Initial checkin from CRI-O repo

Signed-off-by: Matthew Heon <matthew.heon@gmail.com>

12 files changed, 3170 insertions, 0 deletions

diff --git a/vendor/github.com/BurntSushi/toml/COPYING b/vendor/github.com/BurntSushi/toml/COPYING
new file mode 100644
index 000000000..5a8e33254
--- /dev/null
+++ b/vendor/github.com/BurntSushi/toml/COPYING
@@ -0,0 +1,14 @@
+            DO WHAT THE FUCK YOU WANT TO PUBLIC LICENSE
+                    Version 2, December 2004
+
+ Copyright (C) 2004 Sam Hocevar <sam@hocevar.net>
+
+ Everyone is permitted to copy and distribute verbatim or modified
+ copies of this license document, and changing it is allowed as long
+ as the name is changed.
+
+            DO WHAT THE FUCK YOU WANT TO PUBLIC LICENSE
+   TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION
+
+  0. You just DO WHAT THE FUCK YOU WANT TO.
+
diff --git a/vendor/github.com/BurntSushi/toml/README.md b/vendor/github.com/BurntSushi/toml/README.md
new file mode 100644
index 000000000..5a5df6370
--- /dev/null
+++ b/vendor/github.com/BurntSushi/toml/README.md
@@ -0,0 +1,220 @@
+## TOML parser and encoder for Go with reflection
+
+TOML stands for Tom's Obvious, Minimal Language. This Go package provides a
+reflection interface similar to Go's standard library `json` and `xml` 
+packages. This package also supports the `encoding.TextUnmarshaler` and
+`encoding.TextMarshaler` interfaces so that you can define custom data 
+representations. (There is an example of this below.)
+
+Spec: https://github.com/mojombo/toml
+
+Compatible with TOML version
+[v0.2.0](https://github.com/toml-lang/toml/blob/master/versions/en/toml-v0.2.0.md)
+
+Documentation: http://godoc.org/github.com/BurntSushi/toml
+
+Installation:
+
+```bash
+go get github.com/BurntSushi/toml
+```
+
+Try the toml validator:
+
+```bash
+go get github.com/BurntSushi/toml/cmd/tomlv
+tomlv some-toml-file.toml
+```
+
+[![Build status](https://api.travis-ci.org/BurntSushi/toml.png)](https://travis-ci.org/BurntSushi/toml)
+
+
+### Testing
+
+This package passes all tests in
+[toml-test](https://github.com/BurntSushi/toml-test) for both the decoder
+and the encoder.
+
+### Examples
+
+This package works similarly to how the Go standard library handles `XML`
+and `JSON`. Namely, data is loaded into Go values via reflection.
+
+For the simplest example, consider some TOML file as just a list of keys
+and values:
+
+```toml
+Age = 25
+Cats = [ "Cauchy", "Plato" ]
+Pi = 3.14
+Perfection = [ 6, 28, 496, 8128 ]
+DOB = 1987-07-05T05:45:00Z
+```
+
+Which could be defined in Go as:
+
+```go
+type Config struct {
+  Age int
+  Cats []string
+  Pi float64
+  Perfection []int
+  DOB time.Time // requires `import time`
+}
+```
+
+And then decoded with:
+
+```go
+var conf Config
+if _, err := toml.Decode(tomlData, &conf); err != nil {
+  // handle error
+}
+```
+
+You can also use struct tags if your struct field name doesn't map to a TOML
+key value directly:
+
+```toml
+some_key_NAME = "wat"
+```
+
+```go
+type TOML struct {
+  ObscureKey string `toml:"some_key_NAME"`
+}
+```
+
+### Using the `encoding.TextUnmarshaler` interface
+
+Here's an example that automatically parses duration strings into 
+`time.Duration` values:
+
+```toml
+[[song]]
+name = "Thunder Road"
+duration = "4m49s"
+
+[[song]]
+name = "Stairway to Heaven"
+duration = "8m03s"
+```
+
+Which can be decoded with:
+
+```go
+type song struct {
+  Name     string
+  Duration duration
+}
+type songs struct {
+  Song []song
+}
+var favorites songs
+if _, err := toml.Decode(blob, &favorites); err != nil {
+  log.Fatal(err)
+}
+
+for _, s := range favorites.Song {
+  fmt.Printf("%s (%s)\n", s.Name, s.Duration)
+}
+```
+
+And you'll also need a `duration` type that satisfies the 
+`encoding.TextUnmarshaler` interface:
+
+```go
+type duration struct {
+	time.Duration
+}
+
+func (d *duration) UnmarshalText(text []byte) error {
+	var err error
+	d.Duration, err = time.ParseDuration(string(text))
+	return err
+}
+```
+
+### More complex usage
+
+Here's an example of how to load the example from the official spec page:
+
+```toml
+# This is a TOML document. Boom.
+
+title = "TOML Example"
+
+[owner]
+name = "Tom Preston-Werner"
+organization = "GitHub"
+bio = "GitHub Cofounder & CEO\nLikes tater tots and beer."
+dob = 1979-05-27T07:32:00Z # First class dates? Why not?
+
+[database]
+server = "192.168.1.1"
+ports = [ 8001, 8001, 8002 ]
+connection_max = 5000
+enabled = true
+
+[servers]
+
+  # You can indent as you please. Tabs or spaces. TOML don't care.
+  [servers.alpha]
+  ip = "10.0.0.1"
+  dc = "eqdc10"
+
+  [servers.beta]
+  ip = "10.0.0.2"
+  dc = "eqdc10"
+
+[clients]
+data = [ ["gamma", "delta"], [1, 2] ] # just an update to make sure parsers support it
+
+# Line breaks are OK when inside arrays
+hosts = [
+  "alpha",
+  "omega"
+]
+```
+
+And the corresponding Go types are:
+
+```go
+type tomlConfig struct {
+	Title string
+	Owner ownerInfo
+	DB database `toml:"database"`
+	Servers map[string]server
+	Clients clients
+}
+
+type ownerInfo struct {
+	Name string
+	Org string `toml:"organization"`
+	Bio string
+	DOB time.Time
+}
+
+type database struct {
+	Server string
+	Ports []int
+	ConnMax int `toml:"connection_max"`
+	Enabled bool
+}
+
+type server struct {
+	IP string
+	DC string
+}
+
+type clients struct {
+	Data [][]interface{}
+	Hosts []string
+}
+```
+
+Note that a case insensitive match will be tried if an exact match can't be
+found.
+
+A working example of the above can be found in `_examples/example.{go,toml}`.
+
diff --git a/vendor/github.com/BurntSushi/toml/decode.go b/vendor/github.com/BurntSushi/toml/decode.go
new file mode 100644
index 000000000..c26b00c01
--- /dev/null
+++ b/vendor/github.com/BurntSushi/toml/decode.go
@@ -0,0 +1,505 @@
+package toml
+
+import (
+	"fmt"
+	"io"
+	"io/ioutil"
+	"math"
+	"reflect"
+	"strings"
+	"time"
+)
+
+var e = fmt.Errorf
+
+// Unmarshaler is the interface implemented by objects that can unmarshal a
+// TOML description of themselves.
+type Unmarshaler interface {
+	UnmarshalTOML(interface{}) error
+}
+
+// Unmarshal decodes the contents of `p` in TOML format into a pointer `v`.
+func Unmarshal(p []byte, v interface{}) error {
+	_, err := Decode(string(p), v)
+	return err
+}
+
+// Primitive is a TOML value that hasn't been decoded into a Go value.
+// When using the various `Decode*` functions, the type `Primitive` may
+// be given to any value, and its decoding will be delayed.
+//
+// A `Primitive` value can be decoded using the `PrimitiveDecode` function.
+//
+// The underlying representation of a `Primitive` value is subject to change.
+// Do not rely on it.
+//
+// N.B. Primitive values are still parsed, so using them will only avoid
+// the overhead of reflection. They can be useful when you don't know the
+// exact type of TOML data until run time.
+type Primitive struct {
+	undecoded interface{}
+	context   Key
+}
+
+// DEPRECATED!
+//
+// Use MetaData.PrimitiveDecode instead.
+func PrimitiveDecode(primValue Primitive, v interface{}) error {
+	md := MetaData{decoded: make(map[string]bool)}
+	return md.unify(primValue.undecoded, rvalue(v))
+}
+
+// PrimitiveDecode is just like the other `Decode*` functions, except it
+// decodes a TOML value that has already been parsed. Valid primitive values
+// can *only* be obtained from values filled by the decoder functions,
+// including this method. (i.e., `v` may contain more `Primitive`
+// values.)
+//
+// Meta data for primitive values is included in the meta data returned by
+// the `Decode*` functions with one exception: keys returned by the Undecoded
+// method will only reflect keys that were decoded. Namely, any keys hidden
+// behind a Primitive will be considered undecoded. Executing this method will
+// update the undecoded keys in the meta data. (See the example.)
+func (md *MetaData) PrimitiveDecode(primValue Primitive, v interface{}) error {
+	md.context = primValue.context
+	defer func() { md.context = nil }()
+	return md.unify(primValue.undecoded, rvalue(v))
+}
+
+// Decode will decode the contents of `data` in TOML format into a pointer
+// `v`.
+//
+// TOML hashes correspond to Go structs or maps. (Dealer's choice. They can be
+// used interchangeably.)
+//
+// TOML arrays of tables correspond to either a slice of structs or a slice
+// of maps.
+//
+// TOML datetimes correspond to Go `time.Time` values.
+//
+// All other TOML types (float, string, int, bool and array) correspond
+// to the obvious Go types.
+//
+// An exception to the above rules is if a type implements the
+// encoding.TextUnmarshaler interface. In this case, any primitive TOML value
+// (floats, strings, integers, booleans and datetimes) will be converted to
+// a byte string and given to the value's UnmarshalText method. See the
+// Unmarshaler example for a demonstration with time duration strings.
+//
+// Key mapping
+//
+// TOML keys can map to either keys in a Go map or field names in a Go
+// struct. The special `toml` struct tag may be used to map TOML keys to
+// struct fields that don't match the key name exactly. (See the example.)
+// A case insensitive match to struct names will be tried if an exact match
+// can't be found.
+//
+// The mapping between TOML values and Go values is loose. That is, there
+// may exist TOML values that cannot be placed into your representation, and
+// there may be parts of your representation that do not correspond to
+// TOML values. This loose mapping can be made stricter by using the IsDefined
+// and/or Undecoded methods on the MetaData returned.
+//
+// This decoder will not handle cyclic types. If a cyclic type is passed,
+// `Decode` will not terminate.
+func Decode(data string, v interface{}) (MetaData, error) {
+	p, err := parse(data)
+	if err != nil {
+		return MetaData{}, err
+	}
+	md := MetaData{
+		p.mapping, p.types, p.ordered,
+		make(map[string]bool, len(p.ordered)), nil,
+	}
+	return md, md.unify(p.mapping, rvalue(v))
+}
+
+// DecodeFile is just like Decode, except it will automatically read the
+// contents of the file at `fpath` and decode it for you.
+func DecodeFile(fpath string, v interface{}) (MetaData, error) {
+	bs, err := ioutil.ReadFile(fpath)
+	if err != nil {
+		return MetaData{}, err
+	}
+	return Decode(string(bs), v)
+}
+
+// DecodeReader is just like Decode, except it will consume all bytes
+// from the reader and decode it for you.
+func DecodeReader(r io.Reader, v interface{}) (MetaData, error) {
+	bs, err := ioutil.ReadAll(r)
+	if err != nil {
+		return MetaData{}, err
+	}
+	return Decode(string(bs), v)
+}
+
+// unify performs a sort of type unification based on the structure of `rv`,
+// which is the client representation.
+//
+// Any type mismatch produces an error. Finding a type that we don't know
+// how to handle produces an unsupported type error.
+func (md *MetaData) unify(data interface{}, rv reflect.Value) error {
+
+	// Special case. Look for a `Primitive` value.
+	if rv.Type() == reflect.TypeOf((*Primitive)(nil)).Elem() {
+		// Save the undecoded data and the key context into the primitive
+		// value.
+		context := make(Key, len(md.context))
+		copy(context, md.context)
+		rv.Set(reflect.ValueOf(Primitive{
+			undecoded: data,
+			context:   context,
+		}))
+		return nil
+	}
+
+	// Special case. Unmarshaler Interface support.
+	if rv.CanAddr() {
+		if v, ok := rv.Addr().Interface().(Unmarshaler); ok {
+			return v.UnmarshalTOML(data)
+		}
+	}
+
+	// Special case. Handle time.Time values specifically.
+	// TODO: Remove this code when we decide to drop support for Go 1.1.
+	// This isn't necessary in Go 1.2 because time.Time satisfies the encoding
+	// interfaces.
