API reference¶

Every method lives on a Cosmo instance (or its static factories). Names are camelCase in PHP/JavaScript/Java and snake_case in Python (splitWords → split_words, timeZoneName → time_zone_name, …). Java has no keyword/optional arguments, so optional parameters become overloads, and the options bags are Map<String, Object> with the same camelCase keys as JS.

Width arguments are none · short · medium · long · full. Legend: ✅ available · ❌ not available · ⚠️ partial / different shape. See Platform notes for the why.

Construction¶

Signature	PHP	JS	Py	Java
`new Cosmo(locale?, modifiers?)`	✅	✅	✅	✅
`fromSubtags(subtags, modifiers?)`	✅	✅	✅	✅
`fromAcceptLanguage(header, modifiers?)`	✅	✅	✅	✅
`fromAcceptLanguage(header, supported, …)` — CLDR-negotiating	❌	❌	✅	✅

Modifiers: calendar, currency, timeZone.

Locale metadata¶

Method	Purpose	PHP	JS	Py	Java
`language(code?)`	localised language name	✅	✅	✅	✅
`country(code?)`	localised country/region name	✅	✅	✅	✅
`script(code?)`	localised script name	✅	✅	✅	✅
`calendar(code)`	localised calendar name	✅	✅	✅	✅
`direction(lang?)`	`"rtl"` / `"ltr"`	✅	✅	✅	✅
`flag(country?)`	region → emoji flag	✅	✅	✅	✅
`currency(code?, symbol?, strict?)`	currency name or symbol	✅	⚠️	✅	✅
`displayName(type, code)`	generic display-name lookup	✅	✅	✅	✅
`supportedValues(key)`	enumerate supported calendars/zones/…	⚠️	✅	⚠️	✅
`addLikelySubtags()`	maximise (`en` → `en-Latn-US`)	❌	✅	✅	✅
`removeLikelySubtags()`	minimise	❌	✅	✅	✅

Numbers & money¶

Method	Purpose	PHP	JS	Py	Java
`number(value, options?)`	locale decimal format	✅	✅	✅	✅
`percentage(value, precision?, options?)`	fraction → percent	✅	✅	✅	✅
`money(value, code?, …)`	currency amount	✅	⚠️	✅	✅
`unit(category, unit, value, width?)`	measurement + unit	✅	✅	✅	✅
`symbol(name)`	named number symbol	✅	⚠️	✅	✅
`scientific(value)`	scientific notation	✅	✅	✅	✅
`compact(value, width?)`	compact notation (`1.2K`)	✅	✅	✅	✅
`ordinal(number)`	ordinal text (`"2nd"`)	✅	❌	✅	✅
`spellout(number)`	spelled-out number	✅	❌	✅	✅

number / percentage / money accept an options bag. The portable options — minimumIntegerDigits, minimumFractionDigits, maximumFractionDigits, minimumSignificantDigits, maximumSignificantDigits, roundingMode, roundingIncrement, useGrouping — behave identically in all four ports, with a halfExpand rounding default everywhere. The full Intl.NumberFormat surface is also accepted, but the extras (signDisplay, trailingZeroDisplay, roundingPriority, notation, compactDisplay) take effect in the JS port only — the other ports' ICU formatters have no equivalent and silently ignore them (use the dedicated compact() / scientific() methods there instead).

Dates & times¶

Method	Purpose	PHP	JS	Py	Java
`moment(value, dateWidth?, timeWidth?, calendar?)`	date + time	✅	✅	✅	✅
`date(value, width?)`	date only	✅	✅	✅	✅
`time(value, width?)`	time only	✅	✅	✅	✅
`duration(seconds \\| parts, withWords?)`	undirected span (scalar seconds or a unit breakdown)	✅	✅	✅	✅
`timeZoneName(style?)`	time-zone display name	✅	✅	✅	✅
`monthNames(width?)`	localised month names	✅	✅	✅	✅
`weekdayNames(width?)`	localised weekday names (Sun-first)	✅	✅	✅	✅
`weekInfo()`	first day / weekend / minimal days	✅	✅	⚠️	✅
`formatMoment(value, pattern, calendar?)`	raw ICU pattern	✅	❌	✅	✅
`dateRange(start, end, dateWidth?, timeWidth?)`	date range	⚠️	✅	✅	✅

weekInfo() omits the weekend in Python; dateRange() is short/medium only in PHP. See Platform notes.

