bump(github.com/BurntSushi/toml): 2fffd0e6ca4b88558be4bcab497231c95270cd07

third_party/github.com/BurntSushi/toml/README.md

@@ -1,6 +1,10 @@
-# TOML parser for Go with reflection
+# TOML parser and encoder for Go with reflection
 
-TOML stands for Tom's Obvious, Minimal Language.
+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
 
@@ -26,7 +30,8 @@ tomlv some-toml-file.toml
 ## Testing
 
 This package passes all tests in
-[toml-test](https://github.com/BurntSushi/toml-test).
+[toml-test](https://github.com/BurntSushi/toml-test) for both the decoder
+and the encoder.
 
 ## Examples
 
@@ -78,6 +83,56 @@ type TOML struct {
 }
 ```
 
+## 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 := 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:

third_party/github.com/BurntSushi/toml/decode.go

@@ -1,6 +1,7 @@
 package toml
 
 import (
+	"encoding"
 	"fmt"
 	"io"
 	"io/ioutil"
@@ -43,11 +44,62 @@ func PrimitiveDecode(primValue Primitive, v interface{}) error {
 // 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. Here's an
+// example for parsing durations:
+//
+//	type duration struct {
+//		time.Duration
+//	}
+//
+//	func (d *duration) UnmarshalText(text []byte) error {
+//		var err error
+//		d.Duration, err = time.ParseDuration(string(text))
+//		return err
+//	}
+//
+//	func ExampleUnmarshaler() {
+//		blob := `
+//	[[song]]
+//	name = "Thunder Road"
+//	duration = "4m49s"
+//
+//	[[song]]
+//	name = "Stairway to Heaven"
+//	duration = "8m03s"
+//	`
+//		type song struct {
+//			Name     string
+//			Duration duration
+//		}
+//		type songs struct {
+//			Song []song
+//		}
+//		var favorites songs
+//		if _, err := Decode(blob, &favorites); err != nil {
+//			log.Fatal(err)
+//		}
+//
+//		for _, s := range favorites.Song {
+//			fmt.Printf("%s (%s)\n", s.Name, s.Duration)
+//		}
+//		// Output:
+//		// Thunder Road (4m49s)
+//		// Stairway to Heaven (8m3s)
+//	}
+//
+// 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.)
@@ -100,11 +152,17 @@ func unify(data interface{}, rv reflect.Value) error {
 		return unifyAnything(data, rv)
 	}
 
-	// Special case. Go's `time.Time` is a struct, which we don't want
-	// to confuse with a user struct.
-	if rv.Type().AssignableTo(rvalue(time.Time{}).Type()) {
-		return unifyDatetime(data, rv)
+	// Special case. Look for a value satisfying the TextUnmarshaler interface.
+	if v, ok := rv.Interface().(encoding.TextUnmarshaler); ok {
+		return 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()
 
@@ -177,7 +235,7 @@ func unifyStruct(mapping interface{}, rv reflect.Value) error {
 			}
 			sf := indirect(subv)
 
-			if sf.CanSet() {
+			if isUnifiable(sf) {
 				if err := unify(datum, sf); err != nil {
 					return e("Type mismatch for '%s.%s': %s",
 						rv.Type().String(), f.name, err)
@@ -299,7 +357,7 @@ func unifyBool(data interface{}, rv reflect.Value) error {
 		rv.SetBool(b)
 		return nil
 	}
-	return badtype("integer", data)
+	return badtype("boolean", data)
 }
 
 func unifyAnything(data interface{}, rv reflect.Value) error {
@@ -308,6 +366,34 @@ func unifyAnything(data interface{}, rv reflect.Value) error {
 	return nil
 }
 
+func unifyText(data interface{}, v encoding.TextUnmarshaler) error {
+	var s string
+	switch sdata := data.(type) {
+	case encoding.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))
@@ -316,8 +402,17 @@ func rvalue(v interface{}) reflect.Value {
 // 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().(encoding.TextUnmarshaler); ok {
+				return pv
+			}
+		}
 		return v
 	}
 	if v.IsNil() {
@@ -326,6 +421,16 @@ func indirect(v reflect.Value) reflect.Value {
 	return indirect(reflect.Indirect(v))
 }
 
+func isUnifiable(rv reflect.Value) bool {
+	if rv.CanSet() {
+		return true
+	}
+	if _, ok := rv.Interface().(encoding.TextUnmarshaler); ok {
+		return true
+	}
+	return false
+}
+
 func tstring(rv reflect.Value) string {
 	return rv.Type().String()
 }
@@ -356,8 +461,6 @@ func insensitiveGet(
 // 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.
