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							86 lines
						
					
					
						
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							86 lines
						
					
					
						
							3.0 KiB
						
					
					
				| // Copy-pasted from `PhoneNumberMatcher.js`.
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| 
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| import { PLUS_CHARS } from '../constants.js'
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| import { limit } from './util.js'
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| 
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| import {
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| 	isLatinLetter,
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| 	isInvalidPunctuationSymbol
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| } from './utf-8.js'
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| 
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| const OPENING_PARENS = '(\\[\uFF08\uFF3B'
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| const CLOSING_PARENS = ')\\]\uFF09\uFF3D'
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| const NON_PARENS = `[^${OPENING_PARENS}${CLOSING_PARENS}]`
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| 
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| export const LEAD_CLASS = `[${OPENING_PARENS}${PLUS_CHARS}]`
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| 
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| // Punctuation that may be at the start of a phone number - brackets and plus signs.
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| const LEAD_CLASS_LEADING = new RegExp('^' + LEAD_CLASS)
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| 
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| // Limit on the number of pairs of brackets in a phone number.
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| const BRACKET_PAIR_LIMIT = limit(0, 3)
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| 
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| /**
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|  * Pattern to check that brackets match. Opening brackets should be closed within a phone number.
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|  * This also checks that there is something inside the brackets. Having no brackets at all is also
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|  * fine.
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|  *
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|  * An opening bracket at the beginning may not be closed, but subsequent ones should be.  It's
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|  * also possible that the leading bracket was dropped, so we shouldn't be surprised if we see a
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|  * closing bracket first. We limit the sets of brackets in a phone number to four.
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|  */
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| const MATCHING_BRACKETS_ENTIRE = new RegExp
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| (
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| 	'^'
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| 	+ "(?:[" + OPENING_PARENS + "])?" + "(?:" + NON_PARENS + "+" + "[" + CLOSING_PARENS + "])?"
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| 	+ NON_PARENS + "+"
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| 	+ "(?:[" + OPENING_PARENS + "]" + NON_PARENS + "+[" + CLOSING_PARENS + "])" + BRACKET_PAIR_LIMIT
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| 	+ NON_PARENS + "*"
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| 	+ '$'
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| )
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| 
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| /**
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|  * Matches strings that look like publication pages. Example:
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|  * <pre>Computing Complete Answers to Queries in the Presence of Limited Access Patterns.
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|  * Chen Li. VLDB J. 12(3): 211-227 (2003).</pre>
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|  *
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|  * The string "211-227 (2003)" is not a telephone number.
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|  */
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| const PUB_PAGES = /\d{1,5}-+\d{1,5}\s{0,4}\(\d{1,4}/
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| 
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| export default function isValidCandidate(candidate, offset, text, leniency)
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| {
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| 	// Check the candidate doesn't contain any formatting
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| 	// which would indicate that it really isn't a phone number.
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| 	if (!MATCHING_BRACKETS_ENTIRE.test(candidate) || PUB_PAGES.test(candidate)) {
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| 		return
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| 	}
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| 
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| 	// If leniency is set to VALID or stricter, we also want to skip numbers that are surrounded
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| 	// by Latin alphabetic characters, to skip cases like abc8005001234 or 8005001234def.
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| 	if (leniency !== 'POSSIBLE')
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| 	{
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| 		// If the candidate is not at the start of the text,
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| 		// and does not start with phone-number punctuation,
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| 		// check the previous character.
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| 		if (offset > 0 && !LEAD_CLASS_LEADING.test(candidate))
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| 		{
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| 			const previousChar = text[offset - 1]
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| 			// We return null if it is a latin letter or an invalid punctuation symbol.
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| 			if (isInvalidPunctuationSymbol(previousChar) || isLatinLetter(previousChar)) {
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| 				return false
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| 			}
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| 		}
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| 
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| 		const lastCharIndex = offset + candidate.length
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| 		if (lastCharIndex < text.length)
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| 		{
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| 			const nextChar = text[lastCharIndex]
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| 			if (isInvalidPunctuationSymbol(nextChar) || isLatinLetter(nextChar)) {
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| 				return false
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| 			}
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| 		}
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| 	}
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| 
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| 	return true
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| } |