snapshot of https://github.com/blevesearch/bleve.git (master, 2026-09-15; blobs > 131072B omitted)

analysis/token/porter/porter.go

@@ -0,0 +1,56 @@
+//  Copyright (c) 2014 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 porter
+
+import (
+	"bytes"
+
+	"github.com/blevesearch/bleve/v2/analysis"
+	"github.com/blevesearch/bleve/v2/registry"
+
+	"github.com/blevesearch/go-porterstemmer"
+)
+
+const Name = "stemmer_porter"
+
+type PorterStemmer struct {
+}
+
+func NewPorterStemmer() *PorterStemmer {
+	return &PorterStemmer{}
+}
+
+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
+}
+
+func PorterStemmerConstructor(config map[string]interface{}, cache *registry.Cache) (analysis.TokenFilter, error) {
+	return NewPorterStemmer(), nil
+}
+
+func init() {
+	err := registry.RegisterTokenFilter(Name, PorterStemmerConstructor)
+	if err != nil {
+		panic(err)
+	}
+}

analysis/token/porter/porter_test.go

@@ -0,0 +1,115 @@
+//  Copyright (c) 2014 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 porter
+
+import (
+	"reflect"
+	"testing"
+
+	"github.com/blevesearch/bleve/v2/analysis"
+)
+
+func TestPorterStemmer(t *testing.T) {
+
+	inputTokenStream := analysis.TokenStream{
+		&analysis.Token{
+			Term: []byte("walking"),
+		},
+		&analysis.Token{
+			Term: []byte("talked"),
+		},
+		&analysis.Token{
+			Term: []byte("business"),
+		},
+		&analysis.Token{
+			Term:    []byte("protected"),
+			KeyWord: true,
+		},
+		&analysis.Token{
+			Term: []byte("cat"),
+		},
+		&analysis.Token{
+			Term: []byte("done"),
+		},
+		// a term which does stem, but does not change length
+		&analysis.Token{
+			Term: []byte("marty"),
+		},
+	}
+
+	expectedTokenStream := analysis.TokenStream{
+		&analysis.Token{
+			Term: []byte("walk"),
+		},
+		&analysis.Token{
+			Term: []byte("talk"),
+		},
+		&analysis.Token{
+			Term: []byte("busi"),
+		},
+		&analysis.Token{
+			Term:    []byte("protected"),
+			KeyWord: true,
+		},
+		&analysis.Token{
+			Term: []byte("cat"),
+		},
+		&analysis.Token{
+			Term: []byte("done"),
+		},
+		&analysis.Token{
+			Term: []byte("marti"),
+		},
+	}
+
+	filter := NewPorterStemmer()
+	ouputTokenStream := filter.Filter(inputTokenStream)
+	if !reflect.DeepEqual(ouputTokenStream, expectedTokenStream) {
+		t.Errorf("expected %#v got %#v", expectedTokenStream[3], ouputTokenStream[3])
+	}
+}
+
+func BenchmarkPorterStemmer(b *testing.B) {
+
+	inputTokenStream := analysis.TokenStream{
+		&analysis.Token{
+			Term: []byte("walking"),
+		},
+		&analysis.Token{
+			Term: []byte("talked"),
+		},
+		&analysis.Token{
+			Term: []byte("business"),
+		},
+		&analysis.Token{
+			Term:    []byte("protected"),
+			KeyWord: true,
+		},
+		&analysis.Token{
+			Term: []byte("cat"),
+		},
+		&analysis.Token{
+			Term: []byte("done"),
+		},
+	}
+
+	filter := NewPorterStemmer()
+	b.ResetTimer()
+
+	for i := 0; i < b.N; i++ {
+		filter.Filter(inputTokenStream)
+	}
+
+}