🎯 Use case
This file lives under “utils/”, which covers cross-cutting helpers (shell, tempfiles, settings, messages, process input, …). On the API surface it exposes getGraphemeSegmenter, firstGrapheme, lastGrapheme, getWordSegmenter, and getRelativeTimeFormat (and more) — mainly functions, hooks, or classes. What the file header says: Shared Intl object instances with lazy initialization. Intl constructors are expensive (~0.05-0.1ms each), so we cache instances for reuse across the codebase instead of creating new ones each time. Lazy initialization ensures we only pay the cost when actually needed.
Generated from folder role, exports, dependency roots, and inline comments — not hand-reviewed for every path.
🧠 Inline summary
Shared Intl object instances with lazy initialization. Intl constructors are expensive (~0.05-0.1ms each), so we cache instances for reuse across the codebase instead of creating new ones each time. Lazy initialization ensures we only pay the cost when actually needed.
📤 Exports (heuristic)
getGraphemeSegmenterfirstGraphemelastGraphemegetWordSegmentergetRelativeTimeFormatgetTimeZonegetSystemLocaleLanguage
🖥️ Source preview
/**
* Shared Intl object instances with lazy initialization.
*
* Intl constructors are expensive (~0.05-0.1ms each), so we cache instances
* for reuse across the codebase instead of creating new ones each time.
* Lazy initialization ensures we only pay the cost when actually needed.
*/
// Segmenters for Unicode text processing (lazily initialized)
let graphemeSegmenter: Intl.Segmenter | null = null
let wordSegmenter: Intl.Segmenter | null = null
export function getGraphemeSegmenter(): Intl.Segmenter {
if (!graphemeSegmenter) {
graphemeSegmenter = new Intl.Segmenter(undefined, {
granularity: 'grapheme',
})
}
return graphemeSegmenter
}
/**
* Extract the first grapheme cluster from a string.
* Returns '' for empty strings.
*/
export function firstGrapheme(text: string): string {
if (!text) return ''
const segments = getGraphemeSegmenter().segment(text)
const first = segments[Symbol.iterator]().next().value
return first?.segment ?? ''
}
/**
* Extract the last grapheme cluster from a string.
* Returns '' for empty strings.
*/
export function lastGrapheme(text: string): string {
if (!text) return ''
let last = ''
for (const { segment } of getGraphemeSegmenter().segment(text)) {
last = segment
}
return last
}
export function getWordSegmenter(): Intl.Segmenter {
if (!wordSegmenter) {
wordSegmenter = new Intl.Segmenter(undefined, { granularity: 'word' })
}
return wordSegmenter
}
// RelativeTimeFormat cache (keyed by style:numeric)
const rtfCache = new Map<string, Intl.RelativeTimeFormat>()
export function getRelativeTimeFormat(
style: 'long' | 'short' | 'narrow',
numeric: 'always' | 'auto',
): Intl.RelativeTimeFormat {
const key = `${style}:${numeric}`
let rtf = rtfCache.get(key)
if (!rtf) {
rtf = new Intl.RelativeTimeFormat('en', { style, numeric })
rtfCache.set(key, rtf)
}
return rtf
}
// Timezone is constant for the process lifetime
let cachedTimeZone: string | null = null
export function getTimeZone(): string {
if (!cachedTimeZone) {
cachedTimeZone = Intl.DateTimeFormat().resolvedOptions().timeZone
}
return cachedTimeZone
}
// System locale language subtag (e.g. 'en', 'ja') is constant for the process
// lifetime. null = not yet computed; undefined = computed but unavailable (so
// a stripped-ICU environment fails once instead of retrying on every call).
let cachedSystemLocaleLanguage: string | undefined | null = null
export function getSystemLocaleLanguage(): string | undefined {
if (cachedSystemLocaleLanguage === null) {
try {
const locale = Intl.DateTimeFormat().resolvedOptions().locale
cachedSystemLocaleLanguage = new Intl.Locale(locale).language
} catch {
cachedSystemLocaleLanguage = undefined
}
}
return cachedSystemLocaleLanguage
}