diff --git a/go/vendor/github.com/globalsign/mgo/bson/decode.go b/go/vendor/github.com/globalsign/mgo/bson/decode.go
new file mode 100644
index 0000000..658856a
--- /dev/null
+++ b/go/vendor/github.com/globalsign/mgo/bson/decode.go
@@ -0,0 +1,1055 @@
+// BSON library for Go
+//
+// Copyright (c) 2010-2012 - Gustavo Niemeyer <gustavo@niemeyer.net>
+//
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are met:
+//
+// 1. Redistributions of source code must retain the above copyright notice, this
+//    list of conditions and the following disclaimer.
+// 2. Redistributions in binary form must reproduce the above copyright notice,
+//    this list of conditions and the following disclaimer in the documentation
+//    and/or other materials provided with the distribution.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+// ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+// WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+// DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
+// ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+// (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+// LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+// ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+// SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+// gobson - BSON library for Go.
+
+package bson
+
+import (
+	"errors"
+	"fmt"
+	"io"
+	"math"
+	"net/url"
+	"reflect"
+	"strconv"
+	"sync"
+	"time"
+)
+
+type decoder struct {
+	in      []byte
+	i       int
+	docType reflect.Type
+}
+
+var typeM = reflect.TypeOf(M{})
+
+func newDecoder(in []byte) *decoder {
+	return &decoder{in, 0, typeM}
+}
+
+// --------------------------------------------------------------------------
+// Some helper functions.
+
+func corrupted() {
+	panic("Document is corrupted")
+}
+
+// --------------------------------------------------------------------------
+// Unmarshaling of documents.
+
+const (
+	setterUnknown = iota
+	setterNone
+	setterType
+	setterAddr
+)
+
+var setterStyles map[reflect.Type]int
+var setterIface reflect.Type
+var setterMutex sync.RWMutex
+
+func init() {
+	var iface Setter
+	setterIface = reflect.TypeOf(&iface).Elem()
+	setterStyles = make(map[reflect.Type]int)
+}
+
+func setterStyle(outt reflect.Type) int {
+	setterMutex.RLock()
+	style := setterStyles[outt]
+	setterMutex.RUnlock()
+	if style != setterUnknown {
+		return style
+	}
+
+	setterMutex.Lock()
+	defer setterMutex.Unlock()
+	if outt.Implements(setterIface) {
+		style = setterType
+	} else if reflect.PtrTo(outt).Implements(setterIface) {
+		style = setterAddr
+	} else {
+		style = setterNone
+	}
+	setterStyles[outt] = style
+	return style
+}
+
+func getSetter(outt reflect.Type, out reflect.Value) Setter {
+	style := setterStyle(outt)
+	if style == setterNone {
+		return nil
+	}
+	if style == setterAddr {
+		if !out.CanAddr() {
+			return nil
+		}
+		out = out.Addr()
+	} else if outt.Kind() == reflect.Ptr && out.IsNil() {
+		out.Set(reflect.New(outt.Elem()))
+	}
+	return out.Interface().(Setter)
+}
+
+func clearMap(m reflect.Value) {
+	var none reflect.Value
+	for _, k := range m.MapKeys() {
+		m.SetMapIndex(k, none)
+	}
+}
+
+func (d *decoder) readDocTo(out reflect.Value) {
+	var elemType reflect.Type
+	outt := out.Type()
+	outk := outt.Kind()
+
+	for {
+		if outk == reflect.Ptr && out.IsNil() {
+			out.Set(reflect.New(outt.Elem()))
+		}
+		if setter := getSetter(outt, out); setter != nil {
+			raw := d.readRaw(ElementDocument)
+			err := setter.SetBSON(raw)