-//
-// (XXX: If TOML gets NULL values, that information will be added here too.)
 type MetaData struct {
 	mapping map[string]interface{}
 	types   map[string]tomlType

third_party/github.com/BurntSushi/toml/decode_test.go

@@ -379,9 +379,50 @@ ip = "10.0.0.2"
 		fmt.Printf("Ports: %v\n", s.Config.Ports)
 	}
 
-	// // Output:
+	// Output:
 	// Server: alpha (ip: 10.0.0.1) in Toronto created on 1987-07-05
 	// Ports: [8001 8002]
 	// Server: beta (ip: 10.0.0.2) in New Jersey created on 1887-01-05
 	// Ports: [9001 9002]
 }
+
+type duration struct {
+	time.Duration
+}
+
+func (d *duration) UnmarshalText(text []byte) error {
+	var err error
+	d.Duration, err = time.ParseDuration(string(text))
+	return err
+}
+
+// Example Unmarshaler blah blah.
+func ExampleUnmarshaler() {
+	blob := `
+[[song]]
+name = "Thunder Road"
+duration = "4m49s"
+
+[[song]]
+name = "Stairway to Heaven"
+duration = "8m03s"
+`
+	type song struct {
+		Name     string
+		Duration duration
+	}
+	type songs struct {
+		Song []song
+	}
+	var favorites songs
+	if _, err := Decode(blob, &favorites); err != nil {
+		log.Fatal(err)
+	}
+
+	for _, s := range favorites.Song {
+		fmt.Printf("%s (%s)\n", s.Name, s.Duration)
+	}
+	// Output:
+	// Thunder Road (4m49s)
+	// Stairway to Heaven (8m3s)
+}

third_party/github.com/BurntSushi/toml/encode.go

@@ -15,27 +15,41 @@ package toml
 
 import (
 	"bufio"
+	"encoding"
+	"errors"
 	"fmt"
 	"io"
 	"reflect"
+	"sort"
+	"strconv"
 	"strings"
 )
 
-type encoder struct {
+var (
+	ErrArrayMixedElementTypes = errors.New(
+		"can't encode array with mixed element types")
+	ErrArrayNilElement = errors.New(
+		"can't encode array with nil element")
+)
+
+type Encoder struct {
 	// A single indentation level. By default it is two spaces.
 	Indent string
 
 	w *bufio.Writer
+
+	// hasWritten is whether we have written any output to w yet.
+	hasWritten bool
 }
 
-func newEncoder(w io.Writer) *encoder {
-	return &encoder{
+func NewEncoder(w io.Writer) *Encoder {
+	return &Encoder{
 		w:      bufio.NewWriter(w),
 		Indent: "  ",
 	}
 }
 
-func (enc *encoder) Encode(v interface{}) error {
+func (enc *Encoder) Encode(v interface{}) error {
 	rv := eindirect(reflect.ValueOf(v))
 	if err := enc.encode(Key([]string{}), rv); err != nil {
 		return err
@@ -43,49 +57,466 @@ func (enc *encoder) Encode(v interface{}) error {
 	return enc.w.Flush()
 }
 
-func (enc *encoder) encode(key Key, rv reflect.Value) error {
+func (enc *Encoder) encode(key Key, rv reflect.Value) error {
+	// Special case. If we can marshal the type to text, then we used that.
+	if _, ok := rv.Interface().(encoding.TextMarshaler); ok {
+		err := enc.eKeyEq(key)
+		if err != nil {
+			return err
+		}
+		return enc.eElement(rv)
+	}
+
 	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:
+		err := enc.eKeyEq(key)
+		if err != nil {
+			return err
+		}
+		return enc.eElement(rv)
+	case reflect.Array, reflect.Slice:
+		return enc.eArrayOrSlice(key, rv)
+	case reflect.Interface:
+		if rv.IsNil() {
+			return nil
+		}
+		return enc.encode(key, rv.Elem())
+	case reflect.Map:
+		if rv.IsNil() {
+			return nil
+		}
+		return enc.eTable(key, rv)
+	case reflect.Ptr:
+		if rv.IsNil() {
+			return nil
+		}
+		return enc.encode(key, rv.Elem())
 	case reflect.Struct:
-		return enc.eStruct(key, rv)
-	case reflect.String:
-		return enc.eString(key, rv)
+		return enc.eTable(key, rv)
 	}
 	return e("Unsupported type for key '%s': %s", key, k)
 }
 
-func (enc *encoder) eStruct(key Key, rv reflect.Value) error {
-	rt := rv.Type()
-	for i := 0; i < rt.NumField(); i++ {
-		sft := rt.Field(i)
-		sf := rv.Field(i)
-		if err := enc.encode(key.add(sft.Name), sf); err != nil {
+// eElement encodes any value that can be an array element (primitives and
+// arrays).
+func (enc *Encoder) eElement(rv reflect.Value) error {
+	ws := func(s string) error {
+		_, err := io.WriteString(enc.w, s)
+		return err
+	}
+	// By the TOML spec, all floats must have a decimal with at least one
+	// number on either side.
+	floatAddDecimal := func(fstr string) string {
+		if !strings.Contains(fstr, ".") {
+			return fstr + ".0"
+		}
+		return fstr
+	}
+
+	// Special case. Use text marshaler if it's available for this value.
