Exemple #1
0
func (s *CJKWidthFilter) Filter(input analysis.TokenStream) analysis.TokenStream {
	for _, token := range input {
		runeCount := utf8.RuneCount(token.Term)
		runes := bytes.Runes(token.Term)
		for i := 0; i < runeCount; i++ {
			ch := runes[i]
			if ch >= 0xFF01 && ch <= 0xFF5E {
				// fullwidth ASCII variants
				runes[i] -= 0xFEE0
			} else if ch >= 0xFF65 && ch <= 0xFF9F {
				// halfwidth Katakana variants
				if (ch == 0xFF9E || ch == 0xFF9F) && i > 0 && combine(runes, i, ch) {
					runes = analysis.DeleteRune(runes, i)
					i--
					runeCount = len(runes)
				} else {
					runes[i] = kanaNorm[ch-0xFF65]
				}
			}
		}
		token.Term = analysis.BuildTermFromRunes(runes)
	}

	return input
}
Exemple #2
0
func (s *NgramFilter) Filter(input analysis.TokenStream) analysis.TokenStream {
	rv := make(analysis.TokenStream, 0, len(input))

	for _, token := range input {
		runeCount := utf8.RuneCount(token.Term)
		runes := bytes.Runes(token.Term)
		for i := 0; i < runeCount; i++ {
			// index of the starting rune for this token
			for ngramSize := s.minLength; ngramSize <= s.maxLength; ngramSize++ {
				// build an ngram of this size starting at i
				if i+ngramSize <= runeCount {
					ngramTerm := analysis.BuildTermFromRunes(runes[i : i+ngramSize])
					token := analysis.Token{
						Position: token.Position,
						Start:    token.Start,
						End:      token.End,
						Type:     token.Type,
						Term:     ngramTerm,
					}
					rv = append(rv, &token)
				}
			}
		}
	}