+			if _, ok := err.(*TypeError); err != nil && !ok {
+				panic(err)
+			}
+			return
+		}
+		if outk == reflect.Ptr {
+			out = out.Elem()
+			outt = out.Type()
+			outk = out.Kind()
+			continue
+		}
+		break
+	}
+
+	var fieldsMap map[string]fieldInfo
+	var inlineMap reflect.Value
+	if outt == typeRaw {
+		out.Set(reflect.ValueOf(d.readRaw(ElementDocument)))
+		return
+	}
+
+	origout := out
+	if outk == reflect.Interface {
+		if d.docType.Kind() == reflect.Map {
+			mv := reflect.MakeMap(d.docType)
+			out.Set(mv)
+			out = mv
+		} else {
+			dv := reflect.New(d.docType).Elem()
+			out.Set(dv)
+			out = dv
+		}
+		outt = out.Type()
+		outk = outt.Kind()
+	}
+
+	docType := d.docType
+	keyType := typeString
+	convertKey := false
+	switch outk {
+	case reflect.Map:
+		keyType = outt.Key()
+		if keyType != typeString {
+			convertKey = true
+		}
+		elemType = outt.Elem()
+		if elemType == typeIface {
+			d.docType = outt
+		}
+		if out.IsNil() {
+			out.Set(reflect.MakeMap(out.Type()))
+		} else if out.Len() > 0 {
+			clearMap(out)
+		}
+	case reflect.Struct:
+		sinfo, err := getStructInfo(out.Type())
+		if err != nil {
+			panic(err)
+		}
+		fieldsMap = sinfo.FieldsMap
+		out.Set(sinfo.Zero)
+		if sinfo.InlineMap != -1 {
+			inlineMap = out.Field(sinfo.InlineMap)
+			if !inlineMap.IsNil() && inlineMap.Len() > 0 {
+				clearMap(inlineMap)
+			}
+			elemType = inlineMap.Type().Elem()
+			if elemType == typeIface {
+				d.docType = inlineMap.Type()
+			}
+		}
+	case reflect.Slice:
+		switch outt.Elem() {
+		case typeDocElem:
+			origout.Set(d.readDocElems(outt))
+			return
+		case typeRawDocElem:
+			origout.Set(d.readRawDocElems(outt))
+			return
+		}
+		fallthrough
+	default:
+		panic("Unsupported document type for unmarshalling: " + out.Type().String())
+	}
+
+	end := int(d.readInt32())
+	end += d.i - 4
+	if end <= d.i || end > len(d.in) || d.in[end-1] != '\x00' {
+		corrupted()
+	}
+	for d.in[d.i] != '\x00' {
+		kind := d.readByte()
+		name := d.readCStr()
+		if d.i >= end {
+			corrupted()
+		}
+
+		switch outk {
+		case reflect.Map:
+			e := reflect.New(elemType).Elem()
+			if d.readElemTo(e, kind) {
+				k := reflect.ValueOf(name)
+				if convertKey {
+					mapKeyType := out.Type().Key()
+					mapKeyKind := mapKeyType.Kind()
+
+					switch mapKeyKind {
+					case reflect.Int:
+						fallthrough
+					case reflect.Int8:
+						fallthrough
+					case reflect.Int16:
+						fallthrough
+					case reflect.Int32:
+						fallthrough
+					case reflect.Int64:
+						fallthrough
+					case reflect.Uint:
+						fallthrough
+					case reflect.Uint8:
+						fallthrough
+					case reflect.Uint16:
+						fallthrough
+					case reflect.Uint32:
+						fallthrough
+					case reflect.Uint64:
+						fallthrough
+					case reflect.Float32:
+						fallthrough
+					case reflect.Float64:
+						parsed := d.parseMapKeyAsFloat(k, mapKeyKind)
+						k = reflect.ValueOf(parsed)
+					case reflect.String:
+						mapKeyType = keyType
+					default:
+						panic("BSON map must have string or decimal keys. Got: " + outt.String())
+					}
+
+					k = k.Convert(mapKeyType)
+				}
+				out.SetMapIndex(k, e)
+			}
+		case reflect.Struct:
+			if info, ok := fieldsMap[name]; ok {
+				if info.Inline == nil {
+					d.readElemTo(out.Field(info.Num), kind)
+				} else {
+					d.readElemTo(out.FieldByIndex(info.Inline), kind)
+				}
+			} else if inlineMap.IsValid() {
+				if inlineMap.IsNil() {
+					inlineMap.Set(reflect.MakeMap(inlineMap.Type()))
+				}
+				e := reflect.New(elemType).Elem()
