echogarden/src/utilities/StringUtilities.ts

An easy-to-use speech toolset. Includes tools for synthesis, recognition, alignment, speech translation, language detection, source separation and more.

import { TypedArray } from '../typings/TypedArray.js'

export function includesAnyOf(str: string, substrings: string[]) {
	return indexOfAnyOf(str, substrings) >= 0
}

export function indexOfAnyOf(str: string, substrings: string[]) {
	for (const substring of substrings) {
		const index = str.indexOf(substring)

		if (index >= 0) {
			return index
		}
	}

	return -1
}

export function startsWithAnyOf(str: string, prefixes: string[]) {
	for (const prefix of prefixes) {
		if (str.startsWith(prefix)) {
			return true
		}
	}

	return false
}

export function formatHMS(timeHMS: { hours: number, minutes: number, seconds: number, milliseconds: number }, decimalSeparator = '.') {
	return `${formatIntegerWithLeadingZeros(timeHMS.hours, 2)}:${formatIntegerWithLeadingZeros(timeHMS.minutes, 2)}:${formatIntegerWithLeadingZeros(timeHMS.seconds, 2)}${decimalSeparator}${formatIntegerWithLeadingZeros(timeHMS.milliseconds, 3)}`
}

export function formatMS(timeMS: { minutes: number, seconds: number, milliseconds: number }, decimalSeparator = '.') {
	return `${formatIntegerWithLeadingZeros(timeMS.minutes, 2)}:${formatIntegerWithLeadingZeros(timeMS.seconds, 2)}${decimalSeparator}${formatIntegerWithLeadingZeros(timeMS.milliseconds, 3)}`
}

export function formatIntegerWithLeadingZeros(num: number, minDigitCount: number) {
	num = Math.floor(num)

	let numAsString = `${num}`

	while (numAsString.length < minDigitCount) {
		numAsString = `0${numAsString}`
	}

	return numAsString
}

export function formatListWithQuotedElements(strings: string[], quoteSymbol = `'`) {
	return strings.map(str => `${quoteSymbol}${str}${quoteSymbol}`).join(', ')
}

export function getUTF32Chars(str: string) {
	const utf32chars: string[] = []
	const utf16To32Mapping: number[] = []

	let utf32Index = 0

	for (const utf32char of str) {
		utf32chars.push(utf32char)

		for (let i = 0; i < utf32char.length; i++) {
			utf16To32Mapping.push(utf32Index)
		}

		utf32Index += 1
	}

	utf16To32Mapping.push(utf32Index)

	return { utf32chars, utf16To32Mapping }
}

export function containsInvalidCodepoint(str: string) {
	for (const char of str) {
		if (char.codePointAt(0) === 65533) {
			return true
		}
	}

	return false
}

export function splitAndPreserveSeparators(text: string, separatorRegex: RegExp): string[] {
	if (!separatorRegex.flags.includes('g')) {
		throw new Error('Separator regular expression must have a global flag')
	}

	// Use the match method to find all matches for the separators
	const matches = text.match(separatorRegex)

	// If no matches are found, return the original text as a single element array
	if (!matches) {
		return [text]
	}

	// Initialize the result array
	const result: string[] = []

	// Initialize the start position
	let lastIndex = 0

	// Iterate through the matches
	matches.forEach(match => {
		// Get the index of the current match
		const matchIndex = text.indexOf(match, lastIndex)

		// Add the substring before the match to the result, joined with the match itself
		result.push(text.substring(lastIndex, matchIndex) + match)

		// Update the last index to the end of the current match
		lastIndex = matchIndex + match.length
	})

	// Add the remaining substring after the last match to the result
	{
		const remainingText = text.substring(lastIndex)

		if (remainingText.length > 0) {
			result.push(remainingText)
		}
	}

	return result
}

export function getTokenRepetitionScore(tokens: string[] | number[]) {
	const maxCycleLength = Math.floor(tokens.length / 2)

	const matchLengthForCycleLength: number[] = [0]

	for (let cycleLength = 1; cycleLength <= maxCycleLength; cycleLength++) {
		let matchCount = 0

		for (let leftIndex = cycleLength; leftIndex < tokens.length; leftIndex++) {
			const referenceIndex = leftIndex - cycleLength

			if (tokens[leftIndex] !== tokens[referenceIndex]) {
				break
			}

			matchCount += 1
		}

		const score = matchCount

		matchLengthForCycleLength.push(score)
	}

	let longestMatchLength = -Infinity
	let longestCycleRepetitionCount = -Infinity

	for (let i = 1; i <= matchLengthForCycleLength.length; i++) {
		const matchLength = matchLengthForCycleLength[i]

		if (matchLength > longestMatchLength) {
			longestMatchLength = matchLength
		}

		const cycleCount = (matchLength / i) + 1

		if (cycleCount > longestCycleRepetitionCount) {
			longestCycleRepetitionCount = cycleCount
		}
	}

	return { longestMatchLength, longestCycleRepetitionCount }
}

export async function convertHtmlToText(html: string) {
	const { htmlToText } = await import('html-to-text')

	const text = htmlToText(html, {
		wordwrap: false,

		selectors: [
			{ selector: 'a', options: { ignoreHref: true } },
			{ selector: 'img', format: 'skip' },
			{ selector: 'h1', options: { uppercase: false } },
			{ selector: 'h2', options: { uppercase: false } },
			{ selector: 'h3', options: { uppercase: false } },
			{ selector: 'h4', options: { uppercase: false } },
			{ selector: 'table', options: { uppercaseHeaderCells: false } }
		]
	})

	return text || ''
}

export function substituteCharactersUsingLookup(text: string, substitutionLookup: Record<string, string>) {
	let resultText = ''

	for (const char of text) {
		const substitution = substitutionLookup[char]

		if (substitution !== undefined) {
			resultText += substitution
		} else {
			resultText += char
		}
	}

	return resultText
}

export function substituteStringUsingLookup(text: string, substitutionLookup: Record<string, string>) {
	const substitution = substitutionLookup[text]

	if (substitution !== undefined) {
		return substitution
	} else {
		return text
	}
}