+	if v, ok := rv.Interface().(encoding.TextMarshaler); ok {
+		s, err := v.MarshalText()
+		if err != nil {
+			return err
+		}
+		return ws(string(s))
+	}
+
+	var err error
+	k := rv.Kind()
+	switch k {
+	case reflect.Bool:
+		err = ws(strconv.FormatBool(rv.Bool()))
+	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
+		err = ws(strconv.FormatInt(rv.Int(), 10))
+	case reflect.Uint, reflect.Uint8, reflect.Uint16,
+		reflect.Uint32, reflect.Uint64:
+		err = ws(strconv.FormatUint(rv.Uint(), 10))
+	case reflect.Float32:
+		err = ws(floatAddDecimal(strconv.FormatFloat(rv.Float(), 'f', -1, 32)))
+	case reflect.Float64:
+		err = ws(floatAddDecimal(strconv.FormatFloat(rv.Float(), 'f', -1, 64)))
+	case reflect.Array, reflect.Slice:
+		return enc.eArrayOrSliceElement(rv)
+	case reflect.Interface:
+		return enc.eElement(rv.Elem())
+	case reflect.String:
+		s := rv.String()
+		s = strings.NewReplacer(
+			"\t", "\\t",
+			"\n", "\\n",
+			"\r", "\\r",
+			"\"", "\\\"",
+			"\\", "\\\\",
+		).Replace(s)
+		err = ws("\"" + s + "\"")
+	default:
+		return e("Unexpected primitive type: %s", k)
+	}
+	return err
+}
+
+func (enc *Encoder) eArrayOrSlice(key Key, rv reflect.Value) error {
+	// Determine whether this is an array of tables or of primitives.
+	elemV := reflect.ValueOf(nil)
+	if rv.Len() > 0 {
+		elemV = rv.Index(0)
+	}
+	isTableType, err := isTOMLTableType(rv.Type().Elem(), elemV)
+	if err != nil {
+		return err
+	}
+
+	if len(key) > 0 && isTableType {
+		return enc.eArrayOfTables(key, rv)
+	}
+
+	err = enc.eKeyEq(key)
+	if err != nil {
+		return err
+	}
+	return enc.eArrayOrSliceElement(rv)
+}
+
+func (enc *Encoder) eArrayOrSliceElement(rv reflect.Value) error {
+	if _, err := enc.w.Write([]byte{'['}); err != nil {
+		return err
+	}
+
+	length := rv.Len()
+	if length > 0 {
+		arrayElemType, isNil := tomlTypeName(rv.Index(0))
+		if isNil {
+			return ErrArrayNilElement
+		}
+
+		for i := 0; i < length; i++ {
+			elem := rv.Index(i)
+
+			// Ensure that the array's elements each have the same TOML type.
+			elemType, isNil := tomlTypeName(elem)
+			if isNil {
+				return ErrArrayNilElement
+			}
+			if elemType != arrayElemType {
+				return ErrArrayMixedElementTypes
+			}
+
+			if err := enc.eElement(elem); err != nil {
+				return err
+			}
+			if i != length-1 {
+				if _, err := enc.w.Write([]byte(", ")); err != nil {
+					return err
+				}
+			}
+		}
+	}
+
+	if _, err := enc.w.Write([]byte{']'}); err != nil {
+		return err
+	}
+	return nil
+}
+
+func (enc *Encoder) eArrayOfTables(key Key, rv reflect.Value) error {
+	if enc.hasWritten {
+		_, err := enc.w.Write([]byte{'\n'})
+		if err != nil {
 			return err
 		}
 	}
+
+	for i := 0; i < rv.Len(); i++ {
+		trv := rv.Index(i)
+		if isNil(trv) {
+			continue
+		}
+
+		_, err := fmt.Fprintf(enc.w, "%s[[%s]]\n",
+			strings.Repeat(enc.Indent, len(key)-1), key.String())
+		if err != nil {
+			return err
+		}
+
+		err = enc.eMapOrStruct(key, trv)
+		if err != nil {
+			return err
+		}
+
+		if i != rv.Len()-1 {
+			if _, err := enc.w.Write([]byte("\n\n")); err != nil {
+				return err
+			}
+		}
+		enc.hasWritten = true
+	}
 	return nil
 }
 
-func (enc *encoder) eString(key Key, rv reflect.Value) error {
-	s := rv.String()
-	s = strings.NewReplacer(
-		"\t", "\\t",
-		"\n", "\\n",
-		"\r", "\\r",
-		"\"", "\\\"",
-		"\\", "\\\\",
-	).Replace(s)
-	s = "\"" + s + "\""
-	if err := enc.eKeyVal(key, s); err != nil {
+func isStructOrMap(rv reflect.Value) bool {
+	switch rv.Kind() {
+	case reflect.Interface, reflect.Ptr:
+		return isStructOrMap(rv.Elem())
+	case reflect.Map, reflect.Struct:
+		return true
+	default:
+		return false
+	}
+}
+
+func (enc *Encoder) eTable(key Key, rv reflect.Value) error {
+	if enc.hasWritten {
+		_, err := enc.w.Write([]byte{'\n'})
+		if err != nil {
+			return err
+		}
+	}
+	if len(key) > 0 {
+		_, err := fmt.Fprintf(enc.w, "%s[%s]\n",
+			strings.Repeat(enc.Indent, len(key)-1), key.String())
+		if err != nil {
+			return err
+		}
+	}
+	return enc.eMapOrStruct(key, rv)
+}
+