+				if d.readElemTo(e, kind) {
+					inlineMap.SetMapIndex(reflect.ValueOf(name), e)
+				}
+			} else {
+				d.dropElem(kind)
+			}
+		case reflect.Slice:
+		}
+
+		if d.i >= end {
+			corrupted()
+		}
+	}
+	d.i++ // '\x00'
+	if d.i != end {
+		corrupted()
+	}
+	d.docType = docType
+}
+
+func (decoder) parseMapKeyAsFloat(k reflect.Value, mapKeyKind reflect.Kind) float64 {
+	parsed, err := strconv.ParseFloat(k.String(), 64)
+	if err != nil {
+		panic("Map key is defined to be a decimal type (" + mapKeyKind.String() + ") but got error " +
+			err.Error())
+	}
+
+	return parsed
+}
+
+func (d *decoder) readArrayDocTo(out reflect.Value) {
+	end := int(d.readInt32())
+	end += d.i - 4
+	if end <= d.i || end > len(d.in) || d.in[end-1] != '\x00' {
+		corrupted()
+	}
+	i := 0
+	l := out.Len()
+	for d.in[d.i] != '\x00' {
+		if i >= l {
+			panic("Length mismatch on array field")
+		}
+		kind := d.readByte()
+		for d.i < end && d.in[d.i] != '\x00' {
+			d.i++
+		}
+		if d.i >= end {
+			corrupted()
+		}
+		d.i++
+		d.readElemTo(out.Index(i), kind)
+		if d.i >= end {
+			corrupted()
+		}
+		i++
+	}
+	if i != l {
+		panic("Length mismatch on array field")
+	}
+	d.i++ // '\x00'
+	if d.i != end {
+		corrupted()
+	}
+}
+
+func (d *decoder) readSliceDoc(t reflect.Type) interface{} {
+	tmp := make([]reflect.Value, 0, 8)
+	elemType := t.Elem()
+	if elemType == typeRawDocElem {
+		d.dropElem(ElementArray)
+		return reflect.Zero(t).Interface()
+	}
+	if elemType == typeRaw {
+		return d.readSliceOfRaw()
+	}
+
+	end := int(d.readInt32())
+	end += d.i - 4
+	if end <= d.i || end > len(d.in) || d.in[end-1] != '\x00' {
+		corrupted()
+	}
+	for d.in[d.i] != '\x00' {
+		kind := d.readByte()
+		for d.i < end && d.in[d.i] != '\x00' {
+			d.i++
+		}
+		if d.i >= end {
+			corrupted()
+		}
+		d.i++
+		e := reflect.New(elemType).Elem()
+		if d.readElemTo(e, kind) {
+			tmp = append(tmp, e)
+		}
+		if d.i >= end {
+			corrupted()
+		}
+	}
+	d.i++ // '\x00'
+	if d.i != end {
+		corrupted()
+	}
+
+	n := len(tmp)
+	slice := reflect.MakeSlice(t, n, n)
+	for i := 0; i != n; i++ {
+		slice.Index(i).Set(tmp[i])
+	}
+	return slice.Interface()
+}
+
+func BSONElementSize(kind byte, offset int, buffer []byte) (int, error) {
+	switch kind {
+	case ElementFloat64: // Float64
+		return 8, nil
+	case ElementJavaScriptWithoutScope: // JavaScript without scope
+		fallthrough
+	case ElementSymbol: // Symbol
+		fallthrough
+	case ElementString: // UTF-8 string
+		size, err := getSize(offset, buffer)
+		if err != nil {
+			return 0, err
+		}
+		if size < 1 {
+			return 0, errors.New("String size can't be less then one byte")
+		}
+		size += 4
+		if offset+size > len(buffer) {
+			return 0, io.ErrUnexpectedEOF
+		}
+		if buffer[offset+size-1] != 0 {
+			return 0, errors.New("Invalid string: non zero-terminated")
+		}
+		return size, nil
+	case ElementArray: // Array
+		fallthrough
+	case ElementDocument: // Document
+		size, err := getSize(offset, buffer)
+		if err != nil {
+			return 0, err
+		}
+		if size < 5 {
+			return 0, errors.New("Declared document size is too small")
+		}
+		return size, nil
+	case ElementBinary: // Binary
+		size, err := getSize(offset, buffer)
+		if err != nil {
+			return 0, err
+		}
+		if size < 0 {
+			return 0, errors.New("Binary data size can't be negative")
+		}
+		return size + 5, nil
+	case Element06: // Undefined (obsolete, but still seen in the wild)
+		return 0, nil
+	case ElementObjectId: // ObjectId
+		return 12, nil
+	case ElementBool: // Bool
+		return 1, nil
