Destutter filenames

query/mql/build_iterator.go

@@ -0,0 +1,181 @@
+// 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 mql
+
+import (
+	"errors"
+	"fmt"
+	"log"
+	"math"
+	"strings"
+
+	"github.com/google/cayley/graph"
+)
+
+func (m *MqlQuery) buildFixed(s string) graph.Iterator {
+	f := m.ses.ts.MakeFixed()
+	f.AddValue(m.ses.ts.GetIdFor(s))
+	return f
+}
+
+func (m *MqlQuery) buildResultIterator(path MqlPath) graph.Iterator {
+	all := m.ses.ts.GetNodesAllIterator()
+	all.AddTag(string(path))
+	return graph.NewOptionalIterator(all)
+}
+
+func (m *MqlQuery) BuildIteratorTree(query interface{}) {
+	m.isRepeated = make(map[MqlPath]bool)
+	m.queryStructure = make(map[MqlPath]map[string]interface{})
+	m.queryResult = make(map[MqlResultPath]map[string]interface{})
+	m.queryResult[""] = make(map[string]interface{})
+
+	m.it, m.err = m.buildIteratorTreeInternal(query, NewMqlPath())
+	if m.err != nil {
+		m.isError = true
+	}
+}
+
+func (m *MqlQuery) buildIteratorTreeInternal(query interface{}, path MqlPath) (graph.Iterator, error) {
+	var it graph.Iterator
+	var err error
+	err = nil
+	switch t := query.(type) {
+	case bool:
+		// for JSON booleans
+		// Treat the bool as a string and call it a day.
+		// Things which are really bool-like are special cases and will be dealt with separately.
+		if t {
+			it = m.buildFixed("true")
+		}
+		it = m.buildFixed("false")
+	case float64:
+		// for JSON numbers
+		// Damn you, Javascript, and your lack of integer values.
+		if math.Floor(t) == t {
+			// Treat it like an integer.
+			it = m.buildFixed(fmt.Sprintf("%d", t))
+		} else {
+			it = m.buildFixed(fmt.Sprintf("%f", t))
+		}
+	case string:
+		// for JSON strings
+		it = m.buildFixed(t)
+	case []interface{}:
+		// for JSON arrays
+		m.isRepeated[path] = true
+		if len(t) == 0 {
+			it = m.buildResultIterator(path)
+		} else if len(t) == 1 {
+			it, err = m.buildIteratorTreeInternal(t[0], path)
+		} else {
+			err = errors.New(fmt.Sprintf("Multiple fields at location root%s", path.DisplayString()))
+		}
+	case map[string]interface{}:
+		// for JSON objects
+		it, err = m.buildIteratorTreeMapInternal(t, path)
+	case nil:
+		it = m.buildResultIterator(path)
+	default:
+		log.Fatal("Unknown JSON type?", query)
+	}
+	if err != nil {
+		return nil, err
+	}
+	it.AddTag(string(path))
+	return it, nil
+}
+
+func (m *MqlQuery) buildIteratorTreeMapInternal(query map[string]interface{}, path MqlPath) (graph.Iterator, error) {
+	it := graph.NewAndIterator()
+	it.AddSubIterator(m.ses.ts.GetNodesAllIterator())
+	var err error
+	err = nil
+	outputStructure := make(map[string]interface{})
+	for key, subquery := range query {
+		outputStructure[key] = nil
+		reverse := false
+		pred := key
+		if strings.HasPrefix(pred, "@") {
+			i := strings.Index(pred, ":")
+			if i != -1 {
+				pred = pred[(i + 1):]
+			}
+		}
+		if strings.HasPrefix(pred, "!") {
+			reverse = true
+			pred = strings.TrimPrefix(pred, "!")
+		}
+
+		// Other special constructs here
+		var subit graph.Iterator
+		if key == "id" {
+			subit, err = m.buildIteratorTreeInternal(subquery, path.Follow(key))
+			if err != nil {
+				return nil, err
+			}
+			it.AddSubIterator(subit)
+		} else {
+			subit, err = m.buildIteratorTreeInternal(subquery, path.Follow(key))
+			if err != nil {
+				return nil, err
+			}
+			subAnd := graph.NewAndIterator()
+			predFixed := m.ses.ts.MakeFixed()
+			predFixed.AddValue(m.ses.ts.GetIdFor(pred))
+			subAnd.AddSubIterator(graph.NewLinksToIterator(m.ses.ts, predFixed, "p"))
+			if reverse {
+				lto := graph.NewLinksToIterator(m.ses.ts, subit, "s")
+				subAnd.AddSubIterator(lto)
+				hasa := graph.NewHasaIterator(m.ses.ts, subAnd, "o")
+				it.AddSubIterator(hasa)
+			} else {
+				lto := graph.NewLinksToIterator(m.ses.ts, subit, "o")
+				subAnd.AddSubIterator(lto)
+				hasa := graph.NewHasaIterator(m.ses.ts, subAnd, "s")
+				it.AddSubIterator(hasa)
+			}
+		}
+	}
+	if err != nil {
+		return nil, err
+	}
+	m.queryStructure[path] = outputStructure
+	return it, nil
+}
+
+type MqlResultPathSlice []MqlResultPath
+
+func (sl MqlResultPathSlice) Len() int {
+	return len(sl)
+}
+
+func (sl MqlResultPathSlice) Less(i, j int) bool {
+	iLen := len(strings.Split(string(sl[i]), "\x30"))
+	jLen := len(strings.Split(string(sl[j]), "\x30"))
+	if iLen < jLen {
+		return true
+	}
+	if iLen == jLen {
+		if len(string(sl[i])) < len(string(sl[j])) {
+			return true
+		}
+	}
+	return false
+}
+
+func (sl MqlResultPathSlice) Swap(i, j int) {
+	sl[i], sl[j] = sl[j], sl[i]
+}