src/impl/regexParser.js
import { Util } from './util';
import { English } from './english';
import { FixedOffsetZone } from '../zones/fixedOffsetZone';
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 parsing
const isoTimeRegex = /(?:T(\d\d)(?::?(\d\d)(?::?(\d\d)(?:[.,](\d\d\d))?)?)?(?:(Z)|([+-]\d\d)(?::?(\d\d))?)?)?$/,
isoYmdRegex = /^([+-]\d{6}|\d{4})(?:-?(\d\d)(?:-?(\d\d))?)?/,
isoWeekRegex = /^(\d{4})-?W(\d\d)-?(\d)/,
isoOrdinalRegex = /^(\d{4})-?(\d{3})/,
extractISOWeekData = simpleParse('weekYear', 'weekNumber', 'weekDay'),
extractISOOrdinalData = simpleParse('year', 'ordinal');
function extractISOYmd(match, cursor) {
const item = {
year: parseInt(match[cursor]),
month: parseInt(match[cursor + 1]) || 1,
day: parseInt(match[cursor + 2]) || 1
};
return [item, null, cursor + 3];
}
function extractISOTime(match, cursor) {
const local = !match[cursor + 4] && !match[cursor + 5],
fullOffset = Util.signedOffset(match[cursor + 5], match[cursor + 6]),
item = {
hour: parseInt(match[cursor]) || 0,
minute: parseInt(match[cursor + 1]) || 0,
second: parseInt(match[cursor + 2]) || 0,
millisecond: parseInt(match[cursor + 3]) || 0
},
zone = local ? null : new FixedOffsetZone(fullOffset);
return [item, zone, cursor + 7];
}
// ISO duration parsing
const isoDuration = /^P(?:(\d+)Y)?(?:(\d+)M)?(?:(\d+)D)?(?:T(?:(\d+)H)?(?:(\d+)M)?(?:(\d+)S)?)?$/;
function extractISODuration(match) {
const [, yearStr, monthStr, dayStr, hourStr, minuteStr, secondStr] = match;
return {
year: parseInt(yearStr),
month: parseInt(monthStr),
day: parseInt(dayStr),
hour: parseInt(hourStr),
minute: parseInt(minuteStr),
second: parseInt(secondStr)
};
}
// 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 ? Util.untruncateYear(parseInt(yearStr)) : parseInt(yearStr),
month: 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 = Util.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 class RegexParser {
static parseISODate(s) {
return parse(
s,
[combineRegexes(isoYmdRegex, isoTimeRegex), combineExtractors(extractISOYmd, extractISOTime)],
[
combineRegexes(isoWeekRegex, isoTimeRegex),
combineExtractors(extractISOWeekData, extractISOTime)
],
[
combineRegexes(isoOrdinalRegex, isoTimeRegex),
combineExtractors(extractISOOrdinalData, extractISOTime)
]
);
}
static parseRFC2822Date(s) {
return parse(preprocessRFC2822(s), [rfc2822, extractRFC2822]);
}
static parseHTTPDate(s) {
return parse(
s,
[rfc1123, extractRFC1123Or850],
[rfc850, extractRFC1123Or850],
[ascii, extractASCII]
);
}
static parseISODuration(s) {
return parse(s, [isoDuration, extractISODuration]);
}
}