+	case ElementDatetime: // Timestamp
+		return 8, nil
+	case ElementNil: // Nil
+		return 0, nil
+	case ElementRegEx: // RegEx
+		end := offset
+		for i := 0; i < 2; i++ {
+			for end < len(buffer) && buffer[end] != '\x00' {
+				end++
+			}
+			end++
+		}
+		if end > len(buffer) {
+			return 0, io.ErrUnexpectedEOF
+		}
+		return end - offset, nil
+	case ElementDBPointer: // DBPointer
+		size, err := getSize(offset, buffer)
+		if err != nil {
+			return 0, err
+		}
+		if size < 1 {
+			return 0, errors.New("String size can't be less then one byte")
+		}
+		return size + 12 + 4, nil
+	case ElementJavaScriptWithScope: // JavaScript with scope
+		size, err := getSize(offset, buffer)
+		if err != nil {
+			return 0, err
+		}
+		if size < 4+5+5 {
+			return 0, errors.New("Declared document element is too small")
+		}
+		return size, nil
+	case ElementInt32: // Int32
+		return 4, nil
+	case ElementTimestamp: // Mongo-specific timestamp
+		return 8, nil
+	case ElementInt64: // Int64
+		return 8, nil
+	case ElementDecimal128: // Decimal128
+		return 16, nil
+	case ElementMaxKey: // Max key
+		return 0, nil
+	case ElementMinKey: // Min key
+		return 0, nil
+	default:
+		return 0, errors.New(fmt.Sprintf("Unknown element kind (0x%02X)", kind))
+	}
+}
+
+func (d *decoder) readRaw(kind byte) Raw {
+	size, err := BSONElementSize(kind, d.i, d.in)
+	if err != nil {
+		corrupted()
+	}
+	if d.i+size > len(d.in) {
+		corrupted()
+	}
+	d.i += size
+	return Raw{
+		Kind: kind,
+		Data: d.in[d.i-size : d.i],
+	}
+}
+
+func (d *decoder) readSliceOfRaw() interface{} {
+	tmp := make([]Raw, 0, 8)
+	end := int(d.readInt32())
+	end += d.i - 4
+	if end <= d.i || end > len(d.in) || d.in[end-1] != '\x00' {
+		corrupted()
+	}
+	for d.in[d.i] != '\x00' {
+		kind := d.readByte()
+		for d.i < end && d.in[d.i] != '\x00' {
+			d.i++
+		}
+		if d.i >= end {
+			corrupted()
+		}
+		d.i++
+		e := d.readRaw(kind)
+		tmp = append(tmp, e)
+		if d.i >= end {
+			corrupted()
+		}
+	}
+	d.i++ // '\x00'
+	if d.i != end {
+		corrupted()
+	}
+	return tmp
+}
+
+var typeSlice = reflect.TypeOf([]interface{}{})
+var typeIface = typeSlice.Elem()
+
+func (d *decoder) readDocElems(typ reflect.Type) reflect.Value {
+	docType := d.docType
+	d.docType = typ
+	slice := make([]DocElem, 0, 8)
+	d.readDocWith(func(kind byte, name string) {
+		e := DocElem{Name: name}
+		v := reflect.ValueOf(&e.Value)
+		if d.readElemTo(v.Elem(), kind) {
+			slice = append(slice, e)
+		}
+	})
+	slicev := reflect.New(typ).Elem()
+	slicev.Set(reflect.ValueOf(slice))
+	d.docType = docType
+	return slicev
+}
+
+func (d *decoder) readRawDocElems(typ reflect.Type) reflect.Value {
+	docType := d.docType
+	d.docType = typ
+	slice := make([]RawDocElem, 0, 8)
+	d.readDocWith(func(kind byte, name string) {
+		e := RawDocElem{Name: name, Value: d.readRaw(kind)}
+		slice = append(slice, e)
+	})
+	slicev := reflect.New(typ).Elem()
+	slicev.Set(reflect.ValueOf(slice))
+	d.docType = docType
+	return slicev
+}
+
+func (d *decoder) readDocWith(f func(kind byte, name string)) {
+	end := int(d.readInt32())
+	end += d.i - 4
+	if end <= d.i || end > len(d.in) || d.in[end-1] != '\x00' {
+		corrupted()
+	}
+	for d.in[d.i] != '\x00' {
+		kind := d.readByte()
+		name := d.readCStr()
+		if d.i >= end {
+			corrupted()
+		}
+		f(kind, name)
+		if d.i >= end {
+			corrupted()
+		}
+	}
+	d.i++ // '\x00'
+	if d.i != end {
+		corrupted()
+	}
+}
+
+// --------------------------------------------------------------------------
+// Unmarshaling of individual elements within a document.
