added MatchPhrasePrefixQuery

query.go

@@ -173,6 +173,22 @@ func NewPrefixQuery(prefix string) *query.PrefixQuery {
 	return query.NewPrefixQuery(prefix)
 }
 
+// NewMatchPhrasePrefixQuery creates a new Query which finds
+// documents containing phrases that start with the
+// specified phrase prefix.
+
+// NewMatchPhrasePrefixQuery creates a new Query
+// for matching phrase prefix in the index.
+// An Analyzer is chosen based on the field.
+// Input text is analyzed using this analyzer.
+// Token terms resulting from this analysis are
+// used to build a search phrase.  Result documents
+// must match this phrase prefix. Queried field must have been indexed with
+// IncludeTermVectors set to true.
+func NewMatchPhrasePrefixQuery(matchPhrasePrefix string) *query.MatchPhrasePrefixQuery {
+	return query.NewMatchPhrasePrefixQuery(matchPhrasePrefix)
+}
+
 // NewRegexpQuery creates a new Query which finds
 // documents containing terms that match the
 // specified regular expression.

search/query/match_phrase_prefix.go

@@ -0,0 +1,106 @@
+//  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 query
+
+import (
+	"fmt"
+
+	"github.com/blevesearch/bleve/index"
+	"github.com/blevesearch/bleve/mapping"
+	"github.com/blevesearch/bleve/search"
+)
+
+type MatchPhrasePrefixQuery struct {
+	MatchPhrasePrefix string `json:"match_phrase_prefix"`
+	FieldVal          string `json:"field,omitempty"`
+	Analyzer          string `json:"analyzer,omitempty"`
+	BoostVal          *Boost `json:"boost,omitempty"`
+}
+
+// NewMatchPhrasePrefixQuery creates a new Query
+// for matching phrase prefix in the index.
+// An Analyzer is chosen based on the field.
+// Input text is analyzed using this analyzer.
+// Token terms resulting from this analysis are
+// used to build a search phrase.  Result documents
+// must match this phrase prefix. Queried field must have been indexed with
+// IncludeTermVectors set to true.
+func NewMatchPhrasePrefixQuery(matchPhrasePrefix string) *MatchPhrasePrefixQuery {
+	return &MatchPhrasePrefixQuery{
+		MatchPhrasePrefix: matchPhrasePrefix,
+	}
+}
+
+func (q *MatchPhrasePrefixQuery) SetBoost(b float64) {
+	boost := Boost(b)
+	q.BoostVal = &boost
+}
+
+func (q *MatchPhrasePrefixQuery) Boost() float64 {
+	return q.BoostVal.Value()
+}
+
+func (q *MatchPhrasePrefixQuery) SetField(f string) {
+	q.FieldVal = f
+}
+
+func (q *MatchPhrasePrefixQuery) Field() string {
+	return q.FieldVal
+}
+
+func (q *MatchPhrasePrefixQuery) Searcher(i index.IndexReader, m mapping.IndexMapping, options search.SearcherOptions) (search.Searcher, error) {
+	field := q.FieldVal
+	if q.FieldVal == "" {
+		field = m.DefaultSearchField()
+	}
+
+	analyzerName := ""
+	if q.Analyzer != "" {
+		analyzerName = q.Analyzer
+	} else {
+		analyzerName = m.AnalyzerNameForPath(field)
+	}
+	analyzer := m.AnalyzerNamed(analyzerName)
+	if analyzer == nil {
+		return nil, fmt.Errorf("no analyzer named '%s' registered", q.Analyzer)
+	}
+
+	tokens := analyzer.Analyze([]byte(q.MatchPhrasePrefix))
+	if len(tokens) > 0 {
+		phrase := tokenStreamToPhrase(tokens)
+		if len(phrase) > 0 {
+			// expand tokens at last position to terms from dictionary
+			var terms []string
+			for _, prefix := range phrase[len(phrase)-1] {
+				fieldDict, err := i.FieldDictPrefix(field, []byte(prefix))
+				if err != nil {
+					return nil, err
+				}
+				tfd, err := fieldDict.Next()
+				for err == nil && tfd != nil {
+					terms = append(terms, tfd.Term)
+					tfd, err = fieldDict.Next()
+				}
+			}
+			phrase[len(phrase)-1] = terms
+		}
+		phraseQuery := NewMultiPhraseQuery(phrase, field)
+		phraseQuery.SetBoost(q.BoostVal.Value())
+		return phraseQuery.Searcher(i, m, options)
+	}
+
+	noneQuery := NewMatchNoneQuery()
+	return noneQuery.Searcher(i, m, options)
+}