Move sexp into query

query/sexp/session.go

@@ -0,0 +1,122 @@
+// Copyright 2014 The Cayley Authors. All rights reserved.
+//
+// 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 sexp
+
+// Defines a running session of the sexp query language.
+
+import (
+	"errors"
+	"fmt"
+	"sort"
+
+	"github.com/google/cayley/graph"
+	"github.com/google/cayley/query"
+)
+
+type Session struct {
+	ts    graph.TripleStore
+	debug bool
+}
+
+func NewSession(inputTripleStore graph.TripleStore) *Session {
+	var s Session
+	s.ts = inputTripleStore
+	return &s
+}
+
+func (s *Session) ToggleDebug() {
+	s.debug = !s.debug
+}
+
+func (s *Session) InputParses(input string) (query.ParseResult, error) {
+	var parenDepth int
+	for i, x := range input {
+		if x == '(' {
+			parenDepth++
+		}
+		if x == ')' {
+			parenDepth--
+			if parenDepth < 0 {
+				min := 0
+				if (i - 10) > min {
+					min = i - 10
+				}
+				return query.ParseFail, errors.New(fmt.Sprintf("Too many close parens at char %d: %s", i, input[min:i]))
+			}
+		}
+	}
+	if parenDepth > 0 {
+		return query.ParseMore, nil
+	}
+	if len(ParseString(input)) > 0 {
+		return query.Parsed, nil
+	}
+	return query.ParseFail, errors.New("Invalid Syntax")
+}
+
+func (s *Session) ExecInput(input string, out chan interface{}, limit int) {
+	it := BuildIteratorTreeForQuery(s.ts, input)
+	newIt, changed := it.Optimize()
+	if changed {
+		it = newIt
+	}
+
+	if s.debug {
+		fmt.Println(it.DebugString(0))
+	}
+	nResults := 0
+	for {
+		_, ok := graph.Next(it)
+		if !ok {
+			break
+		}
+		tags := make(map[string]graph.Value)
+		it.TagResults(tags)
+		out <- &tags
+		nResults++
+		if nResults > limit && limit != -1 {
+			break
+		}
+		for it.NextResult() == true {
+			tags := make(map[string]graph.Value)
+			it.TagResults(tags)
+			out <- &tags
+			nResults++
+			if nResults > limit && limit != -1 {
+				break
+			}
+		}
+	}
+	close(out)
+}
+
+func (s *Session) ToText(result interface{}) string {
+	out := fmt.Sprintln("****")
+	tags := result.(map[string]graph.Value)
+	tagKeys := make([]string, len(tags))
+	i := 0
+	for k := range tags {
+		tagKeys[i] = k
+		i++
+	}
+	sort.Strings(tagKeys)
+	for _, k := range tagKeys {
+		if k == "$_" {
+			continue
+		}
+		out += fmt.Sprintf("%s : %s\n", k, s.ts.NameOf(tags[k]))
+	}
+	return out
+}