+func (d *decoder) dropElem(kind byte) {
+	size, err := BSONElementSize(kind, d.i, d.in)
+	if err != nil {
+		corrupted()
+	}
+	if d.i+size > len(d.in) {
+		corrupted()
+	}
+	d.i += size
+}
+
+// Attempt to decode an element from the document and put it into out.
+// If the types are not compatible, the returned ok value will be
+// false and out will be unchanged.
+func (d *decoder) readElemTo(out reflect.Value, kind byte) (good bool) {
+	outt := out.Type()
+
+	if outt == typeRaw {
+		out.Set(reflect.ValueOf(d.readRaw(kind)))
+		return true
+	}
+
+	if outt == typeRawPtr {
+		raw := d.readRaw(kind)
+		out.Set(reflect.ValueOf(&raw))
+		return true
+	}
+
+	if kind == ElementDocument {
+		// Delegate unmarshaling of documents.
+		outt := out.Type()
+		outk := out.Kind()
+		switch outk {
+		case reflect.Interface, reflect.Ptr, reflect.Struct, reflect.Map:
+			d.readDocTo(out)
+			return true
+		}
+		if setterStyle(outt) != setterNone {
+			d.readDocTo(out)
+			return true
+		}
+		if outk == reflect.Slice {
+			switch outt.Elem() {
+			case typeDocElem:
+				out.Set(d.readDocElems(outt))
+			case typeRawDocElem:
+				out.Set(d.readRawDocElems(outt))
+			default:
+				d.dropElem(kind)
+			}
+			return true
+		}
+		d.dropElem(kind)
+		return true
+	}
+
+	if setter := getSetter(outt, out); setter != nil {
+		err := setter.SetBSON(d.readRaw(kind))
+		if err == ErrSetZero {
+			out.Set(reflect.Zero(outt))
+			return true
+		}
+		if err == nil {
+			return true
+		}
+		if _, ok := err.(*TypeError); !ok {
+			panic(err)
+		}
+		return false
+	}
+
+	var in interface{}
+
+	switch kind {
+	case ElementFloat64:
+		in = d.readFloat64()
+	case ElementString:
+		in = d.readStr()
+	case ElementDocument:
+		panic("Can't happen. Handled above.")
+	case ElementArray:
+		outt := out.Type()
+		if setterStyle(outt) != setterNone {
+			// Skip the value so its data is handed to the setter below.
+			d.dropElem(kind)
+			break
+		}
+		for outt.Kind() == reflect.Ptr {
+			outt = outt.Elem()
+		}
+		switch outt.Kind() {
+		case reflect.Array:
+			d.readArrayDocTo(out)
+			return true
+		case reflect.Slice:
+			in = d.readSliceDoc(outt)
+		default:
+			in = d.readSliceDoc(typeSlice)
+		}
+	case ElementBinary:
+		b := d.readBinary()
+		if b.Kind == BinaryGeneric || b.Kind == BinaryBinaryOld {
+			in = b.Data
+		} else {
+			in = b
+		}
+	case Element06: // Undefined (obsolete, but still seen in the wild)
+		in = Undefined
+	case ElementObjectId:
+		in = ObjectId(d.readBytes(12))
+	case ElementBool:
+		in = d.readBool()
+	case ElementDatetime: // Timestamp
+		// MongoDB handles timestamps as milliseconds.
+		i := d.readInt64()
+		if i == -62135596800000 {
+			in = time.Time{} // In UTC for convenience.