+	if rv.Type().AssignableTo(rvalue(time.Time{}).Type()) {
+		return md.unifyDatetime(data, rv)
+	}
+
+	// Special case. Look for a value satisfying the TextUnmarshaler interface.
+	if v, ok := rv.Interface().(TextUnmarshaler); ok {
+		return md.unifyText(data, v)
+	}
+	// BUG(burntsushi)
+	// The behavior here is incorrect whenever a Go type satisfies the
+	// encoding.TextUnmarshaler interface but also corresponds to a TOML
+	// hash or array. In particular, the unmarshaler should only be applied
+	// to primitive TOML values. But at this point, it will be applied to
+	// all kinds of values and produce an incorrect error whenever those values
+	// are hashes or arrays (including arrays of tables).
+
+	k := rv.Kind()
+
+	// laziness
+	if k >= reflect.Int && k <= reflect.Uint64 {
+		return md.unifyInt(data, rv)
+	}
+	switch k {
+	case reflect.Ptr:
+		elem := reflect.New(rv.Type().Elem())
+		err := md.unify(data, reflect.Indirect(elem))
+		if err != nil {
+			return err
+		}
+		rv.Set(elem)
+		return nil
+	case reflect.Struct:
+		return md.unifyStruct(data, rv)
+	case reflect.Map:
+		return md.unifyMap(data, rv)
+	case reflect.Array:
+		return md.unifyArray(data, rv)
+	case reflect.Slice:
+		return md.unifySlice(data, rv)
+	case reflect.String:
+		return md.unifyString(data, rv)
+	case reflect.Bool:
+		return md.unifyBool(data, rv)
+	case reflect.Interface:
+		// we only support empty interfaces.
+		if rv.NumMethod() > 0 {
+			return e("Unsupported type '%s'.", rv.Kind())
+		}
+		return md.unifyAnything(data, rv)
+	case reflect.Float32:
+		fallthrough
+	case reflect.Float64:
+		return md.unifyFloat64(data, rv)
+	}
+	return e("Unsupported type '%s'.", rv.Kind())
+}
+
+func (md *MetaData) unifyStruct(mapping interface{}, rv reflect.Value) error {
+	tmap, ok := mapping.(map[string]interface{})
+	if !ok {
+		if mapping == nil {
+			return nil
+		}
+		return mismatch(rv, "map", mapping)
+	}
+
+	for key, datum := range tmap {
+		var f *field
+		fields := cachedTypeFields(rv.Type())
+		for i := range fields {
+			ff := &fields[i]
+			if ff.name == key {
+				f = ff
+				break
+			}
+			if f == nil && strings.EqualFold(ff.name, key) {
+				f = ff
+			}
+		}
+		if f != nil {
+			subv := rv
+			for _, i := range f.index {
+				subv = indirect(subv.Field(i))
+			}
+			if isUnifiable(subv) {
+				md.decoded[md.context.add(key).String()] = true
+				md.context = append(md.context, key)
+				if err := md.unify(datum, subv); err != nil {
+					return e("Type mismatch for '%s.%s': %s",
+						rv.Type().String(), f.name, err)
+				}
+				md.context = md.context[0 : len(md.context)-1]
+			} else if f.name != "" {
+				// Bad user! No soup for you!
+				return e("Field '%s.%s' is unexported, and therefore cannot "+
+					"be loaded with reflection.", rv.Type().String(), f.name)
+			}
+		}
+	}
+	return nil
+}
+
+func (md *MetaData) unifyMap(mapping interface{}, rv reflect.Value) error {
+	tmap, ok := mapping.(map[string]interface{})
+	if !ok {
+		if tmap == nil {
+			return nil
+		}
+		return badtype("map", mapping)
+	}
+	if rv.IsNil() {
+		rv.Set(reflect.MakeMap(rv.Type()))
+	}
+	for k, v := range tmap {
+		md.decoded[md.context.add(k).String()] = true
+		md.context = append(md.context, k)
+
+		rvkey := indirect(reflect.New(rv.Type().Key()))
+		rvval := reflect.Indirect(reflect.New(rv.Type().Elem()))
+		if err := md.unify(v, rvval); err != nil {
+			return err
+		}
+		md.context = md.context[0 : len(md.context)-1]
+
+		rvkey.SetString(k)
+		rv.SetMapIndex(rvkey, rvval)
+	}
+	return nil
+}
+
+func (md *MetaData) unifyArray(data interface{}, rv reflect.Value) error {
+	datav := reflect.ValueOf(data)
+	if datav.Kind() != reflect.Slice {
+		if !datav.IsValid() {
+			return nil
+		}
+		return badtype("slice", data)
+	}
+	sliceLen := datav.Len()
+	if sliceLen != rv.Len() {
+		return e("expected array length %d; got TOML array of length %d",
+			rv.Len(), sliceLen)
+	}
+	return md.unifySliceArray(datav, rv)
+}
+
+func (md *MetaData) unifySlice(data interface{}, rv reflect.Value) error {
+	datav := reflect.ValueOf(data)
+	if datav.Kind() != reflect.Slice {
+		if !datav.IsValid() {
+			return nil
+		}
+		return badtype("slice", data)
+	}
+	n := datav.Len()
+	if rv.IsNil() || rv.Cap() < n {
+		rv.Set(reflect.MakeSlice(rv.Type(), n, n))
+	}
+	rv.SetLen(n)
+	return md.unifySliceArray(datav, rv)
+}
+
+func (md *MetaData) unifySliceArray(data, rv reflect.Value) error {
+	sliceLen := data.Len()
+	for i := 0; i < sliceLen; i++ {
+		v := data.Index(i).Interface()
+		sliceval := indirect(rv.Index(i))
+		if err := md.unify(v, sliceval); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func (md *MetaData) unifyDatetime(data interface{}, rv reflect.Value) error {
+	if _, ok := data.(time.Time); ok {
+		rv.Set(reflect.ValueOf(data))
+		return nil
+	}
+	return badtype("time.Time", data)
+}
+
+func (md *MetaData) unifyString(data interface{}, rv reflect.Value) error {
+	if s, ok := data.(string); ok {
+		rv.SetString(s)
+		return nil
+	}
+	return badtype("string", data)
+}
+
+func (md *MetaData) unifyFloat64(data interface{}, rv reflect.Value) error {
+	if num, ok := data.(float64); ok {
+		switch rv.Kind() {
+		case reflect.Float32:
+			fallthrough
+		case reflect.Float64:
+			rv.SetFloat(num)
+		default:
+			panic("bug")
+		}
+		return nil
+	}
+	return badtype("float", data)
+}
+
+func (md *MetaData) unifyInt(data interface{}, rv reflect.Value) error {
+	if num, ok := data.(int64); ok {
+		if rv.Kind() >= reflect.Int && rv.Kind() <= reflect.Int64 {
+			switch rv.Kind() {
+			case reflect.Int, reflect.Int64:
+				// No bounds checking necessary.
+			case reflect.Int8:
+				if num < math.MinInt8 || num > math.MaxInt8 {
+					return e("Value '%d' is out of range for int8.", num)
+				}
+			case reflect.Int16:
+				if num < math.MinInt16 || num > math.MaxInt16 {
+					return e("Value '%d' is out of range for int16.", num)
+				}
+			case reflect.Int32:
+				if num < math.MinInt32 || num > math.MaxInt32 {
+					return e("Value '%d' is out of range for int32.", num)
+				}
+			}
+			rv.SetInt(num)
+		} else if rv.Kind() >= reflect.Uint && rv.Kind() <= reflect.Uint64 {
+			unum := uint64(num)
+			switch rv.Kind() {
+			case reflect.Uint, reflect.Uint64:
+				// No bounds checking necessary.
+			case reflect.Uint8:
+				if num < 0 || unum > math.MaxUint8 {
+					return e("Value '%d' is out of range for uint8.", num)
+				}
+			case reflect.Uint16:
+				if num < 0 || unum > math.MaxUint16 {
+					return e("Value '%d' is out of range for uint16.", num)
+				}
+			case reflect.Uint32:
+				if num < 0 || unum > math.MaxUint32 {
+					return e("Value '%d' is out of range for uint32.", num)
+				}
+			}
+			rv.SetUint(unum)
+		} else {
+			panic("unreachable")
+		}
+		return nil
+	}
+	return badtype("integer", data)
+}
+
+func (md *MetaData) unifyBool(data interface{}, rv reflect.Value) error {
+	if b, ok := data.(bool); ok {
+		rv.SetBool(b)
+		return nil
+	}
+	return badtype("boolean", data)
+}
+
+func (md *MetaData) unifyAnything(data interface{}, rv reflect.Value) error {
+	rv.Set(reflect.ValueOf(data))
+	return nil
+}
+
+func (md *MetaData) unifyText(data interface{}, v TextUnmarshaler) error {
+	var s string
+	switch sdata := data.(type) {
+	case TextMarshaler:
+		text, err := sdata.MarshalText()
+		if err != nil {
+			return err
+		}
+		s = string(text)
+	case fmt.Stringer:
+		s = sdata.String()
+	case string:
+		s = sdata
+	case bool:
+		s = fmt.Sprintf("%v", sdata)
+	case int64:
+		s = fmt.Sprintf("%d", sdata)
+	case float64:
+		s = fmt.Sprintf("%f", sdata)
+	default:
+		return badtype("primitive (string-like)", data)
+	}
+	if err := v.UnmarshalText([]byte(s)); err != nil {
+		return err
+	}
+	return nil
+}
+
+// rvalue returns a reflect.Value of `v`. All pointers are resolved.
+func rvalue(v interface{}) reflect.Value {
+	return indirect(reflect.ValueOf(v))
+}
+
+// indirect returns the value pointed to by a pointer.
+// Pointers are followed until the value is not a pointer.
+// New values are allocated for each nil pointer.
+//
+// An exception to this rule is if the value satisfies an interface of
+// interest to us (like encoding.TextUnmarshaler).
+func indirect(v reflect.Value) reflect.Value {
+	if v.Kind() != reflect.Ptr {
+		if v.CanAddr() {
+			pv := v.Addr()
+			if _, ok := pv.Interface().(TextUnmarshaler); ok {
+				return pv
+			}
+		}
+		return v
+	}
+	if v.IsNil() {
+		v.Set(reflect.New(v.Type().Elem()))
+	}
+	return indirect(reflect.Indirect(v))
+}
+
+func isUnifiable(rv reflect.Value) bool {
+	if rv.CanSet() {
+		return true
+	}
+	if _, ok := rv.Interface().(TextUnmarshaler); ok {
+		return true
+	}
+	return false
+}
+
+func badtype(expected string, data interface{}) error {
+	return e("Expected %s but found '%T'.", expected, data)
+}
+
+func mismatch(user reflect.Value, expected string, data interface{}) error {
+	return e("Type mismatch for %s. Expected %s but found '%T'.",
+		user.Type().String(), expected, data)
+}
diff --git a/vendor/github.com/BurntSushi/toml/decode_meta.go b/vendor/github.com/BurntSushi/toml/decode_meta.go
new file mode 100644
index 000000000..ef6f545fa
--- /dev/null
+++ b/vendor/github.com/BurntSushi/toml/decode_meta.go
@@ -0,0 +1,122 @@
+package toml
+
+import "strings"
+
+// MetaData allows access to meta information about TOML data that may not
+// be inferrable via reflection. In particular, whether a key has been defined
+// and the TOML type of a key.
+type MetaData struct {
+	mapping map[string]interface{}
+	types   map[string]tomlType
+	keys    []Key
+	decoded map[string]bool
+	context Key // Used only during decoding.
+}
+
+// IsDefined returns true if the key given exists in the TOML data. The key
+// should be specified hierarchially. e.g.,
+//
+//	// access the TOML key 'a.b.c'
+//	IsDefined("a", "b", "c")
+//
+// IsDefined will return false if an empty key given. Keys are case sensitive.
+func (md *MetaData) IsDefined(key ...string) bool {
+	if len(key) == 0 {
+		return false
+	}
+
+	var hash map[string]interface{}
+	var ok bool
+	var hashOrVal interface{} = md.mapping
+	for _, k := range key {
+		if hash, ok = hashOrVal.(map[string]interface{}); !ok {
+			return false
+		}
+		if hashOrVal, ok = hash[k]; !ok {
+			return false
+		}
+	}
+	return true
+}
+
+// Type returns a string representation of the type of the key specified.
+//
+// Type will return the empty string if given an empty key or a key that
+// does not exist. Keys are case sensitive.
+func (md *MetaData) Type(key ...string) string {
+	fullkey := strings.Join(key, ".")
+	if typ, ok := md.types[fullkey]; ok {
+		return typ.typeString()
+	}
+	return ""
+}
+
+// Key is the type of any TOML key, including key groups. Use (MetaData).Keys
+// to get values of this type.