+func (enc *Encoder) eMapOrStruct(key Key, rv reflect.Value) error {
+	switch rv.Kind() {
+	case reflect.Map:
+		return enc.eMap(key, rv)
+	case reflect.Struct:
+		return enc.eStruct(key, rv)
+	case reflect.Ptr, reflect.Interface:
+		return enc.eMapOrStruct(key, rv.Elem())
+	default:
+		panic("eTable: unhandled reflect.Value Kind: " + rv.Kind().String())
+	}
+}
+
+func (enc *Encoder) eMap(key Key, rv reflect.Value) error {
+	rt := rv.Type()
+	if rt.Key().Kind() != reflect.String {
+		return errors.New("can't encode a map with non-string key type")
+	}
+
+	// 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()
+		mrv := rv.MapIndex(mapKey)
+		if isStructOrMap(mrv) {
+			mapKeysSub = append(mapKeysSub, k)
+		} else {
+			mapKeysDirect = append(mapKeysDirect, k)
+		}
+	}
+
+	var writeMapKeys = func(mapKeys []string) error {
+		sort.Strings(mapKeys)
+		for i, mapKey := range mapKeys {
+			mrv := rv.MapIndex(reflect.ValueOf(mapKey))
+			if isNil(mrv) {
+				// Don't write anything for nil fields.
+				continue
+			}
+			if err := enc.encode(key.add(mapKey), mrv); err != nil {
+				return err
+			}
+
+			if i != len(mapKeys)-1 {
+				if _, err := enc.w.Write([]byte{'\n'}); err != nil {
+					return err
+				}
+			}
+			enc.hasWritten = true
+		}
+
+		return nil
+	}
+
+	err := writeMapKeys(mapKeysDirect)
+	if err != nil {
+		return err
+	}
+	err = writeMapKeys(mapKeysSub)
+	if err != nil {
 		return err
 	}
 	return nil
 }
 
-func (enc *encoder) eKeyVal(key Key, value string) error {
-	out := fmt.Sprintf("%s%s = %s",
-		strings.Repeat(enc.Indent, len(key)-1), key[len(key)-1], value)
-	if _, err := fmt.Fprintln(enc.w, out); err != nil {
+func (enc *Encoder) eStruct(key Key, rv reflect.Value) error {
+	// 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)
+			frv := rv.Field(i)
+			if f.Anonymous {
+				t := frv.Type()
+				if t.Kind() == reflect.Ptr {
+					t = t.Elem()
+					frv = frv.Elem()
+				}
+				addFields(t, frv, f.Index)
+			} else if isStructOrMap(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) error {
+		for i, fieldIndex := range fields {
+			sft := rt.FieldByIndex(fieldIndex)
+			sf := rv.FieldByIndex(fieldIndex)
+			if isNil(sf) {
+				// Don't write anything for nil fields.
+				continue
+			}
+
+			keyName := sft.Tag.Get("toml")
+			if keyName == "-" {
+				continue
+			}
+			if keyName == "" {
+				keyName = sft.Name
+			}
+
+			if err := enc.encode(key.add(keyName), sf); err != nil {
+				return err
+			}
+
+			if i != len(fields)-1 {
+				if _, err := enc.w.Write([]byte{'\n'}); err != nil {
+					return err
+				}
+			}
+			enc.hasWritten = true
+		}
+		return nil
+	}
+
+	err := writeFields(fieldsDirect)
+	if err != nil {
+		return err
+	}
+	if len(fieldsDirect) > 0 && len(fieldsSub) > 0 {
+		_, err = enc.w.Write([]byte{'\n'})
+		if err != nil {
+			return err
+		}
+	}
+	err = writeFields(fieldsSub)
+	if err != nil {
+		return err
+	}
+	return nil
+}
+
+// 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.
+func tomlTypeName(rv reflect.Value) (typeName string, valueIsNil bool) {
+	if isNil(rv) {
+		return "", true
+	}
+	k := rv.Kind()
+	switch k {
+	case reflect.Bool:
+		return "bool", false
+	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64,
+		reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32,
+		reflect.Uint64:
+		return "integer", false
+	case reflect.Float32, reflect.Float64:
+		return "float", false
+	case reflect.Array, reflect.Slice:
+		return "array", false
+	case reflect.Ptr, reflect.Interface:
+		return tomlTypeName(rv.Elem())
+	case reflect.String:
+		return "string", false
+	case reflect.Map, reflect.Struct:
+		return "table", false
+	default:
+		panic("unexpected reflect.Kind: " + k.String())
+	}
+}
+
+// isTOMLTableType returns whether this type and value represents a TOML table
+// type (true) or element type (false). Both rt and rv are needed to determine
+// this, in case the Go type is interface{} or in case rv is nil. If there is
+// some other impossible situation detected, an error is returned.