+		} else {
+			in = time.Unix(i/1e3, i%1e3*1e6).UTC()
+		}
+	case ElementNil:
+		in = nil
+	case ElementRegEx:
+		in = d.readRegEx()
+	case ElementDBPointer:
+		in = DBPointer{Namespace: d.readStr(), Id: ObjectId(d.readBytes(12))}
+	case ElementJavaScriptWithoutScope:
+		in = JavaScript{Code: d.readStr()}
+	case ElementSymbol:
+		in = Symbol(d.readStr())
+	case ElementJavaScriptWithScope:
+		start := d.i
+		l := int(d.readInt32())
+		js := JavaScript{d.readStr(), make(M)}
+		d.readDocTo(reflect.ValueOf(js.Scope))
+		if d.i != start+l {
+			corrupted()
+		}
+		in = js
+	case ElementInt32:
+		in = int(d.readInt32())
+	case ElementTimestamp: // Mongo-specific timestamp
+		in = MongoTimestamp(d.readInt64())
+	case ElementInt64:
+		switch out.Type() {
+		case typeTimeDuration:
+			in = time.Duration(time.Duration(d.readInt64()) * time.Millisecond)
+		default:
+			in = d.readInt64()
+		}
+	case ElementDecimal128:
+		in = Decimal128{
+			l: uint64(d.readInt64()),
+			h: uint64(d.readInt64()),
+		}
+	case ElementMaxKey:
+		in = MaxKey
+	case ElementMinKey:
+		in = MinKey
+	default:
+		panic(fmt.Sprintf("Unknown element kind (0x%02X)", kind))
+	}
+
+	if in == nil {
+		out.Set(reflect.Zero(outt))
+		return true
+	}
+
+	outk := outt.Kind()
+
+	// Dereference and initialize pointer if necessary.
+	first := true
+	for outk == reflect.Ptr {
+		if !out.IsNil() {
+			out = out.Elem()
+		} else {
+			elem := reflect.New(outt.Elem())
+			if first {
+				// Only set if value is compatible.
+				first = false
+				defer func(out, elem reflect.Value) {
+					if good {
+						out.Set(elem)
+					}
+				}(out, elem)
+			} else {
+				out.Set(elem)
+			}
+			out = elem
+		}
+		outt = out.Type()
+		outk = outt.Kind()
+	}
+
+	inv := reflect.ValueOf(in)
+	if outt == inv.Type() {
+		out.Set(inv)
+		return true
+	}
+
+	switch outk {
+	case reflect.Interface:
+		out.Set(inv)
+		return true
+	case reflect.String:
+		switch inv.Kind() {
+		case reflect.String:
+			out.SetString(inv.String())
+			return true
+		case reflect.Slice:
+			if b, ok := in.([]byte); ok {
+				out.SetString(string(b))
+				return true
+			}
+		case reflect.Int, reflect.Int64:
+			if outt == typeJSONNumber {
+				out.SetString(strconv.FormatInt(inv.Int(), 10))
+				return true
+			}
+		case reflect.Float64:
+			if outt == typeJSONNumber {
+				out.SetString(strconv.FormatFloat(inv.Float(), 'f', -1, 64))
+				return true
+			}
+		}
+	case reflect.Slice, reflect.Array:
+		// Remember, array (0x04) slices are built with the correct
+		// element type.  If we are here, must be a cross BSON kind
+		// conversion (e.g. 0x05 unmarshalling on string).
+		if outt.Elem().Kind() != reflect.Uint8 {
+			break
+		}
+		switch inv.Kind() {
+		case reflect.String:
+			slice := []byte(inv.String())
+			out.Set(reflect.ValueOf(slice))
+			return true
+		case reflect.Slice:
+			switch outt.Kind() {
+			case reflect.Array:
+				reflect.Copy(out, inv)
+			case reflect.Slice:
+				out.SetBytes(inv.Bytes())
+			}
+			return true
+		}
+	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
+		switch inv.Kind() {
+		case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
+			out.SetInt(inv.Int())
+			return true
+		case reflect.Float32, reflect.Float64:
+			out.SetInt(int64(inv.Float()))
+			return true
+		case reflect.Bool:
+			if inv.Bool() {
+				out.SetInt(1)
+			} else {
+				out.SetInt(0)
+			}
+			return true
+		case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
+			panic("can't happen: no uint types in BSON (!?)")
+		}
+	case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
+		switch inv.Kind() {
+		case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
+			out.SetUint(uint64(inv.Int()))
+			return true
+		case reflect.Float32, reflect.Float64:
+			out.SetUint(uint64(inv.Float()))
+			return true
+		case reflect.Bool:
+			if inv.Bool() {
+				out.SetUint(1)
+			} else {
+				out.SetUint(0)
+			}
+			return true
+		case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
+			panic("Can't happen. No uint types in BSON.")
+		}
+	case reflect.Float32, reflect.Float64:
+		switch inv.Kind() {
+		case reflect.Float32, reflect.Float64:
+			out.SetFloat(inv.Float())
+			return true
+		case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
+			out.SetFloat(float64(inv.Int()))
+			return true
+		case reflect.Bool:
+			if inv.Bool() {
+				out.SetFloat(1)
+			} else {
+				out.SetFloat(0)
+			}
+			return true
+		case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
+			panic("Can't happen. No uint types in BSON?")