+type Key []string
+
+func (k Key) String() string {
+	return strings.Join(k, ".")
+}
+
+func (k Key) maybeQuotedAll() string {
+	var ss []string
+	for i := range k {
+		ss = append(ss, k.maybeQuoted(i))
+	}
+	return strings.Join(ss, ".")
+}
+
+func (k Key) maybeQuoted(i int) string {
+	quote := false
+	for _, c := range k[i] {
+		if !isBareKeyChar(c) {
+			quote = true
+			break
+		}
+	}
+	if quote {
+		return "\"" + strings.Replace(k[i], "\"", "\\\"", -1) + "\""
+	} else {
+		return k[i]
+	}
+}
+
+func (k Key) add(piece string) Key {
+	newKey := make(Key, len(k)+1)
+	copy(newKey, k)
+	newKey[len(k)] = piece
+	return newKey
+}
+
+// Keys returns a slice of every key in the TOML data, including key groups.
+// Each key is itself a slice, where the first element is the top of the
+// hierarchy and the last is the most specific.
+//
+// The list will have the same order as the keys appeared in the TOML data.
+//
+// All keys returned are non-empty.
+func (md *MetaData) Keys() []Key {
+	return md.keys
+}
+
+// Undecoded returns all keys that have not been decoded in the order in which
+// they appear in the original TOML document.
+//
+// This includes keys that haven't been decoded because of a Primitive value.
+// Once the Primitive value is decoded, the keys will be considered decoded.
+//
+// Also note that decoding into an empty interface will result in no decoding,
+// and so no keys will be considered decoded.
+//
+// In this sense, the Undecoded keys correspond to keys in the TOML document
+// that do not have a concrete type in your representation.
+func (md *MetaData) Undecoded() []Key {
+	undecoded := make([]Key, 0, len(md.keys))
+	for _, key := range md.keys {
+		if !md.decoded[key.String()] {
+			undecoded = append(undecoded, key)
+		}
+	}
+	return undecoded
+}
diff --git a/vendor/github.com/BurntSushi/toml/doc.go b/vendor/github.com/BurntSushi/toml/doc.go
new file mode 100644
index 000000000..fe2680004
--- /dev/null
+++ b/vendor/github.com/BurntSushi/toml/doc.go
@@ -0,0 +1,27 @@
+/*
+Package toml provides facilities for decoding and encoding TOML configuration
+files via reflection. There is also support for delaying decoding with
+the Primitive type, and querying the set of keys in a TOML document with the
+MetaData type.
+
+The specification implemented: https://github.com/mojombo/toml
+
+The sub-command github.com/BurntSushi/toml/cmd/tomlv can be used to verify
+whether a file is a valid TOML document. It can also be used to print the
+type of each key in a TOML document.
+
+Testing
+
+There are two important types of tests used for this package. The first is
+contained inside '*_test.go' files and uses the standard Go unit testing
+framework. These tests are primarily devoted to holistically testing the
+decoder and encoder.
+
+The second type of testing is used to verify the implementation's adherence
+to the TOML specification. These tests have been factored into their own
+project: https://github.com/BurntSushi/toml-test
+
+The reason the tests are in a separate project is so that they can be used by
+any implementation of TOML. Namely, it is language agnostic.
+*/
+package toml
diff --git a/vendor/github.com/BurntSushi/toml/encode.go b/vendor/github.com/BurntSushi/toml/encode.go
new file mode 100644
index 000000000..4e4c97aed
--- /dev/null
+++ b/vendor/github.com/BurntSushi/toml/encode.go
@@ -0,0 +1,549 @@
+package toml
+
+import (
+	"bufio"
+	"errors"
+	"fmt"
+	"io"
+	"reflect"
+	"sort"
+	"strconv"
+	"strings"
+	"time"
+)
+
+type tomlEncodeError struct{ error }
+
+var (
+	errArrayMixedElementTypes = errors.New(
+		"can't encode array with mixed element types")
+	errArrayNilElement = errors.New(
+		"can't encode array with nil element")
+	errNonString = errors.New(
+		"can't encode a map with non-string key type")
+	errAnonNonStruct = errors.New(
+		"can't encode an anonymous field that is not a struct")
+	errArrayNoTable = errors.New(
+		"TOML array element can't contain a table")
+	errNoKey = errors.New(
+		"top-level values must be a Go map or struct")
+	errAnything = errors.New("") // used in testing
+)
+
+var quotedReplacer = strings.NewReplacer(
+	"\t", "\\t",
+	"\n", "\\n",
+	"\r", "\\r",
+	"\"", "\\\"",
+	"\\", "\\\\",
+)
+
+// Encoder controls the encoding of Go values to a TOML document to some
+// io.Writer.
+//
+// The indentation level can be controlled with the Indent field.
+type Encoder struct {
+	// A single indentation level. By default it is two spaces.
+	Indent string
+
+	// hasWritten is whether we have written any output to w yet.
+	hasWritten bool
+	w          *bufio.Writer
+}
+
+// NewEncoder returns a TOML encoder that encodes Go values to the io.Writer
+// given. By default, a single indentation level is 2 spaces.
+func NewEncoder(w io.Writer) *Encoder {
+	return &Encoder{
+		w:      bufio.NewWriter(w),
+		Indent: "  ",
+	}
+}
+
+// Encode writes a TOML representation of the Go value to the underlying
+// io.Writer. If the value given cannot be encoded to a valid TOML document,
+// then an error is returned.
+//
+// The mapping between Go values and TOML values should be precisely the same
+// as for the Decode* functions. Similarly, the TextMarshaler interface is
+// supported by encoding the resulting bytes as strings. (If you want to write
+// arbitrary binary data then you will need to use something like base64 since
+// TOML does not have any binary types.)
+//
+// When encoding TOML hashes (i.e., Go maps or structs), keys without any
+// sub-hashes are encoded first.
+//
+// If a Go map is encoded, then its keys are sorted alphabetically for
+// deterministic output. More control over this behavior may be provided if
+// there is demand for it.
+//
+// Encoding Go values without a corresponding TOML representation---like map
+// types with non-string keys---will cause an error to be returned. Similarly
+// for mixed arrays/slices, arrays/slices with nil elements, embedded
+// non-struct types and nested slices containing maps or structs.
+// (e.g., [][]map[string]string is not allowed but []map[string]string is OK
+// and so is []map[string][]string.)
+func (enc *Encoder) Encode(v interface{}) error {
+	rv := eindirect(reflect.ValueOf(v))
+	if err := enc.safeEncode(Key([]string{}), rv); err != nil {
+		return err
+	}
+	return enc.w.Flush()
+}
+
+func (enc *Encoder) safeEncode(key Key, rv reflect.Value) (err error) {
+	defer func() {
+		if r := recover(); r != nil {
+			if terr, ok := r.(tomlEncodeError); ok {
+				err = terr.error
+				return
+			}
+			panic(r)
+		}
+	}()
+	enc.encode(key, rv)
+	return nil
+}
+
+func (enc *Encoder) encode(key Key, rv reflect.Value) {
+	// Special case. Time needs to be in ISO8601 format.
+	// Special case. If we can marshal the type to text, then we used that.
+	// Basically, this prevents the encoder for handling these types as
+	// generic structs (or whatever the underlying type of a TextMarshaler is).
+	switch rv.Interface().(type) {
+	case time.Time, TextMarshaler:
+		enc.keyEqElement(key, rv)
+		return
+	}
+
+	k := rv.Kind()
+	switch k {
+	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32,
+		reflect.Int64,
+		reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32,
+		reflect.Uint64,
+		reflect.Float32, reflect.Float64, reflect.String, reflect.Bool:
+		enc.keyEqElement(key, rv)
+	case reflect.Array, reflect.Slice:
+		if typeEqual(tomlArrayHash, tomlTypeOfGo(rv)) {
+			enc.eArrayOfTables(key, rv)
+		} else {
+			enc.keyEqElement(key, rv)
+		}
+	case reflect.Interface:
+		if rv.IsNil() {
+			return
+		}
+		enc.encode(key, rv.Elem())
+	case reflect.Map:
+		if rv.IsNil() {
+			return
+		}
+		enc.eTable(key, rv)
+	case reflect.Ptr:
+		if rv.IsNil() {
+			return
+		}
+		enc.encode(key, rv.Elem())
+	case reflect.Struct:
+		enc.eTable(key, rv)
+	default:
+		panic(e("Unsupported type for key '%s': %s", key, k))
+	}
+}
+
+// eElement encodes any value that can be an array element (primitives and
+// arrays).
+func (enc *Encoder) eElement(rv reflect.Value) {
+	switch v := rv.Interface().(type) {
+	case time.Time:
+		// Special case time.Time as a primitive. Has to come before
+		// TextMarshaler below because time.Time implements
+		// encoding.TextMarshaler, but we need to always use UTC.
+		enc.wf(v.In(time.FixedZone("UTC", 0)).Format("2006-01-02T15:04:05Z"))
+		return
+	case TextMarshaler:
+		// Special case. Use text marshaler if it's available for this value.
+		if s, err := v.MarshalText(); err != nil {
+			encPanic(err)
+		} else {
+			enc.writeQuoted(string(s))
+		}
+		return
+	}
+	switch rv.Kind() {
+	case reflect.Bool:
+		enc.wf(strconv.FormatBool(rv.Bool()))
+	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32,
+		reflect.Int64:
+		enc.wf(strconv.FormatInt(rv.Int(), 10))
+	case reflect.Uint, reflect.Uint8, reflect.Uint16,
+		reflect.Uint32, reflect.Uint64:
+		enc.wf(strconv.FormatUint(rv.Uint(), 10))
+	case reflect.Float32:
+		enc.wf(floatAddDecimal(strconv.FormatFloat(rv.Float(), 'f', -1, 32)))
+	case reflect.Float64:
+		enc.wf(floatAddDecimal(strconv.FormatFloat(rv.Float(), 'f', -1, 64)))
+	case reflect.Array, reflect.Slice:
+		enc.eArrayOrSliceElement(rv)
+	case reflect.Interface:
+		enc.eElement(rv.Elem())
+	case reflect.String:
+		enc.writeQuoted(rv.String())
+	default:
+		panic(e("Unexpected primitive type: %s", rv.Kind()))
+	}
+}
+
+// By the TOML spec, all floats must have a decimal with at least one
+// number on either side.
+func floatAddDecimal(fstr string) string {
+	if !strings.Contains(fstr, ".") {
+		return fstr + ".0"
+	}
+	return fstr
+}
+
+func (enc *Encoder) writeQuoted(s string) {
+	enc.wf("\"%s\"", quotedReplacer.Replace(s))
+}
+
+func (enc *Encoder) eArrayOrSliceElement(rv reflect.Value) {
+	length := rv.Len()
+	enc.wf("[")
+	for i := 0; i < length; i++ {
+		elem := rv.Index(i)
+		enc.eElement(elem)
+		if i != length-1 {
+			enc.wf(", ")
+		}
+	}
+	enc.wf("]")
+}
+
+func (enc *Encoder) eArrayOfTables(key Key, rv reflect.Value) {
+	if len(key) == 0 {
+		encPanic(errNoKey)
+	}
+	for i := 0; i < rv.Len(); i++ {
+		trv := rv.Index(i)
+		if isNil(trv) {
+			continue
+		}
+		panicIfInvalidKey(key)
+		enc.newline()
+		enc.wf("%s[[%s]]", enc.indentStr(key), key.maybeQuotedAll())
+		enc.newline()
+		enc.eMapOrStruct(key, trv)
+	}
+}
+
+func (enc *Encoder) eTable(key Key, rv reflect.Value) {
+	panicIfInvalidKey(key)
+	if len(key) == 1 {
+		// Output an extra new line between top-level tables.
+		// (The newline isn't written if nothing else has been written though.)
+		enc.newline()
+	}
+	if len(key) > 0 {
+		enc.wf("%s[%s]", enc.indentStr(key), key.maybeQuotedAll())
+		enc.newline()
+	}
+	enc.eMapOrStruct(key, rv)
+}
+
+func (enc *Encoder) eMapOrStruct(key Key, rv reflect.Value) {
+	switch rv := eindirect(rv); rv.Kind() {
+	case reflect.Map:
+		enc.eMap(key, rv)
+	case reflect.Struct:
+		enc.eStruct(key, rv)
+	default:
+		panic("eTable: unhandled reflect.Value Kind: " + rv.Kind().String())
+	}
+}
+
+func (enc *Encoder) eMap(key Key, rv reflect.Value) {
+	rt := rv.Type()
+	if rt.Key().Kind() != reflect.String {
+		encPanic(errNonString)
+	}
+
+	// Sort keys so that we have deterministic output. And write keys directly
+	// underneath this key first, before writing sub-structs or sub-maps.