+func isTOMLTableType(rt reflect.Type, rv reflect.Value) (bool, error) {
+	k := rt.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:
+		return false, nil
+	case reflect.Array, reflect.Slice:
+		// Make sure that these eventually contain an underlying non-table type
+		// element.
+		elemV := reflect.ValueOf(nil)
+		if rv.Len() > 0 {
+			elemV = rv.Index(0)
+		}
+		hasUnderlyingTableType, err := isTOMLTableType(rt.Elem(), elemV)
+		if err != nil {
+			return false, err
+		}
+		if hasUnderlyingTableType {
+			return true, errors.New("TOML array element can't contain a table")
+		}
+		return false, nil
+	case reflect.Ptr:
+		return isTOMLTableType(rt.Elem(), rv.Elem())
+	case reflect.Interface:
+		if rv.Kind() == reflect.Interface {
+			return false, nil
+		}
+		return isTOMLTableType(rv.Type(), rv)
+	case reflect.Map, reflect.Struct:
+		return true, nil
+	default:
+		panic("unexpected reflect.Kind: " + k.String())
+	}
+}
+
+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 (enc *Encoder) eKeyEq(key Key) error {
+	_, err := io.WriteString(enc.w, strings.Repeat(enc.Indent, len(key)-1))
+	if err != nil {
+		return err
+	}
+	_, err = io.WriteString(enc.w, key[len(key)-1]+" = ")
+	if err != nil {
 		return err
 	}
 	return nil

third_party/github.com/BurntSushi/toml/encode_test.go

@@ -5,21 +5,278 @@ import (
 	"testing"
 )
 
-type encodeSimple struct {
-	Location string
-	// Ages []int
-	// DOB time.Time
-}
-
+// XXX(burntsushi)
+// I think these tests probably should be removed. They are good, but they
+// ought to be obsolete by toml-test.
 func TestEncode(t *testing.T) {
-	v := encodeSimple{
-		Location: "Westborough, MA",
+	tests := map[string]struct {
+		input      interface{}
+		wantOutput string
+		wantError  error
+	}{
+		"bool field": {
+			input: struct {
+				BoolTrue  bool
+				BoolFalse bool
+			}{true, false},
+			wantOutput: "BoolTrue = true\nBoolFalse = false",
+		},
+		"int fields": {
+			input: struct {
+				Int   int
+				Int8  int8
+				Int16 int16
+				Int32 int32
+				Int64 int64
+			}{1, 2, 3, 4, 5},
+			wantOutput: "Int = 1\nInt8 = 2\nInt16 = 3\nInt32 = 4\nInt64 = 5",
+		},
+		"uint fields": {
+			input: struct {
+				Uint   uint
+				Uint8  uint8
+				Uint16 uint16
+				Uint32 uint32
+				Uint64 uint64
+			}{1, 2, 3, 4, 5},
+			wantOutput: "Uint = 1\nUint8 = 2\nUint16 = 3\nUint32 = 4" +
+				"\nUint64 = 5",
+		},
+		"float fields": {
+			input: struct {
+				Float32 float32
+				Float64 float64
+			}{1.5, 2.5},
+			wantOutput: "Float32 = 1.5\nFloat64 = 2.5",
+		},
+		"string field": {
+			input:      struct{ String string }{"foo"},
+			wantOutput: `String = "foo"`,
+		},
+		"array fields": {
+			input: struct {
+				IntArray0 [0]int
+				IntArray3 [3]int
+			}{[0]int{}, [3]int{1, 2, 3}},
+			wantOutput: "IntArray0 = []\nIntArray3 = [1, 2, 3]",
+		},
+		"slice fields": {
+			input: struct{ IntSliceNil, IntSlice0, IntSlice3 []int }{
+				nil, []int{}, []int{1, 2, 3},
+			},
+			wantOutput: "IntSlice0 = []\nIntSlice3 = [1, 2, 3]",
+		},
+		"nested arrays and slices": {
+			input: struct {
+				SliceOfArrays         [][2]int
+				ArrayOfSlices         [2][]int
+				SliceOfArraysOfSlices [][2][]int
+				ArrayOfSlicesOfArrays [2][][2]int
+				SliceOfMixedArrays    [][2]interface{}
+				ArrayOfMixedSlices    [2][]interface{}
+			}{
+				[][2]int{[2]int{1, 2}, [2]int{3, 4}},
+				[2][]int{[]int{1, 2}, []int{3, 4}},
+				[][2][]int{
+					[2][]int{
+						[]int{1, 2}, []int{3, 4},
+					},
+					[2][]int{
+						[]int{5, 6}, []int{7, 8},
+					},
+				},
+				[2][][2]int{
+					[][2]int{
+						[2]int{1, 2}, [2]int{3, 4},
+					},
+					[][2]int{
+						[2]int{5, 6}, [2]int{7, 8},
+					},
+				},
+				[][2]interface{}{
+					[2]interface{}{1, 2}, [2]interface{}{"a", "b"},
+				},
+				[2][]interface{}{
+					[]interface{}{1, 2}, []interface{}{"a", "b"},
+				},
+			},
+			wantOutput: `SliceOfArrays = [[1, 2], [3, 4]]
+ArrayOfSlices = [[1, 2], [3, 4]]