Collation & text¶

Method	Purpose	PHP	JS	Py	Java
`compare(a, b, options?)`	locale comparison	✅	✅	✅	✅
`sort(items, key?, options?)`	locale sort	✅	✅	✅	✅
`contains(haystack, needle, sensitivity?, options?)`	collation-aware search	✅	✅	✅	✅
`splitWords(text)`	word segmentation	✅	✅	✅	✅
`splitSentences(text)`	sentence segmentation	✅	✅	✅	✅
`splitGraphemes(text)`	grapheme-cluster segmentation	✅	✅	✅	✅
`ellipsize(text, max, ellipsis?)`	grapheme-safe truncation	✅	✅	✅	✅
`upper(text)` / `lower(text)`	locale case mapping	✅	✅	✅	✅

compare / sort / contains accept collation tailoring via options (numeric, caseFirst). The key accessor on sort is Python-only; Java passes the collator as a Comparator.

Messages, plurals & lists¶

Method	Purpose	PHP	JS	Py	Java
`message(pattern, args?)`	ICU MessageFormat	✅	⚠️	✅	✅
`pluralCategory(value, ordinal?)`	LDML plural category	✅	✅	✅	✅
`join(items, type?, width?)`	locale list join	✅	✅	✅	✅
`quote(text)`	locale quotation marks	✅	❌	✅	✅

JS message() is a hand-written subset (arguments, number, plural, select); PHP, Python, and Java use full ICU MessageFormat (named and positional args).

Ranges & relative time¶

Method	Purpose	PHP	JS	Py	Java
`numberRange(start, end)`	numeric range	✅	✅	✅	✅
`moneyRange(start, end, code?)`	currency range	⚠️	✅	✅	✅
`relativeDuration(amount, unit, numeric?)`	directed duration	✅	✅	⚠️	✅
`relativeDurationBetween(target, reference?, numeric?)`	relative between moments	✅	✅	✅	✅

PHP reconstructs these from CLDR data (so moneyRange is approximate); Python's relativeDuration(numeric="auto") falls back to the numeric form.

Transliteration & spoof detection¶

Method	Purpose	PHP	JS	Py	Java
`transliterate(text, id)`	ICU `Transliterator` transform	✅	❌	✅	✅
`romanize(text)`	to Latin/ASCII (`"Any-Latin; Latin-ASCII"`)	✅	❌	✅	✅
`confusable(a, b)`	UTS #39 confusable-skeleton match	✅	❌	✅	✅
`suspicious(text)`	flag mixed-script / spoof-prone text	✅	❌	✅	✅

Locale-aware parsing (inverse formatters)¶

Method	Purpose	PHP	JS	Py	Java
`parseNumber(text)`	locale string → number	✅	❌	✅	✅
`parseMoney(text)`	→ amount + currency	✅	❌	✅	✅
`parseDate(text, width?)`	inverse of `date()`	✅	❌	✅	✅
`parseMoment(text, pattern)`	inverse of `formatMoment()`	✅	❌	✅	✅

Intl is format-only, so the whole parsing family is JS-blocked.

Negotiation, indexing & names¶

Method	Purpose	PHP	JS	Py	Java
`bestMatch(supported)`	CLDR-distance pick of your locales	❌	❌	✅	✅
`indexBuckets(names)`	`AlphabeticIndex` section headers	❌	❌	✅	✅
`personName(fields, length?, formality?)`	locale-correct person names	❌	❌	❌	✅

Raw ICU services¶

Method	Purpose	PHP	JS	Py	Java
`get(bundle, ...path)`	raw `ResourceBundle` lookup	✅	❌	✅	✅