+	var mapKeysDirect, mapKeysSub []string
+	for _, mapKey := range rv.MapKeys() {
+		k := mapKey.String()
+		if typeIsHash(tomlTypeOfGo(rv.MapIndex(mapKey))) {
+			mapKeysSub = append(mapKeysSub, k)
+		} else {
+			mapKeysDirect = append(mapKeysDirect, k)
+		}
+	}
+
+	var writeMapKeys = func(mapKeys []string) {
+		sort.Strings(mapKeys)
+		for _, mapKey := range mapKeys {
+			mrv := rv.MapIndex(reflect.ValueOf(mapKey))
+			if isNil(mrv) {
+				// Don't write anything for nil fields.
+				continue
+			}
+			enc.encode(key.add(mapKey), mrv)
+		}
+	}
+	writeMapKeys(mapKeysDirect)
+	writeMapKeys(mapKeysSub)
+}
+
+func (enc *Encoder) eStruct(key Key, rv reflect.Value) {
+	// Write keys for fields directly under this key first, because if we write
+	// a field that creates a new table, then all keys under it will be in that
+	// table (not the one we're writing here).
+	rt := rv.Type()
+	var fieldsDirect, fieldsSub [][]int
+	var addFields func(rt reflect.Type, rv reflect.Value, start []int)
+	addFields = func(rt reflect.Type, rv reflect.Value, start []int) {
+		for i := 0; i < rt.NumField(); i++ {
+			f := rt.Field(i)
+			// skip unexported fields
+			if f.PkgPath != "" && !f.Anonymous {
+				continue
+			}
+			frv := rv.Field(i)
+			if f.Anonymous {
+				t := f.Type
+				switch t.Kind() {
+				case reflect.Struct:
+					addFields(t, frv, f.Index)
+					continue
+				case reflect.Ptr:
+					if t.Elem().Kind() == reflect.Struct {
+						if !frv.IsNil() {
+							addFields(t.Elem(), frv.Elem(), f.Index)
+						}
+						continue
+					}
+					// Fall through to the normal field encoding logic below
+					// for non-struct anonymous fields.
+				}
+			}
+
+			if typeIsHash(tomlTypeOfGo(frv)) {
+				fieldsSub = append(fieldsSub, append(start, f.Index...))
+			} else {
+				fieldsDirect = append(fieldsDirect, append(start, f.Index...))
+			}
+		}
+	}
+	addFields(rt, rv, nil)
+
+	var writeFields = func(fields [][]int) {
+		for _, fieldIndex := range fields {
+			sft := rt.FieldByIndex(fieldIndex)
+			sf := rv.FieldByIndex(fieldIndex)
+			if isNil(sf) {
+				// Don't write anything for nil fields.
+				continue
+			}
+
+			tag := sft.Tag.Get("toml")
+			if tag == "-" {
+				continue
+			}
+			keyName, opts := getOptions(tag)
+			if keyName == "" {
+				keyName = sft.Name
+			}
+			if _, ok := opts["omitempty"]; ok && isEmpty(sf) {
+				continue
+			} else if _, ok := opts["omitzero"]; ok && isZero(sf) {
+				continue
+			}
+
+			enc.encode(key.add(keyName), sf)
+		}
+	}
+	writeFields(fieldsDirect)
+	writeFields(fieldsSub)
+}
+
+// tomlTypeName returns the TOML type name of the Go value's type. It is
+// used to determine whether the types of array elements are mixed (which is
+// forbidden). If the Go value is nil, then it is illegal for it to be an array
+// element, and valueIsNil is returned as true.
+
+// Returns the TOML type of a Go value. The type may be `nil`, which means
+// no concrete TOML type could be found.
+func tomlTypeOfGo(rv reflect.Value) tomlType {
+	if isNil(rv) || !rv.IsValid() {
+		return nil
+	}
+	switch rv.Kind() {
+	case reflect.Bool:
+		return tomlBool
+	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32,
+		reflect.Int64,
+		reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32,
+		reflect.Uint64:
+		return tomlInteger
+	case reflect.Float32, reflect.Float64:
+		return tomlFloat
+	case reflect.Array, reflect.Slice:
+		if typeEqual(tomlHash, tomlArrayType(rv)) {
+			return tomlArrayHash
+		} else {
+			return tomlArray
+		}
+	case reflect.Ptr, reflect.Interface:
+		return tomlTypeOfGo(rv.Elem())
+	case reflect.String:
+		return tomlString
+	case reflect.Map:
+		return tomlHash
+	case reflect.Struct:
+		switch rv.Interface().(type) {
+		case time.Time:
+			return tomlDatetime
+		case TextMarshaler:
+			return tomlString
+		default:
+			return tomlHash
+		}
+	default:
+		panic("unexpected reflect.Kind: " + rv.Kind().String())
+	}
+}
+
+// tomlArrayType returns the element type of a TOML array. The type returned
+// may be nil if it cannot be determined (e.g., a nil slice or a zero length
+// slize). This function may also panic if it finds a type that cannot be
+// expressed in TOML (such as nil elements, heterogeneous arrays or directly
+// nested arrays of tables).
+func tomlArrayType(rv reflect.Value) tomlType {
+	if isNil(rv) || !rv.IsValid() || rv.Len() == 0 {
+		return nil
+	}
+	firstType := tomlTypeOfGo(rv.Index(0))
+	if firstType == nil {
+		encPanic(errArrayNilElement)
+	}
+
+	rvlen := rv.Len()
+	for i := 1; i < rvlen; i++ {
+		elem := rv.Index(i)
+		switch elemType := tomlTypeOfGo(elem); {
+		case elemType == nil:
+			encPanic(errArrayNilElement)
+		case !typeEqual(firstType, elemType):
+			encPanic(errArrayMixedElementTypes)
+		}
+	}
+	// If we have a nested array, then we must make sure that the nested
+	// array contains ONLY primitives.
+	// This checks arbitrarily nested arrays.
+	if typeEqual(firstType, tomlArray) || typeEqual(firstType, tomlArrayHash) {
+		nest := tomlArrayType(eindirect(rv.Index(0)))
+		if typeEqual(nest, tomlHash) || typeEqual(nest, tomlArrayHash) {
+			encPanic(errArrayNoTable)
+		}
+	}
+	return firstType
+}
+
+func getOptions(keyName string) (string, map[string]struct{}) {
+	opts := make(map[string]struct{})
+	ss := strings.Split(keyName, ",")
+	name := ss[0]
+	if len(ss) > 1 {
+		for _, opt := range ss {
+			opts[opt] = struct{}{}
+		}
+	}
+
+	return name, opts
+}
+
+func isZero(rv reflect.Value) bool {
+	switch rv.Kind() {
+	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
+		return rv.Int() == 0
+	case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64:
+		return rv.Uint() == 0
+	case reflect.Float32, reflect.Float64:
+		return rv.Float() == 0.0
+	}
+	return false
+}
+
+func isEmpty(rv reflect.Value) bool {
+	switch rv.Kind() {
+	case reflect.Array, reflect.Slice, reflect.Map, reflect.String:
+		return rv.Len() == 0
+	case reflect.Bool:
+		return !rv.Bool()
+	}
+	return false
+}
+
+func (enc *Encoder) newline() {
+	if enc.hasWritten {
+		enc.wf("\n")
+	}
+}
+
+func (enc *Encoder) keyEqElement(key Key, val reflect.Value) {
+	if len(key) == 0 {
+		encPanic(errNoKey)
+	}
+	panicIfInvalidKey(key)
+	enc.wf("%s%s = ", enc.indentStr(key), key.maybeQuoted(len(key)-1))
+	enc.eElement(val)
+	enc.newline()
+}
+
+func (enc *Encoder) wf(format string, v ...interface{}) {
+	if _, err := fmt.Fprintf(enc.w, format, v...); err != nil {
+		encPanic(err)
+	}
+	enc.hasWritten = true
+}
+
+func (enc *Encoder) indentStr(key Key) string {
+	return strings.Repeat(enc.Indent, len(key)-1)
+}
+
+func encPanic(err error) {
+	panic(tomlEncodeError{err})
+}
+
+func eindirect(v reflect.Value) reflect.Value {
+	switch v.Kind() {
+	case reflect.Ptr, reflect.Interface:
+		return eindirect(v.Elem())
+	default:
+		return v
+	}
+}
+
+func isNil(rv reflect.Value) bool {
+	switch rv.Kind() {
+	case reflect.Interface, reflect.Map, reflect.Ptr, reflect.Slice:
+		return rv.IsNil()
+	default:
+		return false
+	}
+}
+
+func panicIfInvalidKey(key Key) {
+	for _, k := range key {
+		if len(k) == 0 {
+			encPanic(e("Key '%s' is not a valid table name. Key names "+
+				"cannot be empty.", key.maybeQuotedAll()))
+		}
+	}
+}
+
+func isValidKeyName(s string) bool {
+	return len(s) != 0
+}
diff --git a/vendor/github.com/BurntSushi/toml/encoding_types.go b/vendor/github.com/BurntSushi/toml/encoding_types.go
new file mode 100644
index 000000000..d36e1dd60
--- /dev/null
+++ b/vendor/github.com/BurntSushi/toml/encoding_types.go
@@ -0,0 +1,19 @@
+// +build go1.2
+
+package toml
+
+// In order to support Go 1.1, we define our own TextMarshaler and
+// TextUnmarshaler types. For Go 1.2+, we just alias them with the
+// standard library interfaces.
+
+import (
+	"encoding"
+)
+
+// TextMarshaler is a synonym for encoding.TextMarshaler. It is defined here
+// so that Go 1.1 can be supported.
+type TextMarshaler encoding.TextMarshaler
+
+// TextUnmarshaler is a synonym for encoding.TextUnmarshaler. It is defined
+// here so that Go 1.1 can be supported.
+type TextUnmarshaler encoding.TextUnmarshaler
diff --git a/vendor/github.com/BurntSushi/toml/encoding_types_1.1.go b/vendor/github.com/BurntSushi/toml/encoding_types_1.1.go
new file mode 100644
index 000000000..e8d503d04
--- /dev/null
+++ b/vendor/github.com/BurntSushi/toml/encoding_types_1.1.go
@@ -0,0 +1,18 @@
+// +build !go1.2
+
+package toml
+
+// These interfaces were introduced in Go 1.2, so we add them manually when
+// compiling for Go 1.1.
+
+// TextMarshaler is a synonym for encoding.TextMarshaler. It is defined here
+// so that Go 1.1 can be supported.
+type TextMarshaler interface {
+	MarshalText() (text []byte, err error)
+}
+
+// TextUnmarshaler is a synonym for encoding.TextUnmarshaler. It is defined
+// here so that Go 1.1 can be supported.
+type TextUnmarshaler interface {
+	UnmarshalText(text []byte) error
+}
diff --git a/vendor/github.com/BurntSushi/toml/lex.go b/vendor/github.com/BurntSushi/toml/lex.go
new file mode 100644
index 000000000..9b20b3a81
--- /dev/null
+++ b/vendor/github.com/BurntSushi/toml/lex.go
@@ -0,0 +1,871 @@
+package toml
+
+import (
+	"fmt"
+	"strings"
+	"unicode/utf8"
+)
+
+type itemType int
+
+const (
+	itemError itemType = iota
+	itemNIL            // used in the parser to indicate no type
+	itemEOF
+	itemText
+	itemString
+	itemRawString
+	itemMultilineString
+	itemRawMultilineString
+	itemBool
+	itemInteger
+	itemFloat
+	itemDatetime
+	itemArray // the start of an array
+	itemArrayEnd
+	itemTableStart
+	itemTableEnd
+	itemArrayTableStart
+	itemArrayTableEnd
+	itemKeyStart
+	itemCommentStart
+)
+
+const (
+	eof             = 0
+	tableStart      = '['
+	tableEnd        = ']'
+	arrayTableStart = '['
+	arrayTableEnd   = ']'
+	tableSep        = '.'
+	keySep          = '='
+	arrayStart      = '['
+	arrayEnd        = ']'
+	arrayValTerm    = ','
+	commentStart    = '#'
+	stringStart     = '"'
+	stringEnd       = '"'
+	rawStringStart  = '\''
+	rawStringEnd    = '\''
+)
+
+type stateFn func(lx *lexer) stateFn
+
+type lexer struct {
+	input string
+	start int
+	pos   int
+	width int
+	line  int
+	state stateFn
+	items chan item
+
+	// A stack of state functions used to maintain context.
+	// The idea is to reuse parts of the state machine in various places.
+	// For example, values can appear at the top level or within arbitrarily
+	// nested arrays. The last state on the stack is used after a value has
+	// been lexed. Similarly for comments.