+SliceOfArraysOfSlices = [[[1, 2], [3, 4]], [[5, 6], [7, 8]]]
+ArrayOfSlicesOfArrays = [[[1, 2], [3, 4]], [[5, 6], [7, 8]]]
+SliceOfMixedArrays = [[1, 2], ["a", "b"]]
+ArrayOfMixedSlices = [[1, 2], ["a", "b"]]`,
+		},
+		"(error) slice with element type mismatch (string and integer)": {
+			input:     struct{ Mixed []interface{} }{[]interface{}{1, "a"}},
+			wantError: ErrArrayMixedElementTypes,
+		},
+		"(error) slice with element type mismatch (integer and float)": {
+			input:     struct{ Mixed []interface{} }{[]interface{}{1, 2.5}},
+			wantError: ErrArrayMixedElementTypes,
+		},
+		"slice with elems of differing Go types, same TOML types": {
+			input: struct {
+				MixedInts   []interface{}
+				MixedFloats []interface{}
+			}{
+				[]interface{}{
+					int(1), int8(2), int16(3), int32(4), int64(5),
+					uint(1), uint8(2), uint16(3), uint32(4), uint64(5),
+				},
+				[]interface{}{float32(1.5), float64(2.5)},
+			},
+			wantOutput: "MixedInts = [1, 2, 3, 4, 5, 1, 2, 3, 4, 5]\n" +
+				"MixedFloats = [1.5, 2.5]",
+		},
+		"(error) slice w/ element type mismatch (one is nested array)": {
+			input: struct{ Mixed []interface{} }{
+				[]interface{}{1, []interface{}{2}},
+			},
+			wantError: ErrArrayMixedElementTypes,
+		},
+		"(error) slice with 1 nil element": {
+			input:     struct{ NilElement1 []interface{} }{[]interface{}{nil}},
+			wantError: ErrArrayNilElement,
+		},
+		"(error) slice with 1 nil element (and other non-nil elements)": {
+			input: struct{ NilElement []interface{} }{
+				[]interface{}{1, nil},
+			},
+			wantError: ErrArrayNilElement,
+		},
+		"simple map": {
+			input:      map[string]int{"a": 1, "b": 2},
+			wantOutput: "a = 1\nb = 2",
+		},
+		"map with interface{} value type": {
+			input:      map[string]interface{}{"a": 1, "b": "c"},
+			wantOutput: "a = 1\nb = \"c\"",
+		},
+		"map with interface{} value type, some of which are structs": {
+			input: map[string]interface{}{
+				"a": struct{ Int int }{2},
+				"b": 1,
+			},
+			wantOutput: "b = 1\n[a]\n  Int = 2",
+		},
+		"nested map": {
+			input: map[string]map[string]int{
+				"a": map[string]int{"b": 1},
+				"c": map[string]int{"d": 2},
+			},
+			wantOutput: "[a]\n  b = 1\n\n[c]\n  d = 2",
+		},
+		"nested struct": {
+			input: struct{ Struct struct{ Int int } }{
+				struct{ Int int }{1},
+			},
+			wantOutput: "[Struct]\n  Int = 1",
+		},
+		"nested struct and non-struct field": {
+			input: struct {
+				Struct struct{ Int int }
+				Bool   bool
+			}{struct{ Int int }{1}, true},
+			wantOutput: "Bool = true\n\n[Struct]\n  Int = 1",
+		},
+		"2 nested structs": {
+			input: struct{ Struct1, Struct2 struct{ Int int } }{
+				struct{ Int int }{1}, struct{ Int int }{2},
+			},
+			wantOutput: "[Struct1]\n  Int = 1\n\n[Struct2]\n  Int = 2",
+		},
+		"deeply nested structs": {
+			input: struct {
+				Struct1, Struct2 struct{ Struct3 *struct{ Int int } }
+			}{
+				struct{ Struct3 *struct{ Int int } }{&struct{ Int int }{1}},
+				struct{ Struct3 *struct{ Int int } }{nil},
+			},
+			wantOutput: "[Struct1]\n  [Struct1.Struct3]\n    Int = 1" +
+				"\n\n[Struct2]\n",
+		},
+		"nested struct with nil struct elem": {
+			input: struct {
+				Struct struct{ Inner *struct{ Int int } }
+			}{
+				struct{ Inner *struct{ Int int } }{nil},
+			},
+			wantOutput: "[Struct]\n",
+		},
+		"nested struct with no fields": {
+			input: struct {
+				Struct struct{ Inner struct{} }
+			}{
+				struct{ Inner struct{} }{struct{}{}},
+			},
+			wantOutput: "[Struct]\n  [Struct.Inner]\n",
+		},
+		"struct with tags": {
+			input: struct {
+				Struct struct {
+					Int int `toml:"_int"`
+				} `toml:"_struct"`
+				Bool bool `toml:"_bool"`
+			}{
+				struct {
+					Int int `toml:"_int"`
+				}{1}, true,
+			},
+			wantOutput: "_bool = true\n\n[_struct]\n  _int = 1",
+		},
+		"embedded struct": {
+			input:      struct{ Embedded }{Embedded{1}},
+			wantOutput: "_int = 1",
+		},
+		"embedded *struct": {
