Adding upstream version 2.5.1.

Signed-off-by: Daniel Baumann <daniel@debian.org>

analysis/lang/fr/minimal_stemmer_fr.go

@@ -0,0 +1,82 @@
+//  Copyright (c) 2015 Couchbase, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// 		http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package fr
+
+import (
+	"bytes"
+
+	"github.com/blevesearch/bleve/v2/analysis"
+	"github.com/blevesearch/bleve/v2/registry"
+)
+
+const MinimalStemmerName = "stemmer_fr_min"
+
+type FrenchMinimalStemmerFilter struct {
+}
+
+func NewFrenchMinimalStemmerFilter() *FrenchMinimalStemmerFilter {
+	return &FrenchMinimalStemmerFilter{}
+}
+
+func (s *FrenchMinimalStemmerFilter) Filter(input analysis.TokenStream) analysis.TokenStream {
+	for _, token := range input {
+		runes := bytes.Runes(token.Term)
+		runes = minstem(runes)
+		token.Term = analysis.BuildTermFromRunes(runes)
+	}
+	return input
+}
+
+func minstem(input []rune) []rune {
+
+	if len(input) < 6 {
+		return input
+	}
+
+	if input[len(input)-1] == 'x' {
+		if input[len(input)-3] == 'a' && input[len(input)-2] == 'u' {
+			input[len(input)-2] = 'l'
+		}
+		return input[0 : len(input)-1]
+	}
+
+	if input[len(input)-1] == 's' {
+		input = input[0 : len(input)-1]
+	}
+	if input[len(input)-1] == 'r' {
+		input = input[0 : len(input)-1]
+	}
+	if input[len(input)-1] == 'e' {
+		input = input[0 : len(input)-1]
+	}
+	if input[len(input)-1] == 'é' {
+		input = input[0 : len(input)-1]
+	}
+	if input[len(input)-1] == input[len(input)-2] {
+		input = input[0 : len(input)-1]
+	}
+	return input
+}
+
+func FrenchMinimalStemmerFilterConstructor(config map[string]interface{}, cache *registry.Cache) (analysis.TokenFilter, error) {
+	return NewFrenchMinimalStemmerFilter(), nil
+}
+
+func init() {
+	err := registry.RegisterTokenFilter(MinimalStemmerName, FrenchMinimalStemmerFilterConstructor)
+	if err != nil {
+		panic(err)
+	}
+}