+	stack []stateFn
+}
+
+type item struct {
+	typ  itemType
+	val  string
+	line int
+}
+
+func (lx *lexer) nextItem() item {
+	for {
+		select {
+		case item := <-lx.items:
+			return item
+		default:
+			lx.state = lx.state(lx)
+		}
+	}
+}
+
+func lex(input string) *lexer {
+	lx := &lexer{
+		input: input + "\n",
+		state: lexTop,
+		line:  1,
+		items: make(chan item, 10),
+		stack: make([]stateFn, 0, 10),
+	}
+	return lx
+}
+
+func (lx *lexer) push(state stateFn) {
+	lx.stack = append(lx.stack, state)
+}
+
+func (lx *lexer) pop() stateFn {
+	if len(lx.stack) == 0 {
+		return lx.errorf("BUG in lexer: no states to pop.")
+	}
+	last := lx.stack[len(lx.stack)-1]
+	lx.stack = lx.stack[0 : len(lx.stack)-1]
+	return last
+}
+
+func (lx *lexer) current() string {
+	return lx.input[lx.start:lx.pos]
+}
+
+func (lx *lexer) emit(typ itemType) {
+	lx.items <- item{typ, lx.current(), lx.line}
+	lx.start = lx.pos
+}
+
+func (lx *lexer) emitTrim(typ itemType) {
+	lx.items <- item{typ, strings.TrimSpace(lx.current()), lx.line}
+	lx.start = lx.pos
+}
+
+func (lx *lexer) next() (r rune) {
+	if lx.pos >= len(lx.input) {
+		lx.width = 0
+		return eof
+	}
+
+	if lx.input[lx.pos] == '\n' {
+		lx.line++
+	}
+	r, lx.width = utf8.DecodeRuneInString(lx.input[lx.pos:])
+	lx.pos += lx.width
+	return r
+}
+
+// ignore skips over the pending input before this point.
+func (lx *lexer) ignore() {
+	lx.start = lx.pos
+}
+
+// backup steps back one rune. Can be called only once per call of next.
+func (lx *lexer) backup() {
+	lx.pos -= lx.width
+	if lx.pos < len(lx.input) && lx.input[lx.pos] == '\n' {
+		lx.line--
+	}
+}
+
+// accept consumes the next rune if it's equal to `valid`.
+func (lx *lexer) accept(valid rune) bool {
+	if lx.next() == valid {
+		return true
+	}
+	lx.backup()
+	return false
+}
+
+// peek returns but does not consume the next rune in the input.
+func (lx *lexer) peek() rune {
+	r := lx.next()
+	lx.backup()
+	return r
+}
+
+// errorf stops all lexing by emitting an error and returning `nil`.
+// Note that any value that is a character is escaped if it's a special
+// character (new lines, tabs, etc.).
+func (lx *lexer) errorf(format string, values ...interface{}) stateFn {
+	lx.items <- item{
+		itemError,
+		fmt.Sprintf(format, values...),
+		lx.line,
+	}
+	return nil
+}
+
+// lexTop consumes elements at the top level of TOML data.
+func lexTop(lx *lexer) stateFn {
+	r := lx.next()
+	if isWhitespace(r) || isNL(r) {
+		return lexSkip(lx, lexTop)
+	}
+
+	switch r {
+	case commentStart:
+		lx.push(lexTop)
+		return lexCommentStart
+	case tableStart:
+		return lexTableStart
+	case eof:
+		if lx.pos > lx.start {
+			return lx.errorf("Unexpected EOF.")
+		}
+		lx.emit(itemEOF)
+		return nil
+	}
+
+	// At this point, the only valid item can be a key, so we back up
+	// and let the key lexer do the rest.
+	lx.backup()
+	lx.push(lexTopEnd)
+	return lexKeyStart
+}
+
+// lexTopEnd is entered whenever a top-level item has been consumed. (A value
+// or a table.) It must see only whitespace, and will turn back to lexTop
+// upon a new line. If it sees EOF, it will quit the lexer successfully.
+func lexTopEnd(lx *lexer) stateFn {
+	r := lx.next()
+	switch {
+	case r == commentStart:
+		// a comment will read to a new line for us.
+		lx.push(lexTop)
+		return lexCommentStart
+	case isWhitespace(r):
+		return lexTopEnd
+	case isNL(r):
+		lx.ignore()
+		return lexTop
+	case r == eof:
+		lx.ignore()
+		return lexTop
+	}
+	return lx.errorf("Expected a top-level item to end with a new line, "+
+		"comment or EOF, but got %q instead.", r)
+}
+
+// lexTable lexes the beginning of a table. Namely, it makes sure that
+// it starts with a character other than '.' and ']'.
+// It assumes that '[' has already been consumed.
+// It also handles the case that this is an item in an array of tables.
+// e.g., '[[name]]'.
+func lexTableStart(lx *lexer) stateFn {
+	if lx.peek() == arrayTableStart {
+		lx.next()
+		lx.emit(itemArrayTableStart)
+		lx.push(lexArrayTableEnd)
+	} else {
+		lx.emit(itemTableStart)
+		lx.push(lexTableEnd)
+	}
+	return lexTableNameStart
+}
+
+func lexTableEnd(lx *lexer) stateFn {
+	lx.emit(itemTableEnd)
+	return lexTopEnd
+}
+
+func lexArrayTableEnd(lx *lexer) stateFn {
+	if r := lx.next(); r != arrayTableEnd {
+		return lx.errorf("Expected end of table array name delimiter %q, "+
+			"but got %q instead.", arrayTableEnd, r)
+	}
+	lx.emit(itemArrayTableEnd)
+	return lexTopEnd
+}
+
+func lexTableNameStart(lx *lexer) stateFn {
+	switch r := lx.peek(); {
+	case r == tableEnd || r == eof:
+		return lx.errorf("Unexpected end of table name. (Table names cannot " +
+			"be empty.)")
+	case r == tableSep:
+		return lx.errorf("Unexpected table separator. (Table names cannot " +
+			"be empty.)")
+	case r == stringStart || r == rawStringStart:
+		lx.ignore()
+		lx.push(lexTableNameEnd)
+		return lexValue // reuse string lexing
+	default:
+		return lexBareTableName
+	}
+}
+
+// lexTableName lexes the name of a table. It assumes that at least one
+// valid character for the table has already been read.
+func lexBareTableName(lx *lexer) stateFn {
+	switch r := lx.next(); {
+	case isBareKeyChar(r):
+		return lexBareTableName
+	case r == tableSep || r == tableEnd:
+		lx.backup()
+		lx.emitTrim(itemText)
+		return lexTableNameEnd
+	default:
+		return lx.errorf("Bare keys cannot contain %q.", r)
+	}
+}
+
+// lexTableNameEnd reads the end of a piece of a table name, optionally
+// consuming whitespace.
+func lexTableNameEnd(lx *lexer) stateFn {
+	switch r := lx.next(); {
+	case isWhitespace(r):
+		return lexTableNameEnd
+	case r == tableSep:
+		lx.ignore()
+		return lexTableNameStart
+	case r == tableEnd:
+		return lx.pop()
+	default:
+		return lx.errorf("Expected '.' or ']' to end table name, but got %q "+
+			"instead.", r)
+	}
+}
+
+// lexKeyStart consumes a key name up until the first non-whitespace character.
+// lexKeyStart will ignore whitespace.
+func lexKeyStart(lx *lexer) stateFn {
+	r := lx.peek()
+	switch {
+	case r == keySep:
+		return lx.errorf("Unexpected key separator %q.", keySep)
+	case isWhitespace(r) || isNL(r):
+		lx.next()
+		return lexSkip(lx, lexKeyStart)
+	case r == stringStart || r == rawStringStart:
+		lx.ignore()
+		lx.emit(itemKeyStart)
+		lx.push(lexKeyEnd)
+		return lexValue // reuse string lexing
+	default:
+		lx.ignore()
+		lx.emit(itemKeyStart)
+		return lexBareKey
+	}
+}
+
+// lexBareKey consumes the text of a bare key. Assumes that the first character
+// (which is not whitespace) has not yet been consumed.
+func lexBareKey(lx *lexer) stateFn {
+	switch r := lx.next(); {
+	case isBareKeyChar(r):
+		return lexBareKey
+	case isWhitespace(r):
+		lx.emitTrim(itemText)
+		return lexKeyEnd
+	case r == keySep:
+		lx.backup()
+		lx.emitTrim(itemText)
+		return lexKeyEnd
+	default:
+		return lx.errorf("Bare keys cannot contain %q.", r)
+	}
+}
+
+// lexKeyEnd consumes the end of a key and trims whitespace (up to the key
+// separator).
+func lexKeyEnd(lx *lexer) stateFn {
+	switch r := lx.next(); {
+	case r == keySep:
+		return lexSkip(lx, lexValue)
+	case isWhitespace(r):
+		return lexSkip(lx, lexKeyEnd)
+	default:
+		return lx.errorf("Expected key separator %q, but got %q instead.",
+			keySep, r)
+	}
+}
+
+// lexValue starts the consumption of a value anywhere a value is expected.
+// lexValue will ignore whitespace.
+// After a value is lexed, the last state on the next is popped and returned.
+func lexValue(lx *lexer) stateFn {
+	// We allow whitespace to precede a value, but NOT new lines.
+	// In array syntax, the array states are responsible for ignoring new
+	// lines.
+	r := lx.next()
+	if isWhitespace(r) {
+		return lexSkip(lx, lexValue)
+	}
+
+	switch {
+	case r == arrayStart:
+		lx.ignore()
+		lx.emit(itemArray)
+		return lexArrayValue
+	case r == stringStart:
+		if lx.accept(stringStart) {
+			if lx.accept(stringStart) {
+				lx.ignore() // Ignore """
+				return lexMultilineString
+			}
+			lx.backup()
+		}
+		lx.ignore() // ignore the '"'
+		return lexString
+	case r == rawStringStart:
+		if lx.accept(rawStringStart) {
+			if lx.accept(rawStringStart) {
+				lx.ignore() // Ignore """
+				return lexMultilineRawString
+			}
+			lx.backup()
+		}
+		lx.ignore() // ignore the "'"
+		return lexRawString
+	case r == 't':
+		return lexTrue
+	case r == 'f':
+		return lexFalse
+	case r == '-':
+		return lexNumberStart
+	case isDigit(r):
+		lx.backup() // avoid an extra state and use the same as above
+		return lexNumberOrDateStart
+	case r == '.': // special error case, be kind to users
+		return lx.errorf("Floats must start with a digit, not '.'.")
+	}
+	return lx.errorf("Expected value but found %q instead.", r)
+}
+
+// lexArrayValue consumes one value in an array. It assumes that '[' or ','
+// have already been consumed. All whitespace and new lines are ignored.
+func lexArrayValue(lx *lexer) stateFn {
+	r := lx.next()
+	switch {
+	case isWhitespace(r) || isNL(r):
+		return lexSkip(lx, lexArrayValue)
+	case r == commentStart:
+		lx.push(lexArrayValue)
+		return lexCommentStart
+	case r == arrayValTerm:
+		return lx.errorf("Unexpected array value terminator %q.",
+			arrayValTerm)
+	case r == arrayEnd:
+		return lexArrayEnd
+	}
+
+	lx.backup()
+	lx.push(lexArrayValueEnd)
+	return lexValue
+}
+
+// lexArrayValueEnd consumes the cruft between values of an array. Namely,
+// it ignores whitespace and expects either a ',' or a ']'.
+func lexArrayValueEnd(lx *lexer) stateFn {
+	r := lx.next()
+	switch {
+	case isWhitespace(r) || isNL(r):
+		return lexSkip(lx, lexArrayValueEnd)
+	case r == commentStart:
+		lx.push(lexArrayValueEnd)
+		return lexCommentStart
+	case r == arrayValTerm:
+		lx.ignore()
+		return lexArrayValue // move on to the next value
+	case r == arrayEnd:
+		return lexArrayEnd
+	}
+	return lx.errorf("Expected an array value terminator %q or an array "+
+		"terminator %q, but got %q instead.", arrayValTerm, arrayEnd, r)
+}
+
+// lexArrayEnd finishes the lexing of an array. It assumes that a ']' has
+// just been consumed.
+func lexArrayEnd(lx *lexer) stateFn {
+	lx.ignore()
+	lx.emit(itemArrayEnd)
+	return lx.pop()
+}
+
+// lexString consumes the inner contents of a string. It assumes that the
+// beginning '"' has already been consumed and ignored.
+func lexString(lx *lexer) stateFn {
+	r := lx.next()
+	switch {
+	case isNL(r):
+		return lx.errorf("Strings cannot contain new lines.")