+			input:      struct{ *Embedded }{&Embedded{1}},
+			wantOutput: "_int = 1",
+		},
+		"nested embedded struct": {
+			input: struct {
+				Struct struct{ Embedded } `toml:"_struct"`
+			}{struct{ Embedded }{Embedded{1}}},
+			wantOutput: "[_struct]\n  _int = 1",
+		},
+		"nested embedded *struct": {
+			input: struct {
+				Struct struct{ *Embedded } `toml:"_struct"`
+			}{struct{ *Embedded }{&Embedded{1}}},
+			wantOutput: "[_struct]\n  _int = 1",
+		},
+		"array of tables": {
+			input: struct {
+				Structs []*struct{ Int int } `toml:"struct"`
+			}{
+				[]*struct{ Int int }{
+					{1}, nil, {3},
+				},
+			},
+			wantOutput: "[[struct]]\n  Int = 1\n\n[[struct]]\n  Int = 3",
+		},
 	}
-
-	buf := new(bytes.Buffer)
-	e := newEncoder(buf)
-	if err := e.Encode(v); err != nil {
-		t.Fatal(err)
+	for label, test := range tests {
+		var buf bytes.Buffer
+		e := NewEncoder(&buf)
+		err := e.Encode(test.input)
+		if err != test.wantError {
+			if test.wantError != nil {
+				t.Errorf("%s: want Encode error %v, got %v",
+					label, test.wantError, err)
+			} else {
+				t.Errorf("%s: Encode failed: %s", label, err)
+			}
+		}
+		if err != nil {
+			continue
+		}
+		if got := buf.String(); test.wantOutput != got {
+			t.Errorf("%s: want %q, got %q", label, test.wantOutput, got)
+		}
 	}
-	testf(buf.String())
+}
+
+type Embedded struct {
+	Int int `toml:"_int"`
 }

third_party/github.com/BurntSushi/toml/parse.go

@@ -159,6 +159,8 @@ func (p *parser) value(it item) (interface{}, tomlType) {
 	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 {
 
@@ -172,6 +174,13 @@ func (p *parser) value(it item) (interface{}, tomlType) {
 	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 {
 
@@ -209,7 +218,8 @@ func (p *parser) value(it item) (interface{}, tomlType) {
 }
 
 // establishContext sets the current context of the parser,
-// where the context is the hash currently in scope.
+// 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.
@@ -248,10 +258,15 @@ func (p *parser) establishContext(key Key, array bool) {
 
 	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 {
@@ -280,6 +295,8 @@ func (p *parser) setValue(key string, value interface{}) {
 		}
 		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
@@ -291,9 +308,17 @@ func (p *parser) setValue(key string, value interface{}) {
 	keyContext = append(keyContext, key)
 
 	if _, ok := hash[key]; ok {
-		// We need to do some fancy footwork here. If `hash[key]` was implcitly
-		// created AND `value` is a hash, then let this go through and stop
-		// tagging this table as implicit.
+		// 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
@@ -308,6 +333,9 @@ func (p *parser) setValue(key string, value interface{}) {
 
 // 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 {
@@ -377,9 +405,10 @@ func (p *parser) asciiEscapeToUnicode(s string) string {
 			"lexer claims it's OK: %s", s, err)
 	}
 
-	// I honestly don't understand how this works. I can't seem to find
-	// a way to make this fail. I figured this would fail on invalid UTF-8
-	// characters like U+DCFF, but it doesn't.
+	// BUG(burntsushi)
+	// I honestly don't understand how this works. I can't seem
+	// to find a way to make this fail. I figured this would fail on invalid
+	// UTF-8 characters like U+DCFF, but it doesn't.
 	r := string(rune(hex))
 	if !utf8.ValidString(r) {
 		p.panic("Escaped character '\\u%s' is not valid UTF-8.", s)

third_party/github.com/BurntSushi/toml/toml-test-encoder/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.
+

third_party/github.com/BurntSushi/toml/toml-test-encoder/README.md

@@ -0,0 +1,14 @@
+# Implements the TOML test suite interface for TOML encoders
+
+This is an implementation of the interface expected by
+[toml-test](https://github.com/BurntSushi/toml-test) for the
+[TOML encoder](https://github.com/BurntSushi/toml).
+In particular, it maps JSON data on `stdin` to a TOML format on `stdout`.
