added regexp and wildcard queries

fixes #152

query.go

@@ -189,5 +189,23 @@ func ParseQuery(input []byte) (Query, error) {
 		}
 		return &rv, nil
 	}
+	_, hasRegexp := tmp["regexp"]
+	if hasRegexp {
+		var rv regexpQuery
+		err := json.Unmarshal(input, &rv)
+		if err != nil {
+			return nil, err
+		}
+		return &rv, nil
+	}
+	_, hasWildcard := tmp["wildcard"]
+	if hasWildcard {
+		var rv wildcardQuery
+		err := json.Unmarshal(input, &rv)
+		if err != nil {
+			return nil, err
+		}
+		return &rv, nil
+	}
 	return nil, ErrorUnknownQueryType
 }

query_regexp.go

@@ -0,0 +1,75 @@
+//  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 bleve
+
+import (
+	"regexp"
+
+	"github.com/blevesearch/bleve/index"
+	"github.com/blevesearch/bleve/search"
+	"github.com/blevesearch/bleve/search/searchers"
+)
+
+type regexpQuery struct {
+	Regexp   string  `json:"regexp"`
+	FieldVal string  `json:"field,omitempty"`
+	BoostVal float64 `json:"boost,omitempty"`
+	compiled *regexp.Regexp
+}
+
+// NewRegexpQuery creates a new Query which finds
+// documents containing terms that match the
+// specified regular expression.
+func NewRegexpQuery(regexp string) *regexpQuery {
+	return &regexpQuery{
+		Regexp:   regexp,
+		BoostVal: 1.0,
+	}
+}
+
+func (q *regexpQuery) Boost() float64 {
+	return q.BoostVal
+}
+
+func (q *regexpQuery) SetBoost(b float64) Query {
+	q.BoostVal = b
+	return q
+}
+
+func (q *regexpQuery) Field() string {
+	return q.FieldVal
+}
+
+func (q *regexpQuery) SetField(f string) Query {
+	q.FieldVal = f
+	return q
+}
+
+func (q *regexpQuery) Searcher(i index.IndexReader, m *IndexMapping, explain bool) (search.Searcher, error) {
+	field := q.FieldVal
+	if q.FieldVal == "" {
+		field = m.DefaultField
+	}
+	if q.compiled == nil {
+		var err error
+		q.compiled, err = regexp.Compile(q.Regexp)
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	return searchers.NewRegexpSearcher(i, q.compiled, field, q.BoostVal, explain)
+}
+
+func (q *regexpQuery) Validate() error {
+	var err error
+	q.compiled, err = regexp.Compile(q.Regexp)
+	return err
+}

query_wildcard.go

@@ -0,0 +1,102 @@
+//  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 bleve
+
+import (
+	"regexp"
+	"strings"
+
+	"github.com/blevesearch/bleve/index"
+	"github.com/blevesearch/bleve/search"
+	"github.com/blevesearch/bleve/search/searchers"
+)
+
+var wildcardRegexpReplacer = strings.NewReplacer(
+	// characters in the wildcard that must
+	// be escaped in the regexp
+	"+", `\+`,
+	"(", `\(`,
+	")", `\)`,
+	"^", `\^`,
+	"$", `\$`,
+	".", `\.`,
+	"{", `\{`,
+	"}", `\}`,
+	"[", `\[`,
+	"]", `\]`,
+	`|`, `\|`,
+	`\`, `\\`,
+	// wildcard characters
+	"*", ".*",
+	"?", ".")
+
+type wildcardQuery struct {
+	Wildcard string  `json:"wildcard"`
+	FieldVal string  `json:"field,omitempty"`
+	BoostVal float64 `json:"boost,omitempty"`
+	compiled *regexp.Regexp
+}
+
+// NewWildcardQuery creates a new Query which finds
+// documents containing terms that match the
+// specified wildcard.  In the wildcard pattern '*'
+// will match any sequence of 0 or more characters,
+// and '?' will match any single character.
+func NewWildcardQuery(wildcard string) *wildcardQuery {
+	return &wildcardQuery{
+		Wildcard: wildcard,
+		BoostVal: 1.0,
+	}
+}
+
+func (q *wildcardQuery) Boost() float64 {
+	return q.BoostVal
+}
+
+func (q *wildcardQuery) SetBoost(b float64) Query {
+	q.BoostVal = b
+	return q
+}
+
+func (q *wildcardQuery) Field() string {
+	return q.FieldVal
+}
+
+func (q *wildcardQuery) SetField(f string) Query {
+	q.FieldVal = f
+	return q
+}
+
+func (q *wildcardQuery) Searcher(i index.IndexReader, m *IndexMapping, explain bool) (search.Searcher, error) {
+	field := q.FieldVal
+	if q.FieldVal == "" {
+		field = m.DefaultField
+	}
+	if q.compiled == nil {
+		var err error
+		q.compiled, err = q.convertToRegexp()
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	return searchers.NewRegexpSearcher(i, q.compiled, field, q.BoostVal, explain)
+}
+
+func (q *wildcardQuery) Validate() error {
+	var err error
+	q.compiled, err = q.convertToRegexp()
+	return err
+}
+
+func (q *wildcardQuery) convertToRegexp() (*regexp.Regexp, error) {
+	regexpString := "^" + wildcardRegexpReplacer.Replace(q.Wildcard) + "$"
+	return regexp.Compile(regexpString)
+}