+	case r == '\\':
+		lx.push(lexString)
+		return lexStringEscape
+	case r == stringEnd:
+		lx.backup()
+		lx.emit(itemString)
+		lx.next()
+		lx.ignore()
+		return lx.pop()
+	}
+	return lexString
+}
+
+// lexMultilineString consumes the inner contents of a string. It assumes that
+// the beginning '"""' has already been consumed and ignored.
+func lexMultilineString(lx *lexer) stateFn {
+	r := lx.next()
+	switch {
+	case r == '\\':
+		return lexMultilineStringEscape
+	case r == stringEnd:
+		if lx.accept(stringEnd) {
+			if lx.accept(stringEnd) {
+				lx.backup()
+				lx.backup()
+				lx.backup()
+				lx.emit(itemMultilineString)
+				lx.next()
+				lx.next()
+				lx.next()
+				lx.ignore()
+				return lx.pop()
+			}
+			lx.backup()
+		}
+	}
+	return lexMultilineString
+}
+
+// lexRawString consumes a raw string. Nothing can be escaped in such a string.
+// It assumes that the beginning "'" has already been consumed and ignored.
+func lexRawString(lx *lexer) stateFn {
+	r := lx.next()
+	switch {
+	case isNL(r):
+		return lx.errorf("Strings cannot contain new lines.")
+	case r == rawStringEnd:
+		lx.backup()
+		lx.emit(itemRawString)
+		lx.next()
+		lx.ignore()
+		return lx.pop()
+	}
+	return lexRawString
+}
+
+// lexMultilineRawString consumes a raw string. Nothing can be escaped in such
+// a string. It assumes that the beginning "'" has already been consumed and
+// ignored.
+func lexMultilineRawString(lx *lexer) stateFn {
+	r := lx.next()
+	switch {
+	case r == rawStringEnd:
+		if lx.accept(rawStringEnd) {
+			if lx.accept(rawStringEnd) {
+				lx.backup()
+				lx.backup()
+				lx.backup()
+				lx.emit(itemRawMultilineString)
+				lx.next()
+				lx.next()
+				lx.next()
+				lx.ignore()
+				return lx.pop()
+			}
+			lx.backup()
+		}
+	}
+	return lexMultilineRawString
+}
+
+// lexMultilineStringEscape consumes an escaped character. It assumes that the
+// preceding '\\' has already been consumed.
+func lexMultilineStringEscape(lx *lexer) stateFn {
+	// Handle the special case first:
+	if isNL(lx.next()) {
+		return lexMultilineString
+	} else {
+		lx.backup()
+		lx.push(lexMultilineString)
+		return lexStringEscape(lx)
+	}
+}
+
+func lexStringEscape(lx *lexer) stateFn {
+	r := lx.next()
+	switch r {
+	case 'b':
+		fallthrough
+	case 't':
+		fallthrough
+	case 'n':
+		fallthrough
+	case 'f':
+		fallthrough
+	case 'r':
+		fallthrough
+	case '"':
+		fallthrough
+	case '\\':
+		return lx.pop()
+	case 'u':
+		return lexShortUnicodeEscape
+	case 'U':
+		return lexLongUnicodeEscape
+	}
+	return lx.errorf("Invalid escape character %q. Only the following "+
+		"escape characters are allowed: "+
+		"\\b, \\t, \\n, \\f, \\r, \\\", \\/, \\\\, "+
+		"\\uXXXX and \\UXXXXXXXX.", r)
+}
+
+func lexShortUnicodeEscape(lx *lexer) stateFn {
+	var r rune
+	for i := 0; i < 4; i++ {
+		r = lx.next()
+		if !isHexadecimal(r) {
+			return lx.errorf("Expected four hexadecimal digits after '\\u', "+
+				"but got '%s' instead.", lx.current())
+		}
+	}
+	return lx.pop()
+}
+
+func lexLongUnicodeEscape(lx *lexer) stateFn {
+	var r rune
+	for i := 0; i < 8; i++ {
+		r = lx.next()
+		if !isHexadecimal(r) {
+			return lx.errorf("Expected eight hexadecimal digits after '\\U', "+
+				"but got '%s' instead.", lx.current())
+		}
+	}
+	return lx.pop()
+}
+
+// lexNumberOrDateStart consumes either a (positive) integer, float or
+// datetime. It assumes that NO negative sign has been consumed.
+func lexNumberOrDateStart(lx *lexer) stateFn {
+	r := lx.next()
+	if !isDigit(r) {
+		if r == '.' {
+			return lx.errorf("Floats must start with a digit, not '.'.")
+		} else {
+			return lx.errorf("Expected a digit but got %q.", r)
+		}
+	}
+	return lexNumberOrDate
+}
+
+// lexNumberOrDate consumes either a (positive) integer, float or datetime.
+func lexNumberOrDate(lx *lexer) stateFn {
+	r := lx.next()
+	switch {
+	case r == '-':
+		if lx.pos-lx.start != 5 {
+			return lx.errorf("All ISO8601 dates must be in full Zulu form.")
+		}
+		return lexDateAfterYear
+	case isDigit(r):
+		return lexNumberOrDate
+	case r == '.':
+		return lexFloatStart
+	}
+
+	lx.backup()
+	lx.emit(itemInteger)
+	return lx.pop()
+}
+
+// lexDateAfterYear consumes a full Zulu Datetime in ISO8601 format.
+// It assumes that "YYYY-" has already been consumed.
+func lexDateAfterYear(lx *lexer) stateFn {
+	formats := []rune{
+		// digits are '0'.
+		// everything else is direct equality.
+		'0', '0', '-', '0', '0',
+		'T',
+		'0', '0', ':', '0', '0', ':', '0', '0',
+		'Z',
+	}
+	for _, f := range formats {
+		r := lx.next()
+		if f == '0' {
+			if !isDigit(r) {
+				return lx.errorf("Expected digit in ISO8601 datetime, "+
+					"but found %q instead.", r)
+			}
+		} else if f != r {
+			return lx.errorf("Expected %q in ISO8601 datetime, "+
+				"but found %q instead.", f, r)
+		}
+	}
+	lx.emit(itemDatetime)
+	return lx.pop()
+}
+
+// lexNumberStart consumes either an integer or a float. It assumes that
+// a negative sign has already been read, but that *no* digits have been
+// consumed. lexNumberStart will move to the appropriate integer or float
+// states.
+func lexNumberStart(lx *lexer) stateFn {
+	// we MUST see a digit. Even floats have to start with a digit.
+	r := lx.next()
+	if !isDigit(r) {
+		if r == '.' {
+			return lx.errorf("Floats must start with a digit, not '.'.")
+		} else {
+			return lx.errorf("Expected a digit but got %q.", r)
+		}
+	}
+	return lexNumber
+}
+
+// lexNumber consumes an integer or a float after seeing the first digit.
+func lexNumber(lx *lexer) stateFn {
+	r := lx.next()
+	switch {
+	case isDigit(r):
+		return lexNumber
+	case r == '.':
+		return lexFloatStart
+	}
+
+	lx.backup()
+	lx.emit(itemInteger)
+	return lx.pop()
+}
+
+// lexFloatStart starts the consumption of digits of a float after a '.'.
+// Namely, at least one digit is required.
+func lexFloatStart(lx *lexer) stateFn {
+	r := lx.next()
+	if !isDigit(r) {
+		return lx.errorf("Floats must have a digit after the '.', but got "+
+			"%q instead.", r)
+	}
+	return lexFloat
+}
+
+// lexFloat consumes the digits of a float after a '.'.
+// Assumes that one digit has been consumed after a '.' already.
+func lexFloat(lx *lexer) stateFn {
+	r := lx.next()
+	if isDigit(r) {
+		return lexFloat
+	}
+
+	lx.backup()
+	lx.emit(itemFloat)
+	return lx.pop()
+}
+
+// lexConst consumes the s[1:] in s. It assumes that s[0] has already been
+// consumed.
+func lexConst(lx *lexer, s string) stateFn {
+	for i := range s[1:] {
+		if r := lx.next(); r != rune(s[i+1]) {
+			return lx.errorf("Expected %q, but found %q instead.", s[:i+1],
+				s[:i]+string(r))
+		}
+	}
+	return nil
+}
+
+// lexTrue consumes the "rue" in "true". It assumes that 't' has already
+// been consumed.
+func lexTrue(lx *lexer) stateFn {
+	if fn := lexConst(lx, "true"); fn != nil {
+		return fn
+	}
+	lx.emit(itemBool)
+	return lx.pop()
+}
+
+// lexFalse consumes the "alse" in "false". It assumes that 'f' has already
+// been consumed.
+func lexFalse(lx *lexer) stateFn {
+	if fn := lexConst(lx, "false"); fn != nil {
+		return fn
+	}
+	lx.emit(itemBool)
+	return lx.pop()
+}
+
+// lexCommentStart begins the lexing of a comment. It will emit
+// itemCommentStart and consume no characters, passing control to lexComment.
+func lexCommentStart(lx *lexer) stateFn {
+	lx.ignore()
+	lx.emit(itemCommentStart)
+	return lexComment
+}
+
+// lexComment lexes an entire comment. It assumes that '#' has been consumed.
+// It will consume *up to* the first new line character, and pass control
+// back to the last state on the stack.
+func lexComment(lx *lexer) stateFn {
+	r := lx.peek()
+	if isNL(r) || r == eof {
+		lx.emit(itemText)
+		return lx.pop()
+	}
+	lx.next()
+	return lexComment
+}
+
+// lexSkip ignores all slurped input and moves on to the next state.
+func lexSkip(lx *lexer, nextState stateFn) stateFn {
+	return func(lx *lexer) stateFn {
+		lx.ignore()
+		return nextState
+	}
+}
+
+// isWhitespace returns true if `r` is a whitespace character according
+// to the spec.
+func isWhitespace(r rune) bool {
+	return r == '\t' || r == ' '
+}
+
+func isNL(r rune) bool {
+	return r == '\n' || r == '\r'
+}
+
+func isDigit(r rune) bool {
+	return r >= '0' && r <= '9'
+}
+
+func isHexadecimal(r rune) bool {
+	return (r >= '0' && r <= '9') ||
+		(r >= 'a' && r <= 'f') ||
+		(r >= 'A' && r <= 'F')
+}
+
+func isBareKeyChar(r rune) bool {
+	return (r >= 'A' && r <= 'Z') ||
+		(r >= 'a' && r <= 'z') ||
+		(r >= '0' && r <= '9') ||
+		r == '_' ||
+		r == '-'
+}
+
+func (itype itemType) String() string {
+	switch itype {
+	case itemError:
+		return "Error"
+	case itemNIL:
+		return "NIL"
+	case itemEOF:
+		return "EOF"
+	case itemText:
+		return "Text"
+	case itemString:
+		return "String"
+	case itemRawString:
+		return "String"
+	case itemMultilineString:
+		return "String"
+	case itemRawMultilineString:
+		return "String"
+	case itemBool:
+		return "Bool"
+	case itemInteger:
+		return "Integer"
+	case itemFloat:
+		return "Float"
+	case itemDatetime:
+		return "DateTime"
+	case itemTableStart:
+		return "TableStart"
+	case itemTableEnd:
+		return "TableEnd"
+	case itemKeyStart:
+		return "KeyStart"
+	case itemArray:
+		return "Array"
+	case itemArrayEnd:
+		return "ArrayEnd"
+	case itemCommentStart:
+		return "CommentStart"
+	}
+	panic(fmt.Sprintf("BUG: Unknown type '%d'.", int(itype)))
+}
+
+func (item item) String() string {
+	return fmt.Sprintf("(%s, %s)", item.typ.String(), item.val)
+}
diff --git a/vendor/github.com/BurntSushi/toml/parse.go b/vendor/github.com/BurntSushi/toml/parse.go
new file mode 100644
index 000000000..6a82e84f6
--- /dev/null
+++ b/vendor/github.com/BurntSushi/toml/parse.go
@@ -0,0 +1,493 @@
+package toml
+
+import (
+	"fmt"
+	"log"
+	"strconv"
+	"strings"
+	"time"
+	"unicode"
+	"unicode/utf8"
+)
+
+type parser struct {
+	mapping map[string]interface{}
+	types   map[string]tomlType
+	lx      *lexer
+
+	// A list of keys in the order that they appear in the TOML data.
+	ordered []Key
+
+	// the full key for the current hash in scope
+	context Key
+
+	// the base key name for everything except hashes
+	currentKey string
+
+	// rough approximation of line number
+	approxLine int
+
+	// A map of 'key.group.names' to whether they were created implicitly.