+		}
+	case reflect.Bool:
+		switch inv.Kind() {
+		case reflect.Bool:
+			out.SetBool(inv.Bool())
+			return true
+		case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
+			out.SetBool(inv.Int() != 0)
+			return true
+		case reflect.Float32, reflect.Float64:
+			out.SetBool(inv.Float() != 0)
+			return true
+		case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
+			panic("Can't happen. No uint types in BSON?")
+		}
+	case reflect.Struct:
+		if outt == typeURL && inv.Kind() == reflect.String {
+			u, err := url.Parse(inv.String())
+			if err != nil {
+				panic(err)
+			}
+			out.Set(reflect.ValueOf(u).Elem())
+			return true
+		}
+		if outt == typeBinary {
+			if b, ok := in.([]byte); ok {
+				out.Set(reflect.ValueOf(Binary{Data: b}))
+				return true
+			}
+		}
+	}
+
+	return false
+}
+
+// --------------------------------------------------------------------------
+// Parsers of basic types.
+
+func (d *decoder) readRegEx() RegEx {
+	re := RegEx{}
+	re.Pattern = d.readCStr()
+	re.Options = d.readCStr()
+	return re
+}
+
+func (d *decoder) readBinary() Binary {
+	l := d.readInt32()
+	b := Binary{}
+	b.Kind = d.readByte()
+	if b.Kind == BinaryBinaryOld && l > 4 {
+		// Weird obsolete format with redundant length.
+		rl := d.readInt32()
+		if rl != l-4 {
+			corrupted()
+		}
+		l = rl
+	}
+	b.Data = d.readBytes(l)
+	return b
+}
+
+func (d *decoder) readStr() string {
+	l := d.readInt32()
+	b := d.readBytes(l - 1)
+	if d.readByte() != '\x00' {
+		corrupted()
+	}
+	return string(b)
+}
+
+func (d *decoder) readCStr() string {
+	start := d.i
+	end := start
+	l := len(d.in)
+	for ; end != l; end++ {
+		if d.in[end] == '\x00' {
+			break
+		}
+	}
+	d.i = end + 1
+	if d.i > l {
+		corrupted()
+	}
+	return string(d.in[start:end])
+}
+
+func (d *decoder) readBool() bool {
+	b := d.readByte()
+	if b == 0 {
+		return false
+	}
+	if b == 1 {
+		return true
+	}
+	panic(fmt.Sprintf("encoded boolean must be 1 or 0, found %d", b))
+}
+
+func (d *decoder) readFloat64() float64 {
+	return math.Float64frombits(uint64(d.readInt64()))
+}
+
+func (d *decoder) readInt32() int32 {
+	b := d.readBytes(4)
+	return int32((uint32(b[0]) << 0) |
+		(uint32(b[1]) << 8) |
+		(uint32(b[2]) << 16) |
+		(uint32(b[3]) << 24))
+}
+
+func getSize(offset int, b []byte) (int, error) {
+	if offset+4 > len(b) {
+		return 0, io.ErrUnexpectedEOF
+	}
+	return int((uint32(b[offset]) << 0) |
+		(uint32(b[offset+1]) << 8) |
+		(uint32(b[offset+2]) << 16) |
+		(uint32(b[offset+3]) << 24)), nil
+}
+
+func (d *decoder) readInt64() int64 {
+	b := d.readBytes(8)
+	return int64((uint64(b[0]) << 0) |
+		(uint64(b[1]) << 8) |
+		(uint64(b[2]) << 16) |
+		(uint64(b[3]) << 24) |
+		(uint64(b[4]) << 32) |
+		(uint64(b[5]) << 40) |
+		(uint64(b[6]) << 48) |
+		(uint64(b[7]) << 56))
+}
+
+func (d *decoder) readByte() byte {
+	i := d.i
+	d.i++
+	if d.i > len(d.in) {
+		corrupted()
+	}
+	return d.in[i]
+}
+
+func (d *decoder) readBytes(length int32) []byte {
+	if length < 0 {
+		corrupted()
+	}
+	start := d.i
+	d.i += int(length)
+	if d.i < start || d.i > len(d.in) {
+		corrupted()
+	}
+	return d.in[start : start+int(length)]
+}