search/searchers/search_regexp.go

@@ -0,0 +1,108 @@
+//  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 searchers
+
+import (
+	"regexp"
+
+	"github.com/blevesearch/bleve/index"
+	"github.com/blevesearch/bleve/search"
+)
+
+type RegexpSearcher struct {
+	indexReader index.IndexReader
+	pattern     *regexp.Regexp
+	field       string
+	explain     bool
+	searcher    *DisjunctionSearcher
+}
+
+func NewRegexpSearcher(indexReader index.IndexReader, pattern *regexp.Regexp, field string, boost float64, explain bool) (*RegexpSearcher, error) {
+
+	prefixTerm, complete := pattern.LiteralPrefix()
+	candidateTerms := make([]string, 0)
+	if complete {
+		// there is no pattern
+		candidateTerms = append(candidateTerms, prefixTerm)
+	} else {
+		var fieldDict index.FieldDict
+		var err error
+		if len(prefixTerm) > 0 {
+			fieldDict, err = indexReader.FieldDictPrefix(field, []byte(prefixTerm))
+		} else {
+			fieldDict, err = indexReader.FieldDict(field)
+		}
+
+		// enumerate the terms and check against regexp
+		tfd, err := fieldDict.Next()
+		for err == nil && tfd != nil {
+			if pattern.MatchString(tfd.Term) {
+				candidateTerms = append(candidateTerms, tfd.Term)
+			}
+			tfd, err = fieldDict.Next()
+		}
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	// enumerate all the terms in the range
+	qsearchers := make([]search.Searcher, 0, 25)
+
+	for _, cterm := range candidateTerms {
+		qsearcher, err := NewTermSearcher(indexReader, cterm, field, 1.0, explain)
+		if err != nil {
+			return nil, err
+		}
+		qsearchers = append(qsearchers, qsearcher)
+	}
+
+	// build disjunction searcher of these ranges
+	searcher, err := NewDisjunctionSearcher(indexReader, qsearchers, 0, explain)
+	if err != nil {
+		return nil, err
+	}
+
+	return &RegexpSearcher{
+		indexReader: indexReader,
+		pattern:     pattern,
+		field:       field,
+		explain:     explain,
+		searcher:    searcher,
+	}, nil
+}
+func (s *RegexpSearcher) Count() uint64 {
+	return s.searcher.Count()
+}
+
+func (s *RegexpSearcher) Weight() float64 {
+	return s.searcher.Weight()
+}
+
+func (s *RegexpSearcher) SetQueryNorm(qnorm float64) {
+	s.searcher.SetQueryNorm(qnorm)
+}
+
+func (s *RegexpSearcher) Next() (*search.DocumentMatch, error) {
+	return s.searcher.Next()
+
+}
+
+func (s *RegexpSearcher) Advance(ID string) (*search.DocumentMatch, error) {
+	return s.searcher.Next()
+}
+
+func (s *RegexpSearcher) Close() error {
+	return s.searcher.Close()
+}
+
+func (s *RegexpSearcher) Min() int {
+	return 0
+}

search/searchers/search_regexp_test.go

@@ -0,0 +1,100 @@
+//  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 searchers
+
+import (
+	"regexp"
+	"testing"
+
+	"github.com/blevesearch/bleve/search"
+)
+
+func TestRegexpSearch(t *testing.T) {
+
+	twoDocIndexReader, err := twoDocIndex.Reader()
+	if err != nil {
+		t.Error(err)
+	}
+	defer twoDocIndexReader.Close()
+
+	pattern, err := regexp.Compile("ma.*")
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	regexpSearcher, err := NewRegexpSearcher(twoDocIndexReader, pattern, "name", 1.0, true)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	patternCo, err := regexp.Compile("co.*")
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	regexpSearcherCo, err := NewRegexpSearcher(twoDocIndexReader, patternCo, "desc", 1.0, true)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	tests := []struct {
+		searcher search.Searcher
+		results  []*search.DocumentMatch
+	}{
+		{
+			searcher: regexpSearcher,
+			results: []*search.DocumentMatch{
+				&search.DocumentMatch{
+					ID:    "1",
+					Score: 1.916290731874155,
+				},
+			},
+		},
+		{
+			searcher: regexpSearcherCo,
+			results: []*search.DocumentMatch{
+				&search.DocumentMatch{
+					ID:    "2",
+					Score: 0.33875554280828685,
+				},
+				&search.DocumentMatch{
+					ID:    "3",
+					Score: 0.33875554280828685,
+				},
+			},
+		},
+	}
+
+	for testIndex, test := range tests {
+		defer test.searcher.Close()
+
+		next, err := test.searcher.Next()
+		i := 0
+		for err == nil && next != nil {
+			if i < len(test.results) {
+				if next.ID != test.results[i].ID {
+					t.Errorf("expected result %d to have id %s got %s for test %d", i, test.results[i].ID, next.ID, testIndex)
+				}
+				if next.Score != test.results[i].Score {
+					t.Errorf("expected result %d to have score %v got  %v for test %d", i, test.results[i].Score, next.Score, testIndex)
+					t.Logf("scoring explanation: %s", next.Expl)
+				}
+			}
+			next, err = test.searcher.Next()
+			i++
+		}
+		if err != nil {
+			t.Fatalf("error iterating searcher: %v for test %d", err, testIndex)
+		}
+		if len(test.results) != i {
+			t.Errorf("expected %d results got %d for test %d", len(test.results), i, testIndex)
+		}
+	}
+}