+	implicits map[string]bool
+}
+
+type parseError string
+
+func (pe parseError) Error() string {
+	return string(pe)
+}
+
+func parse(data string) (p *parser, err error) {
+	defer func() {
+		if r := recover(); r != nil {
+			var ok bool
+			if err, ok = r.(parseError); ok {
+				return
+			}
+			panic(r)
+		}
+	}()
+
+	p = &parser{
+		mapping:   make(map[string]interface{}),
+		types:     make(map[string]tomlType),
+		lx:        lex(data),
+		ordered:   make([]Key, 0),
+		implicits: make(map[string]bool),
+	}
+	for {
+		item := p.next()
+		if item.typ == itemEOF {
+			break
+		}
+		p.topLevel(item)
+	}
+
+	return p, nil
+}
+
+func (p *parser) panicf(format string, v ...interface{}) {
+	msg := fmt.Sprintf("Near line %d (last key parsed '%s'): %s",
+		p.approxLine, p.current(), fmt.Sprintf(format, v...))
+	panic(parseError(msg))
+}
+
+func (p *parser) next() item {
+	it := p.lx.nextItem()
+	if it.typ == itemError {
+		p.panicf("%s", it.val)
+	}
+	return it
+}
+
+func (p *parser) bug(format string, v ...interface{}) {
+	log.Panicf("BUG: %s\n\n", fmt.Sprintf(format, v...))
+}
+
+func (p *parser) expect(typ itemType) item {
+	it := p.next()
+	p.assertEqual(typ, it.typ)
+	return it
+}
+
+func (p *parser) assertEqual(expected, got itemType) {
+	if expected != got {
+		p.bug("Expected '%s' but got '%s'.", expected, got)
+	}
+}
+
+func (p *parser) topLevel(item item) {
+	switch item.typ {
+	case itemCommentStart:
+		p.approxLine = item.line
+		p.expect(itemText)
+	case itemTableStart:
+		kg := p.next()
+		p.approxLine = kg.line
+
+		var key Key
+		for ; kg.typ != itemTableEnd && kg.typ != itemEOF; kg = p.next() {
+			key = append(key, p.keyString(kg))
+		}
+		p.assertEqual(itemTableEnd, kg.typ)
+
+		p.establishContext(key, false)
+		p.setType("", tomlHash)
+		p.ordered = append(p.ordered, key)
+	case itemArrayTableStart:
+		kg := p.next()
+		p.approxLine = kg.line
+
+		var key Key
+		for ; kg.typ != itemArrayTableEnd && kg.typ != itemEOF; kg = p.next() {
+			key = append(key, p.keyString(kg))
+		}
+		p.assertEqual(itemArrayTableEnd, kg.typ)
+
+		p.establishContext(key, true)
+		p.setType("", tomlArrayHash)
+		p.ordered = append(p.ordered, key)
+	case itemKeyStart:
+		kname := p.next()
+		p.approxLine = kname.line
+		p.currentKey = p.keyString(kname)
+
+		val, typ := p.value(p.next())
+		p.setValue(p.currentKey, val)
+		p.setType(p.currentKey, typ)
+		p.ordered = append(p.ordered, p.context.add(p.currentKey))
+		p.currentKey = ""
+	default:
+		p.bug("Unexpected type at top level: %s", item.typ)
+	}
+}
+
+// Gets a string for a key (or part of a key in a table name).
+func (p *parser) keyString(it item) string {
+	switch it.typ {
+	case itemText:
+		return it.val
+	case itemString, itemMultilineString,
+		itemRawString, itemRawMultilineString:
+		s, _ := p.value(it)
+		return s.(string)
+	default:
+		p.bug("Unexpected key type: %s", it.typ)
+		panic("unreachable")
+	}
+}
+
+// value translates an expected value from the lexer into a Go value wrapped
+// as an empty interface.
+func (p *parser) value(it item) (interface{}, tomlType) {
+	switch it.typ {
+	case itemString:
+		return p.replaceEscapes(it.val), p.typeOfPrimitive(it)
+	case itemMultilineString:
+		trimmed := stripFirstNewline(stripEscapedWhitespace(it.val))
+		return p.replaceEscapes(trimmed), p.typeOfPrimitive(it)
+	case itemRawString:
+		return it.val, p.typeOfPrimitive(it)
+	case itemRawMultilineString:
+		return stripFirstNewline(it.val), p.typeOfPrimitive(it)
+	case itemBool:
+		switch it.val {
+		case "true":
+			return true, p.typeOfPrimitive(it)
+		case "false":
+			return false, p.typeOfPrimitive(it)
+		}
+		p.bug("Expected boolean value, but got '%s'.", it.val)
+	case itemInteger:
+		num, err := strconv.ParseInt(it.val, 10, 64)
+		if err != nil {
+			// See comment below for floats describing why we make a
+			// distinction between a bug and a user error.
+			if e, ok := err.(*strconv.NumError); ok &&
+				e.Err == strconv.ErrRange {
+
+				p.panicf("Integer '%s' is out of the range of 64-bit "+
+					"signed integers.", it.val)
+			} else {
+				p.bug("Expected integer value, but got '%s'.", it.val)
+			}
+		}
+		return num, p.typeOfPrimitive(it)
+	case itemFloat:
+		num, err := strconv.ParseFloat(it.val, 64)
+		if err != nil {
+			// Distinguish float values. Normally, it'd be a bug if the lexer
+			// provides an invalid float, but it's possible that the float is
+			// out of range of valid values (which the lexer cannot determine).
+			// So mark the former as a bug but the latter as a legitimate user
+			// error.
+			//
+			// This is also true for integers.
+			if e, ok := err.(*strconv.NumError); ok &&
+				e.Err == strconv.ErrRange {
+
+				p.panicf("Float '%s' is out of the range of 64-bit "+
+					"IEEE-754 floating-point numbers.", it.val)
+			} else {
+				p.bug("Expected float value, but got '%s'.", it.val)
+			}
+		}
+		return num, p.typeOfPrimitive(it)
+	case itemDatetime:
+		t, err := time.Parse("2006-01-02T15:04:05Z", it.val)
+		if err != nil {
+			p.panicf("Invalid RFC3339 Zulu DateTime: '%s'.", it.val)
+		}
+		return t, p.typeOfPrimitive(it)
+	case itemArray:
+		array := make([]interface{}, 0)
+		types := make([]tomlType, 0)
+
+		for it = p.next(); it.typ != itemArrayEnd; it = p.next() {
+			if it.typ == itemCommentStart {
+				p.expect(itemText)
+				continue
+			}
+
+			val, typ := p.value(it)
+			array = append(array, val)
+			types = append(types, typ)
+		}
+		return array, p.typeOfArray(types)
+	}
+	p.bug("Unexpected value type: %s", it.typ)
+	panic("unreachable")
+}
+
+// establishContext sets the current context of the parser,
+// where the context is either a hash or an array of hashes. Which one is
+// set depends on the value of the `array` parameter.
+//
+// Establishing the context also makes sure that the key isn't a duplicate, and
+// will create implicit hashes automatically.
+func (p *parser) establishContext(key Key, array bool) {
+	var ok bool
+
+	// Always start at the top level and drill down for our context.
+	hashContext := p.mapping
+	keyContext := make(Key, 0)
+
+	// We only need implicit hashes for key[0:-1]
+	for _, k := range key[0 : len(key)-1] {
+		_, ok = hashContext[k]
+		keyContext = append(keyContext, k)
+
+		// No key? Make an implicit hash and move on.
+		if !ok {
+			p.addImplicit(keyContext)
+			hashContext[k] = make(map[string]interface{})
+		}
+
+		// If the hash context is actually an array of tables, then set
+		// the hash context to the last element in that array.
+		//
+		// Otherwise, it better be a table, since this MUST be a key group (by
+		// virtue of it not being the last element in a key).
+		switch t := hashContext[k].(type) {
+		case []map[string]interface{}:
+			hashContext = t[len(t)-1]
+		case map[string]interface{}:
+			hashContext = t
+		default:
+			p.panicf("Key '%s' was already created as a hash.", keyContext)
+		}
+	}
+
+	p.context = keyContext
+	if array {
+		// If this is the first element for this array, then allocate a new
+		// list of tables for it.
+		k := key[len(key)-1]
+		if _, ok := hashContext[k]; !ok {
+			hashContext[k] = make([]map[string]interface{}, 0, 5)
+		}
+
+		// Add a new table. But make sure the key hasn't already been used
+		// for something else.
+		if hash, ok := hashContext[k].([]map[string]interface{}); ok {
+			hashContext[k] = append(hash, make(map[string]interface{}))
+		} else {
+			p.panicf("Key '%s' was already created and cannot be used as "+
+				"an array.", keyContext)
+		}
+	} else {
+		p.setValue(key[len(key)-1], make(map[string]interface{}))
+	}
+	p.context = append(p.context, key[len(key)-1])
+}
+
+// setValue sets the given key to the given value in the current context.
+// It will make sure that the key hasn't already been defined, account for
+// implicit key groups.
+func (p *parser) setValue(key string, value interface{}) {
+	var tmpHash interface{}
+	var ok bool
+
+	hash := p.mapping
+	keyContext := make(Key, 0)
+	for _, k := range p.context {
+		keyContext = append(keyContext, k)
+		if tmpHash, ok = hash[k]; !ok {
+			p.bug("Context for key '%s' has not been established.", keyContext)
+		}
+		switch t := tmpHash.(type) {
+		case []map[string]interface{}:
+			// The context is a table of hashes. Pick the most recent table
+			// defined as the current hash.
+			hash = t[len(t)-1]
+		case map[string]interface{}:
+			hash = t
+		default:
+			p.bug("Expected hash to have type 'map[string]interface{}', but "+
+				"it has '%T' instead.", tmpHash)
+		}
+	}
+	keyContext = append(keyContext, key)
+
+	if _, ok := hash[key]; ok {
+		// Typically, if the given key has already been set, then we have
+		// to raise an error since duplicate keys are disallowed. However,
+		// it's possible that a key was previously defined implicitly. In this
+		// case, it is allowed to be redefined concretely. (See the
+		// `tests/valid/implicit-and-explicit-after.toml` test in `toml-test`.)
+		//
+		// But we have to make sure to stop marking it as an implicit. (So that
+		// another redefinition provokes an error.)
+		//
+		// Note that since it has already been defined (as a hash), we don't
+		// want to overwrite it. So our business is done.
+		if p.isImplicit(keyContext) {
+			p.removeImplicit(keyContext)
+			return
+		}
+
+		// Otherwise, we have a concrete key trying to override a previous
+		// key, which is *always* wrong.
+		p.panicf("Key '%s' has already been defined.", keyContext)
+	}
+	hash[key] = value
+}
+
+// setType sets the type of a particular value at a given key.
+// It should be called immediately AFTER setValue.
+//
+// Note that if `key` is empty, then the type given will be applied to the
+// current context (which is either a table or an array of tables).
+func (p *parser) setType(key string, typ tomlType) {
+	keyContext := make(Key, 0, len(p.context)+1)
+	for _, k := range p.context {
+		keyContext = append(keyContext, k)
+	}
+	if len(key) > 0 { // allow type setting for hashes
+		keyContext = append(keyContext, key)
+	}
+	p.types[keyContext.String()] = typ
+}
+
+// addImplicit sets the given Key as having been created implicitly.
+func (p *parser) addImplicit(key Key) {
+	p.implicits[key.String()] = true
+}
+
+// removeImplicit stops tagging the given key as having been implicitly
+// created.
+func (p *parser) removeImplicit(key Key) {
+	p.implicits[key.String()] = false
+}
+
+// isImplicit returns true if the key group pointed to by the key was created
+// implicitly.
+func (p *parser) isImplicit(key Key) bool {
+	return p.implicits[key.String()]
+}
+
+// current returns the full key name of the current context.
+func (p *parser) current() string {
+	if len(p.currentKey) == 0 {
+		return p.context.String()
+	}
+	if len(p.context) == 0 {
+		return p.currentKey
+	}
+	return fmt.Sprintf("%s.%s", p.context, p.currentKey)
+}
+
+func stripFirstNewline(s string) string {
+	if len(s) == 0 || s[0] != '\n' {
+		return s
+	}
+	return s[1:]
+}
+
+func stripEscapedWhitespace(s string) string {
+	esc := strings.Split(s, "\\\n")
+	if len(esc) > 1 {
+		for i := 1; i < len(esc); i++ {
+			esc[i] = strings.TrimLeftFunc(esc[i], unicode.IsSpace)
+		}
+	}
+	return strings.Join(esc, "")
+}
+
+func (p *parser) replaceEscapes(str string) string {
+	var replaced []rune
+	s := []byte(str)
+	r := 0
+	for r < len(s) {
+		if s[r] != '\\' {
+			c, size := utf8.DecodeRune(s[r:])
+			r += size
+			replaced = append(replaced, c)
+			continue
+		}
+		r += 1
+		if r >= len(s) {
+			p.bug("Escape sequence at end of string.")
