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

analysis/token/stop/stop.go

@@ -0,0 +1,73 @@
+//  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 stop implements a TokenFilter removing tokens found in
+// a TokenMap.
+//
+// It constructor takes the following arguments:
+//
+// "stop_token_map" (string): the name of the token map identifying tokens to
+// remove.
+package stop
+
+import (
+	"fmt"
+
+	"github.com/blevesearch/bleve/v2/analysis"
+	"github.com/blevesearch/bleve/v2/registry"
+)
+
+const Name = "stop_tokens"
+
+type StopTokensFilter struct {
+	stopTokens analysis.TokenMap
+}
+
+func NewStopTokensFilter(stopTokens analysis.TokenMap) *StopTokensFilter {
+	return &StopTokensFilter{
+		stopTokens: stopTokens,
+	}
+}
+
+func (f *StopTokensFilter) Filter(input analysis.TokenStream) analysis.TokenStream {
+	j := 0
+	for _, token := range input {
+		_, isStopToken := f.stopTokens[string(token.Term)]
+		if !isStopToken {
+			input[j] = token
+			j++
+		}
+	}
+
+	return input[:j]
+}
+
+func StopTokensFilterConstructor(config map[string]interface{}, cache *registry.Cache) (analysis.TokenFilter, error) {
+	stopTokenMapName, ok := config["stop_token_map"].(string)
+	if !ok {
+		return nil, fmt.Errorf("must specify stop_token_map")
+	}
+	stopTokenMap, err := cache.TokenMapNamed(stopTokenMapName)
+	if err != nil {
+		return nil, fmt.Errorf("error building stop words filter: %v", err)
+	}
+	return NewStopTokensFilter(stopTokenMap), nil
+}
+
+func init() {
+	err := registry.RegisterTokenFilter(Name, StopTokensFilterConstructor)
+	if err != nil {
+		panic(err)
+	}
+}

analysis/token/stop/stop_test.go

@@ -0,0 +1,124 @@
+//  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 stop
+
+import (
+	"reflect"
+	"testing"
+
+	"github.com/blevesearch/bleve/v2/analysis"
+	"github.com/blevesearch/bleve/v2/analysis/tokenmap"
+	"github.com/blevesearch/bleve/v2/registry"
+)
+
+func TestStopWordsFilter(t *testing.T) {
+
+	inputTokenStream := analysis.TokenStream{
+		&analysis.Token{
+			Term: []byte("a"),
+		},
+		&analysis.Token{
+			Term: []byte("walk"),
+		},
+		&analysis.Token{
+			Term: []byte("in"),
+		},
+		&analysis.Token{
+			Term: []byte("the"),
+		},
+		&analysis.Token{
+			Term: []byte("park"),
+		},
+	}
+
+	expectedTokenStream := analysis.TokenStream{
+		&analysis.Token{
+			Term: []byte("walk"),
+		},
+		&analysis.Token{
+			Term: []byte("park"),
+		},
+	}
+
+	cache := registry.NewCache()
+	stopListConfig := map[string]interface{}{
+		"type":   tokenmap.Name,
+		"tokens": []interface{}{"a", "in", "the"},
+	}
+	_, err := cache.DefineTokenMap("stop_test", stopListConfig)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	stopConfig := map[string]interface{}{
+		"type":           "stop_tokens",
+		"stop_token_map": "stop_test",
+	}
+	stopFilter, err := cache.DefineTokenFilter("stop_test", stopConfig)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	ouputTokenStream := stopFilter.Filter(inputTokenStream)
+	if !reflect.DeepEqual(ouputTokenStream, expectedTokenStream) {
+		t.Errorf("expected %#v got %#v", expectedTokenStream, ouputTokenStream)
+	}
+}
+
+func BenchmarkStopWordsFilter(b *testing.B) {
+
+	inputTokenStream := analysis.TokenStream{
+		&analysis.Token{
+			Term: []byte("a"),
+		},
+		&analysis.Token{
+			Term: []byte("walk"),
+		},
+		&analysis.Token{
+			Term: []byte("in"),
+		},
+		&analysis.Token{
+			Term: []byte("the"),
+		},
+		&analysis.Token{
+			Term: []byte("park"),
+		},
+	}
+
+	cache := registry.NewCache()
+	stopListConfig := map[string]interface{}{
+		"type":   tokenmap.Name,
+		"tokens": []interface{}{"a", "in", "the"},
+	}
+	_, err := cache.DefineTokenMap("stop_test", stopListConfig)
+	if err != nil {
+		b.Fatal(err)
+	}
+
+	stopConfig := map[string]interface{}{
+		"type":           "stop_tokens",
+		"stop_token_map": "stop_test",
+	}
+	stopFilter, err := cache.DefineTokenFilter("stop_test", stopConfig)
+	if err != nil {
+		b.Fatal(err)
+	}
+	b.ResetTimer()
+
+	for i := 0; i < b.N; i++ {
+		stopFilter.Filter(inputTokenStream)
+	}
+
+}