	return rv
}
Exemple #3
0
func (s *FrenchLightStemmerFilter) Filter(input analysis.TokenStream) analysis.TokenStream {
	for _, token := range input {
		runes := bytes.Runes(token.Term)
		runes = stem(runes)
		token.Term = analysis.BuildTermFromRunes(runes)
	}
	return input
}
Exemple #4
0
func (s *IndicNormalizeFilter) Filter(input analysis.TokenStream) analysis.TokenStream {
	for _, token := range input {
		runes := bytes.Runes(token.Term)
		runes = normalize(runes)
		token.Term = analysis.BuildTermFromRunes(runes)
	}
	return input
}
Exemple #5
0
func (s *PorterStemmer) Filter(input analysis.TokenStream) analysis.TokenStream {
	for _, token := range input {
		// if it is not a protected keyword, stem it
		if !token.KeyWord {
			termRunes := bytes.Runes(token.Term)
			stemmedRunes := porterstemmer.StemWithoutLowerCasing(termRunes)
			token.Term = analysis.BuildTermFromRunes(stemmedRunes)
		}
	}
	return input
}
Exemple #6
0
func stem(input []byte) []byte {
	runes := bytes.Runes(input)
	// Strip a single prefix.
	for _, p := range prefixes {
		if canStemPrefix(runes, p) {
			runes = runes[len(p):]
			break
		}
	}
	// Strip off multiple suffixes, in their order in the suffixes array.
	for _, s := range suffixes {
		if canStemSuffix(runes, s) {
			runes = runes[:len(runes)-len(s)]
		}
	}
	return analysis.BuildTermFromRunes(runes)
}
Exemple #7
0
func normalize(input []byte) []byte {
	runes := bytes.Runes(input)
	for i := 0; i < len(runes); i++ {
		switch runes[i] {
		case AlefMadda, AlefHamzaAbove, AlefHamzaBelow:
			runes[i] = Alef
		case DotlessYeh:
			runes[i] = Yeh
		case TehMarbuta:
			runes[i] = Heh
		case Tatweel, Kasratan, Dammatan, Fathatan, Fatha, Damma, Kasra, Shadda, Sukun:
			runes = analysis.DeleteRune(runes, i)
			i--
		}
	}
	return analysis.BuildTermFromRunes(runes)
}
Exemple #8
0
func normalize(input []byte) []byte {
	runes := bytes.Runes(input)
	for i := 0; i < len(runes); i++ {
		switch runes[i] {
		case FarsiYeh, YehBarree:
			runes[i] = Yeh
		case Keheh:
			runes[i] = Kaf
		case HehYeh, HehGoal:
			runes[i] = Heh
		case HamzaAbove: // necessary for HEH + HAMZA
			runes = analysis.DeleteRune(runes, i)
			i--
		}
	}
	return analysis.BuildTermFromRunes(runes)
}
Exemple #9
0
func normalize(input []byte) []byte {
	state := N
	runes := bytes.Runes(input)
	for i := 0; i < len(runes); i++ {
		switch runes[i] {
		case 'a', 'o':
			state = U
		case 'u':
			if state == N {
				state = U
			} else {
				state = V
			}
		case 'e':
			if state == U {
				runes = analysis.DeleteRune(runes, i)
				i--
			}
			state = V
		case 'i', 'q', 'y':
			state = V
		case 'ä':
			runes[i] = 'a'
			state = V
		case 'ö':
			runes[i] = 'o'
			state = V
		case 'ü':
			runes[i] = 'u'
			state = V
		case 'ß':
			runes[i] = 's'
			i++
			// newrunes := make([]rune, len(runes)+1)
			// copy(newrunes, runes)
			// runes = newrunes
			// runes[i] = 's'
			runes = analysis.InsertRune(runes, i, 's')
			state = N
		default:
			state = N
		}
	}
	return analysis.BuildTermFromRunes(runes)
}
Exemple #10
0
func normalize(input []byte) []byte {
	runes := bytes.Runes(input)
	for i := 0; i < len(runes); i++ {
		switch runes[i] {
		case Yeh, DotlessYeh:
			runes[i] = FarsiYeh
		case Kaf:
			runes[i] = Keheh
		case Zwnj:
			if i > 0 && runes[i-1] == Heh {
				runes[i-1] = Ae
			}
			runes = analysis.DeleteRune(runes, i)
			i--
		case Heh:
			if i == len(runes)-1 {
				runes[i] = Ae
			}
		case TehMarbuta:
			runes[i] = Ae
		case HehDoachashmee:
			runes[i] = Heh
		case Reh:
			if i == 0 {
				runes[i] = Rreh
			}
		case RrehAbove:
			runes[i] = Rreh
		case Tatweel, Kasratan, Dammatan, Fathatan, Fatha, Damma, Kasra, Shadda, Sukun:
			runes = analysis.DeleteRune(runes, i)
			i--
		default:
			if unicode.In(runes[i], unicode.Cf) {
				runes = analysis.DeleteRune(runes, i)
				i--
			}
		}
	}
	return analysis.BuildTermFromRunes(runes)
}
Exemple #11
0
func normalize(input []byte) []byte {
	runes := bytes.Runes(input)
	for i := 0; i < len(runes); i++ {
		switch runes[i] {
		// dead n -> bindu
		case '\u0928':
			if i+1 < len(runes) && runes[i+1] == '\u094D' {
				runes[i] = '\u0902'
				runes = analysis.DeleteRune(runes, i+1)
			}
		// candrabindu -> bindu
		case '\u0901':
			runes[i] = '\u0902'
		// nukta deletions
		case '\u093C':
			runes = analysis.DeleteRune(runes, i)
			i--
		case '\u0929':
			runes[i] = '\u0928'
		case '\u0931':
			runes[i] = '\u0930'
		case '\u0934':
			runes[i] = '\u0933'
		case '\u0958':
			runes[i] = '\u0915'
		case '\u0959':
			runes[i] = '\u0916'
		case '\u095A':
			runes[i] = '\u0917'
		case '\u095B':
			runes[i] = '\u091C'
		case '\u095C':
			runes[i] = '\u0921'
		case '\u095D':
			runes[i] = '\u0922'
		case '\u095E':
			runes[i] = '\u092B'
		case '\u095F':
			runes[i] = '\u092F'
			// zwj/zwnj -> delete
		case '\u200D', '\u200C':
			runes = analysis.DeleteRune(runes, i)
			i--
			// virama -> delete
		case '\u094D':
			runes = analysis.DeleteRune(runes, i)
			i--
			// chandra/short -> replace
		case '\u0945', '\u0946':
			runes[i] = '\u0947'
		case '\u0949', '\u094A':
			runes[i] = '\u094B'
		case '\u090D', '\u090E':
			runes[i] = '\u090F'
		case '\u0911', '\u0912':
			runes[i] = '\u0913'
		case '\u0972':
			runes[i] = '\u0905'
			// long -> short ind. vowels
		case '\u0906':
			runes[i] = '\u0905'
		case '\u0908':
			runes[i] = '\u0907'
		case '\u090A':
			runes[i] = '\u0909'
		case '\u0960':
			runes[i] = '\u090B'
		case '\u0961':
			runes[i] = '\u090C'
		case '\u0910':
			runes[i] = '\u090F'
		case '\u0914':
			runes[i] = '\u0913'
			// long -> short dep. vowels
		case '\u0940':
			runes[i] = '\u093F'
		case '\u0942':
			runes[i] = '\u0941'
		case '\u0944':
			runes[i] = '\u0943'
		case '\u0963':
			runes[i] = '\u0962'
		case '\u0948':
			runes[i] = '\u0947'
		case '\u094C':
			runes[i] = '\u094B'
		}
	}
	return analysis.BuildTermFromRunes(runes)
}
Exemple #12
0
func buildTokenFromTerm(buffer []rune) *analysis.Token {
	return &analysis.Token{
		Term: analysis.BuildTermFromRunes(buffer),
	}
}