+
+
+Compatible with TOML version
+[v0.2.0](https://github.com/mojombo/toml/blob/master/versions/toml-v0.2.0.md)
+
+Compatible with `toml-test` version
+[v0.2.0](https://github.com/BurntSushi/toml-test/tree/v0.2.0)
+

third_party/github.com/BurntSushi/toml/toml-test-encoder/main.go

@@ -0,0 +1,129 @@
+package main
+
+import (
+	"encoding/json"
+	"flag"
+	"log"
+	"os"
+	"path"
+	"strconv"
+	"time"
+
+	"github.com/BurntSushi/toml"
+)
+
+func init() {
+	log.SetFlags(0)
+
+	flag.Usage = usage
+	flag.Parse()
+}
+
+func usage() {
+	log.Printf("Usage: %s < json-file\n", path.Base(os.Args[0]))
+	flag.PrintDefaults()
+
+	os.Exit(1)
+}
+
+func main() {
+	if flag.NArg() != 0 {
+		flag.Usage()
+	}
+
+	var tmp interface{}
+	if err := json.NewDecoder(os.Stdin).Decode(&tmp); err != nil {
+		log.Fatalf("Error decoding JSON: %s", err)
+	}
+
+	tomlData := translate(tmp)
+	if err := toml.NewEncoder(os.Stdout).Encode(tomlData); err != nil {
+		log.Fatalf("Error encoding TOML: %s", err)
+	}
+}
+
+func translate(typedJson interface{}) interface{} {
+	switch v := typedJson.(type) {
+	case map[string]interface{}:
+		if len(v) == 2 && in("type", v) && in("value", v) {
+			return untag(v)
+		}
+		m := make(map[string]interface{}, len(v))
+		for k, v2 := range v {
+			m[k] = translate(v2)
+		}
+		return m
+	case []interface{}:
+		tabArray := make([]map[string]interface{}, len(v))
+		for i := range v {
+			if m, ok := translate(v[i]).(map[string]interface{}); ok {
+				tabArray[i] = m
+			} else {
+				log.Fatalf("JSON arrays may only contain objects. This "+
+					"corresponds to only tables being allowed in "+
+					"TOML table arrays.")
+			}
+		}
+		return tabArray
+	}
+	log.Fatalf("Unrecognized JSON format '%T'.", typedJson)
+	panic("unreachable")
+}
+
+func untag(typed map[string]interface{}) interface{} {
+	t := typed["type"].(string)
+	v := typed["value"]
+	switch t {
+	case "string":
+		return v.(string)
+	case "integer":
+		v := v.(string)
+		n, err := strconv.Atoi(v)
+		if err != nil {
+			log.Fatalf("Could not parse '%s' as integer: %s", v, err)
+		}
+		return n
+	case "float":
+		v := v.(string)
+		f, err := strconv.ParseFloat(v, 64)
+		if err != nil {
+			log.Fatalf("Could not parse '%s' as float64: %s", v, err)
+		}
+		return f
+	case "datetime":
+		v := v.(string)
+		t, err := time.Parse("2006-01-02T15:04:05Z", v)
+		if err != nil {
+			log.Fatalf("Could not parse '%s' as a datetime: %s", v, err)
+		}
+		return t
+	case "bool":
+		v := v.(string)
+		switch v {
+		case "true":
+			return true
+		case "false":
+			return false
+		}
+		log.Fatalf("Could not parse '%s' as a boolean.", v)
+	case "array":
+		v := v.([]interface{})
+		array := make([]interface{}, len(v))
+		for i := range v {
+			if m, ok := v[i].(map[string]interface{}); ok {
+				array[i] = untag(m)
+			} else {
+				log.Fatalf("Arrays may only contain other arrays or "+
+					"primitive values, but found a '%T'.", m)
+			}
+		}
+		return array
+	}
+	log.Fatalf("Unrecognized tag type '%s'.", t)
+	panic("unreachable")
+}
+
+func in(key string, m map[string]interface{}) bool {
+	_, ok := m[key]
+	return ok
+}

third_party/github.com/BurntSushi/toml/toml-test-go/main.go

@@ -43,7 +43,6 @@ func main() {
 }
 
 func translate(tomlData interface{}) interface{} {
-
 	switch orig := tomlData.(type) {
 	case map[string]interface{}:
 		typed := make(map[string]interface{}, len(orig))

third_party/github.com/BurntSushi/toml/type_check.go

@@ -0,0 +1,78 @@
+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 {
+	return t1.typeString() == t2.typeString()
+}
+
+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 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.panic("Array contains values of type '%s' and '%s', but arrays "+
+				"must be homogeneous.", theType, t)
+		}
+	}
+	return tomlArray
+}

third_party/github.com/BurntSushi/toml/type_fields.go

@@ -14,10 +14,10 @@ import (
 
 // A field represents a single field found in a struct.
 type field struct {
-	name  string
-	tag   bool
-	index []int
-	typ   reflect.Type
+	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,