sqlTimeRegex.source})?`);
function extractISOYmd(match, cursor) {
const item = {
year: parseInt(match[cursor]),
month: parseInt(match[cursor + 1]) || 1,
day: parseInt(match[cursor + 2]) || 1
};
return [item, null, cursor + 3];
}
function extractISOTime(match, cursor) {
const item = {
hour: parseInt(match[cursor]) || 0,
minute: parseInt(match[cursor + 1]) || 0,
second: parseInt(match[cursor + 2]) || 0,
millisecond: parseMillis(match[cursor + 3])
};
return [item, null, cursor + 4];
}
function extractISOOffset(match, cursor) {
const local = !match[cursor] && !match[cursor + 1],
fullOffset = signedOffset(match[cursor + 1], match[cursor + 2]),
zone = local ? null : FixedOffsetZone.instance(fullOffset);
return [{}, zone, cursor + 3];
}
function extractIANAZone(match, cursor) {
const zone = match[cursor] ? new IANAZone(match[cursor]) : null;
return [{}, zone, cursor + 1];
}
// ISO duration parsing
const isoDuration = /^P(?:(?:(\d{1,9})Y)?(?:(\d{1,9})M)?(?:(\d{1,9})D)?(?:T(?:(\d{1,9})H)?(?:(\d{1,9})M)?(?:(\d{1,9})(?:[.,](\d{1,9}))?S)?)?|(\d{1,9})W)$/;
function extractISODuration(match) {
const [
,
yearStr,
monthStr,
dayStr,
hourStr,
minuteStr,
secondStr,
millisecondsStr,
weekStr
] = match;
return [
{
years: parseInt(yearStr),
months: parseInt(monthStr),
weeks: parseInt(weekStr),
days: parseInt(dayStr),
hours: parseInt(hourStr),
minutes: parseInt(minuteStr),
seconds: parseInt(secondStr),
milliseconds: parseMillis(millisecondsStr)
}
];
}
// These are a little braindead. EDT *should* tell us that we're in, say, America/New_York
// and not just that we're in -240 *right now*. But since I don't think these are used that often
// I'm just going to ignore that
const obsOffsets = {
GMT: 0,
EDT: -4 * 60,
EST: -5 * 60,
CDT: -5 * 60,
CST: -6 * 60,
MDT: -6 * 60,
MST: -7 * 60,
PDT: -7 * 60,
PST: -8 * 60
};
function fromStrings(weekdayStr, yearStr, monthStr, dayStr, hourStr, minuteStr, secondStr) {
const result = {
year: yearStr.length === 2 ? untruncateYear(parseInt(yearStr)) : parseInt(yearStr),
month:
monthStr.length === 2 ? parseInt(monthStr, 10) : English.monthsShort.indexOf(monthStr) + 1,
day: parseInt(dayStr),
hour: parseInt(hourStr),
minute: parseInt(minuteStr)
};
if (secondStr) result.second = parseInt(secondStr);
if (weekdayStr) {
result.weekday =
weekdayStr.length > 3
? English.weekdaysLong.indexOf(weekdayStr) + 1
: English.weekdaysShort.indexOf(weekdayStr) + 1;
}
return result;
}
// RFC 2822/5322
const rfc2822 = /^(?:(Mon|Tue|Wed|Thu|Fri|Sat|Sun),\s)?(\d{1,2})\s(Jan|Feb|Mar|Apr|May|Jun|Jul|Aug|Sep|Oct|Nov|Dec)\s(\d{2,4})\s(\d\d):(\d\d)(?::(\d\d))?\s(?:(UT|GMT|[ECMP][SD]T)|([Zz])|(?:([+-]\d\d)(\d\d)))$/;
function extractRFC2822(match) {
const [
,
weekdayStr,
dayStr,
monthStr,
yearStr,
hourStr,
minuteStr,
secondStr,
obsOffset,
milOffset,
offHourStr,
offMinuteStr
] = match,
result = fromStrings(weekdayStr, yearStr, monthStr, dayStr, hourStr, minuteStr, secondStr);
let offset;
if (obsOffset) {
offset = obsOffsets[obsOffset];
} else if (milOffset) {
offset = 0;
} else {
offset = signedOffset(offHourStr, offMinuteStr);
}
return [result, new FixedOffsetZone(offset)];
}
function preprocessRFC2822(s) {
// Remove comments and folding whitespace and replace multiple-spaces with a single space
return s
.replace(/\([^)]*\)|[\n\t]/g, ' ')
.replace(/(\s\s+)/g, ' ')
.trim();
}
// http date
const rfc1123 = /^(Mon|Tue|Wed|Thu|Fri|Sat|Sun), (\d\d) (Jan|Feb|Mar|Apr|May|Jun|Jul|Aug|Sep|Oct|Nov|Dec) (\d{4}) (\d\d):(\d\d):(\d\d) GMT$/,
rfc850 = /^(Monday|Tuesday|Wedsday|Thursday|Friday|Saturday|Sunday), (\d\d)-(Jan|Feb|Mar|Apr|May|Jun|Jul|Aug|Sep|Oct|Nov|Dec)-(\d\d) (\d\d):(\d\d):(\d\d) GMT$/,
ascii = /^(Mon|Tue|Wed|Thu|Fri|Sat|Sun) (Jan|Feb|Mar|Apr|May|Jun|Jul|Aug|Sep|Oct|Nov|Dec) ( \d|\d\d) (\d\d):(\d\d):(\d\d) (\d{4})$/;
function extractRFC1123Or850(match) {
const [, weekdayStr, dayStr, monthStr, yearStr, hourStr, minuteStr, secondStr] = match,
result = fromStrings(weekdayStr, yearStr, monthStr, dayStr, hourStr, minuteStr, secondStr);
return [result, FixedOffsetZone.utcInstance];
}
function extractASCII(match) {
const [, weekdayStr, monthStr, dayStr, hourStr, minuteStr, secondStr, yearStr] = match,
result = fromStrings(weekdayStr, yearStr, monthStr, dayStr, hourStr, minuteStr, secondStr);
return [result, FixedOffsetZone.utcInstance];
}
/**
* @private
*/
export function parseISODate(s) {
return parse(
s,
[
combineRegexes(isoYmdRegex, isoTimeExtensionRegex),
combineExtractors(extractISOYmd, extractISOTime, extractISOOffset)
],
[
combineRegexes(isoWeekRegex, isoTimeExtensionRegex),
combineExtractors(extractISOWeekData, extractISOTime, extractISOOffset)
],
[
combineRegexes(isoOrdinalRegex, isoTimeExtensionRegex),
combineExtractors(extractISOOrdinalData, extractISOTime)
],
[combineRegexes(isoTimeRegex), combineExtractors(extractISOTime, extractISOOffset)]
);
}
export function parseRFC2822Date(s) {
return parse(preprocessRFC2822(s), [rfc2822, extractRFC2822]);
}
export function parseHTTPDate(s) {
return parse(
s,
[rfc1123, extractRFC1123Or850],
[rfc850, extractRFC1123Or850],
[ascii, extractASCII]
);
}
export function parseISODuration(s) {
return parse(s, [isoDuration, extractISODuration]);
}
export function parseSQL(s) {
return parse(
s,
[
combineRegexes(sqlYmdRegex, sqlTimeExtensionRegex),
combineExtractors(extractISOYmd, extractISOTime, extractISOOffset, extractIANAZone)
],
[
combineRegexes(sqlTimeRegex),
combineExtractors(extractISOTime, extractISOOffset, extractIANAZone)
]
);
}