+			return ""
+		}
+		switch s[r] {
+		default:
+			p.bug("Expected valid escape code after \\, but got %q.", s[r])
+			return ""
+		case 'b':
+			replaced = append(replaced, rune(0x0008))
+			r += 1
+		case 't':
+			replaced = append(replaced, rune(0x0009))
+			r += 1
+		case 'n':
+			replaced = append(replaced, rune(0x000A))
+			r += 1
+		case 'f':
+			replaced = append(replaced, rune(0x000C))
+			r += 1
+		case 'r':
+			replaced = append(replaced, rune(0x000D))
+			r += 1
+		case '"':
+			replaced = append(replaced, rune(0x0022))
+			r += 1
+		case '\\':
+			replaced = append(replaced, rune(0x005C))
+			r += 1
+		case 'u':
+			// At this point, we know we have a Unicode escape of the form
+			// `uXXXX` at [r, r+5). (Because the lexer guarantees this
+			// for us.)
+			escaped := p.asciiEscapeToUnicode(s[r+1 : r+5])
+			replaced = append(replaced, escaped)
+			r += 5
+		case 'U':
+			// At this point, we know we have a Unicode escape of the form
+			// `uXXXX` at [r, r+9). (Because the lexer guarantees this
+			// for us.)
+			escaped := p.asciiEscapeToUnicode(s[r+1 : r+9])
+			replaced = append(replaced, escaped)
+			r += 9
+		}
+	}
+	return string(replaced)
+}
+
+func (p *parser) asciiEscapeToUnicode(bs []byte) rune {
+	s := string(bs)
+	hex, err := strconv.ParseUint(strings.ToLower(s), 16, 32)
+	if err != nil {
+		p.bug("Could not parse '%s' as a hexadecimal number, but the "+
+			"lexer claims it's OK: %s", s, err)
+	}
+	if !utf8.ValidRune(rune(hex)) {
+		p.panicf("Escaped character '\\u%s' is not valid UTF-8.", s)
+	}
+	return rune(hex)
+}
+
+func isStringType(ty itemType) bool {
+	return ty == itemString || ty == itemMultilineString ||
+		ty == itemRawString || ty == itemRawMultilineString
+}
diff --git a/vendor/github.com/BurntSushi/toml/type_check.go b/vendor/github.com/BurntSushi/toml/type_check.go
new file mode 100644
index 000000000..c73f8afc1
--- /dev/null
+++ b/vendor/github.com/BurntSushi/toml/type_check.go
@@ -0,0 +1,91 @@
+package toml
+
+// tomlType represents any Go type that corresponds to a TOML type.
+// While the first draft of the TOML spec has a simplistic type system that
+// probably doesn't need this level of sophistication, we seem to be militating
+// toward adding real composite types.
+type tomlType interface {
+	typeString() string
+}
+
+// typeEqual accepts any two types and returns true if they are equal.
+func typeEqual(t1, t2 tomlType) bool {
+	if t1 == nil || t2 == nil {
+		return false
+	}
+	return t1.typeString() == t2.typeString()
+}
+
+func typeIsHash(t tomlType) bool {
+	return typeEqual(t, tomlHash) || typeEqual(t, tomlArrayHash)
+}
+
+type tomlBaseType string
+
+func (btype tomlBaseType) typeString() string {
+	return string(btype)
+}
+
+func (btype tomlBaseType) String() string {
+	return btype.typeString()
+}
+
+var (
+	tomlInteger   tomlBaseType = "Integer"
+	tomlFloat     tomlBaseType = "Float"
+	tomlDatetime  tomlBaseType = "Datetime"
+	tomlString    tomlBaseType = "String"
+	tomlBool      tomlBaseType = "Bool"
+	tomlArray     tomlBaseType = "Array"
+	tomlHash      tomlBaseType = "Hash"
+	tomlArrayHash tomlBaseType = "ArrayHash"
+)
+
+// typeOfPrimitive returns a tomlType of any primitive value in TOML.
+// Primitive values are: Integer, Float, Datetime, String and Bool.
+//
+// Passing a lexer item other than the following will cause a BUG message
+// to occur: itemString, itemBool, itemInteger, itemFloat, itemDatetime.
+func (p *parser) typeOfPrimitive(lexItem item) tomlType {
+	switch lexItem.typ {
+	case itemInteger:
+		return tomlInteger
+	case itemFloat:
+		return tomlFloat
+	case itemDatetime:
+		return tomlDatetime
+	case itemString:
+		return tomlString
+	case itemMultilineString:
+		return tomlString
+	case itemRawString:
+		return tomlString
+	case itemRawMultilineString:
+		return tomlString
+	case itemBool:
+		return tomlBool
+	}
+	p.bug("Cannot infer primitive type of lex item '%s'.", lexItem)
+	panic("unreachable")
+}
+
+// typeOfArray returns a tomlType for an array given a list of types of its
+// values.
+//
+// In the current spec, if an array is homogeneous, then its type is always
+// "Array". If the array is not homogeneous, an error is generated.
+func (p *parser) typeOfArray(types []tomlType) tomlType {
+	// Empty arrays are cool.
+	if len(types) == 0 {
+		return tomlArray
+	}
+
+	theType := types[0]
+	for _, t := range types[1:] {
+		if !typeEqual(theType, t) {
+			p.panicf("Array contains values of type '%s' and '%s', but "+
+				"arrays must be homogeneous.", theType, t)
+		}
+	}
+	return tomlArray
+}
diff --git a/vendor/github.com/BurntSushi/toml/type_fields.go b/vendor/github.com/BurntSushi/toml/type_fields.go
new file mode 100644
index 000000000..6da608af4
--- /dev/null
+++ b/vendor/github.com/BurntSushi/toml/type_fields.go
@@ -0,0 +1,241 @@
+package toml
+
+// Struct field handling is adapted from code in encoding/json:
+//
+// Copyright 2010 The Go Authors.  All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the Go distribution.
+
+import (
+	"reflect"
+	"sort"
+	"sync"
+)
+
+// A field represents a single field found in a struct.
+type field struct {
+	name  string       // the name of the field (`toml` tag included)
+	tag   bool         // whether field has a `toml` tag
+	index []int        // represents the depth of an anonymous field
+	typ   reflect.Type // the type of the field
+}
+
+// byName sorts field by name, breaking ties with depth,
+// then breaking ties with "name came from toml tag", then
+// breaking ties with index sequence.
+type byName []field
+
+func (x byName) Len() int { return len(x) }
+
+func (x byName) Swap(i, j int) { x[i], x[j] = x[j], x[i] }
+
+func (x byName) Less(i, j int) bool {
+	if x[i].name != x[j].name {
+		return x[i].name < x[j].name
+	}
+	if len(x[i].index) != len(x[j].index) {
+		return len(x[i].index) < len(x[j].index)
+	}
+	if x[i].tag != x[j].tag {
+		return x[i].tag
+	}
+	return byIndex(x).Less(i, j)
+}
+
+// byIndex sorts field by index sequence.
+type byIndex []field
+
+func (x byIndex) Len() int { return len(x) }
+
+func (x byIndex) Swap(i, j int) { x[i], x[j] = x[j], x[i] }
+
+func (x byIndex) Less(i, j int) bool {
+	for k, xik := range x[i].index {
+		if k >= len(x[j].index) {
+			return false
+		}
+		if xik != x[j].index[k] {
+			return xik < x[j].index[k]
+		}
+	}
+	return len(x[i].index) < len(x[j].index)
+}
+
+// typeFields returns a list of fields that TOML should recognize for the given
+// type. The algorithm is breadth-first search over the set of structs to
+// include - the top struct and then any reachable anonymous structs.
+func typeFields(t reflect.Type) []field {
+	// Anonymous fields to explore at the current level and the next.
+	current := []field{}
+	next := []field{{typ: t}}
+
+	// Count of queued names for current level and the next.
+	count := map[reflect.Type]int{}
+	nextCount := map[reflect.Type]int{}
+
+	// Types already visited at an earlier level.
+	visited := map[reflect.Type]bool{}
+
+	// Fields found.
+	var fields []field
+
+	for len(next) > 0 {
+		current, next = next, current[:0]
+		count, nextCount = nextCount, map[reflect.Type]int{}
+
+		for _, f := range current {
+			if visited[f.typ] {
+				continue
+			}
+			visited[f.typ] = true
+
+			// Scan f.typ for fields to include.
+			for i := 0; i < f.typ.NumField(); i++ {
+				sf := f.typ.Field(i)
+				if sf.PkgPath != "" && !sf.Anonymous { // unexported
+					continue
+				}
+				name, _ := getOptions(sf.Tag.Get("toml"))
+				if name == "-" {
+					continue
+				}
+				index := make([]int, len(f.index)+1)
+				copy(index, f.index)
+				index[len(f.index)] = i
+
+				ft := sf.Type
+				if ft.Name() == "" && ft.Kind() == reflect.Ptr {
+					// Follow pointer.
+					ft = ft.Elem()
+				}
+
+				// Record found field and index sequence.
+				if name != "" || !sf.Anonymous || ft.Kind() != reflect.Struct {
+					tagged := name != ""
+					if name == "" {
+						name = sf.Name
+					}
+					fields = append(fields, field{name, tagged, index, ft})
+					if count[f.typ] > 1 {
+						// If there were multiple instances, add a second,
+						// so that the annihilation code will see a duplicate.
+						// It only cares about the distinction between 1 or 2,
+						// so don't bother generating any more copies.
+						fields = append(fields, fields[len(fields)-1])
+					}
+					continue
+				}
+
+				// Record new anonymous struct to explore in next round.
+				nextCount[ft]++
+				if nextCount[ft] == 1 {
+					f := field{name: ft.Name(), index: index, typ: ft}
+					next = append(next, f)
+				}
+			}
+		}
+	}
+
+	sort.Sort(byName(fields))
+
+	// Delete all fields that are hidden by the Go rules for embedded fields,
+	// except that fields with TOML tags are promoted.
+
+	// The fields are sorted in primary order of name, secondary order
+	// of field index length. Loop over names; for each name, delete
+	// hidden fields by choosing the one dominant field that survives.
+	out := fields[:0]
+	for advance, i := 0, 0; i < len(fields); i += advance {
+		// One iteration per name.
+		// Find the sequence of fields with the name of this first field.
+		fi := fields[i]
+		name := fi.name
+		for advance = 1; i+advance < len(fields); advance++ {
+			fj := fields[i+advance]
+			if fj.name != name {
+				break
+			}
+		}
+		if advance == 1 { // Only one field with this name
+			out = append(out, fi)
+			continue
+		}
+		dominant, ok := dominantField(fields[i : i+advance])
+		if ok {
+			out = append(out, dominant)
+		}
+	}
+
+	fields = out
+	sort.Sort(byIndex(fields))
+
+	return fields
+}
+
+// dominantField looks through the fields, all of which are known to
+// have the same name, to find the single field that dominates the
+// others using Go's embedding rules, modified by the presence of
+// TOML tags. If there are multiple top-level fields, the boolean
+// will be false: This condition is an error in Go and we skip all
+// the fields.
+func dominantField(fields []field) (field, bool) {
+	// The fields are sorted in increasing index-length order. The winner
+	// must therefore be one with the shortest index length. Drop all
+	// longer entries, which is easy: just truncate the slice.
+	length := len(fields[0].index)
+	tagged := -1 // Index of first tagged field.
+	for i, f := range fields {
+		if len(f.index) > length {
+			fields = fields[:i]
+			break
+		}
+		if f.tag {
+			if tagged >= 0 {
+				// Multiple tagged fields at the same level: conflict.
+				// Return no field.
+				return field{}, false
+			}
+			tagged = i
+		}
+	}
+	if tagged >= 0 {
+		return fields[tagged], true
+	}
+	// All remaining fields have the same length. If there's more than one,
+	// we have a conflict (two fields named "X" at the same level) and we
+	// return no field.
+	if len(fields) > 1 {
+		return field{}, false
+	}
+	return fields[0], true
+}
+
+var fieldCache struct {
+	sync.RWMutex
+	m map[reflect.Type][]field
+}
+
+// cachedTypeFields is like typeFields but uses a cache to avoid repeated work.
+func cachedTypeFields(t reflect.Type) []field {
+	fieldCache.RLock()
+	f := fieldCache.m[t]
+	fieldCache.RUnlock()
+	if f != nil {
+		return f
+	}
+
+	// Compute fields without lock.
+	// Might duplicate effort but won't hold other computations back.
+	f = typeFields(t)
+	if f == nil {
+		f = []field{}
+	}
+
+	fieldCache.Lock()
+	if fieldCache.m == nil {
+		fieldCache.m = map[reflect.Type][]field{}
+	}
+	fieldCache.m[t] = f
+	fieldCache.Unlock()
+	return f
+}