TUN-6724: Migrate to sentry-go from raven-go

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

@@ -2,57 +2,127 @@ package toml
 
 import (
 	"bufio"
+	"encoding"
+	"encoding/json"
 	"errors"
 	"fmt"
 	"io"
+	"math"
 	"reflect"
 	"sort"
 	"strconv"
 	"strings"
 	"time"
+
+	"github.com/BurntSushi/toml/internal"
 )
 
 type tomlEncodeError struct{ error }
 
 var (
-	errArrayMixedElementTypes = errors.New(
-		"toml: cannot encode array with mixed element types")
-	errArrayNilElement = errors.New(
-		"toml: cannot encode array with nil element")
-	errNonString = errors.New(
-		"toml: cannot encode a map with non-string key type")
-	errAnonNonStruct = errors.New(
-		"toml: cannot encode an anonymous field that is not a struct")
-	errArrayNoTable = errors.New(
-		"toml: TOML array element cannot contain a table")
-	errNoKey = errors.New(
-		"toml: top-level values must be Go maps or structs")
-	errAnything = errors.New("") // used in testing
+	errArrayNilElement = errors.New("toml: cannot encode array with nil element")
+	errNonString       = errors.New("toml: cannot encode a map with non-string key type")
+	errNoKey           = errors.New("toml: top-level values must be Go maps or structs")
+	errAnything        = errors.New("") // used in testing
 )
 
-var quotedReplacer = strings.NewReplacer(
-	"\t", "\\t",
-	"\n", "\\n",
-	"\r", "\\r",
+var dblQuotedReplacer = strings.NewReplacer(
 	"\"", "\\\"",
 	"\\", "\\\\",
+	"\x00", `\u0000`,
+	"\x01", `\u0001`,
+	"\x02", `\u0002`,
+	"\x03", `\u0003`,
+	"\x04", `\u0004`,
+	"\x05", `\u0005`,
+	"\x06", `\u0006`,
+	"\x07", `\u0007`,
+	"\b", `\b`,
+	"\t", `\t`,
+	"\n", `\n`,
+	"\x0b", `\u000b`,
+	"\f", `\f`,
+	"\r", `\r`,
+	"\x0e", `\u000e`,
+	"\x0f", `\u000f`,
+	"\x10", `\u0010`,
+	"\x11", `\u0011`,
+	"\x12", `\u0012`,
+	"\x13", `\u0013`,
+	"\x14", `\u0014`,
+	"\x15", `\u0015`,
+	"\x16", `\u0016`,
+	"\x17", `\u0017`,
+	"\x18", `\u0018`,
+	"\x19", `\u0019`,
+	"\x1a", `\u001a`,
+	"\x1b", `\u001b`,
+	"\x1c", `\u001c`,
+	"\x1d", `\u001d`,
+	"\x1e", `\u001e`,
+	"\x1f", `\u001f`,
+	"\x7f", `\u007f`,
 )
 
-// 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
+var (
+	marshalToml = reflect.TypeOf((*Marshaler)(nil)).Elem()
+	marshalText = reflect.TypeOf((*encoding.TextMarshaler)(nil)).Elem()
+	timeType    = reflect.TypeOf((*time.Time)(nil)).Elem()
+)
 
-	// hasWritten is whether we have written any output to w yet.
-	hasWritten bool
-	w          *bufio.Writer
+// Marshaler is the interface implemented by types that can marshal themselves
+// into valid TOML.
+type Marshaler interface {
+	MarshalTOML() ([]byte, error)
 }
 
-// NewEncoder returns a TOML encoder that encodes Go values to the io.Writer
-// given. By default, a single indentation level is 2 spaces.
+// Encoder encodes a Go to a TOML document.
+//
+// The mapping between Go values and TOML values should be precisely the same as
+// for the Decode* functions.
+//
+// time.Time is encoded as a RFC 3339 string, and time.Duration as its string
+// representation.
+//
+// The toml.Marshaler and encoder.TextMarshaler interfaces are supported to
+// encoding the value as custom TOML.
+//
+// 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 (Go maps or structs), keys without any sub-hashes
+// are encoded first.
+//
+// Go maps will be sorted alphabetically by key for deterministic output.
+//
+// The toml struct tag can be used to provide the key name; if omitted the
+// struct field name will be used. If the "omitempty" option is present the
+// following value will be skipped:
+//
+//   - arrays, slices, maps, and string with len of 0
+//   - struct with all zero values
+//   - bool false
+//
+// If omitzero is given all int and float types with a value of 0 will be
+// skipped.
+//
+// Encoding Go values without a corresponding TOML representation will return an
+// error. Examples of this includes maps with non-string keys, 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 okay, as is []map[string][]string).
+//
+// NOTE: only exported keys are encoded due to the use of reflection. Unexported
+// keys are silently discarded.
+type Encoder struct {
+	// String to use for a single indentation level; default is two spaces.
+	Indent string
+
+	w          *bufio.Writer
+	hasWritten bool // written any output to w yet?
+}
+
+// NewEncoder create a new Encoder.
 func NewEncoder(w io.Writer) *Encoder {
 	return &Encoder{
 		w:      bufio.NewWriter(w),
@@ -60,29 +130,10 @@ func NewEncoder(w io.Writer) *Encoder {
 	}
 }
 
-// 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.
+// Encode writes a TOML representation of the Go value to the Encoder's writer.
 //
-// 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.)
+// An error is returned if the value given cannot be encoded to a valid TOML
+// document.
 func (enc *Encoder) Encode(v interface{}) error {
 	rv := eindirect(reflect.ValueOf(v))
 	if err := enc.safeEncode(Key([]string{}), rv); err != nil {
@@ -106,13 +157,15 @@ func (enc *Encoder) safeEncode(key Key, rv reflect.Value) (err error) {
 }
 
 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)
+	// If we can marshal the type to text, then we use that. This prevents the
+	// encoder for handling these types as generic structs (or whatever the
+	// underlying type of a TextMarshaler is).
+	switch {
+	case isMarshaler(rv):
+		enc.writeKeyValue(key, rv, false)
+		return
+	case rv.Type() == primitiveType: // TODO: #76 would make this superfluous after implemented.
+		enc.encode(key, reflect.ValueOf(rv.Interface().(Primitive).undecoded))
 		return
 	}
 
@@ -123,12 +176,12 @@ func (enc *Encoder) encode(key Key, rv reflect.Value) {
 		reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32,
 		reflect.Uint64,
 		reflect.Float32, reflect.Float64, reflect.String, reflect.Bool:
-		enc.keyEqElement(key, rv)
+		enc.writeKeyValue(key, rv, false)
 	case reflect.Array, reflect.Slice:
 		if typeEqual(tomlArrayHash, tomlTypeOfGo(rv)) {
 			enc.eArrayOfTables(key, rv)
 		} else {
-			enc.keyEqElement(key, rv)
+			enc.writeKeyValue(key, rv, false)
 		}
 	case reflect.Interface:
 		if rv.IsNil() {
@@ -148,55 +201,114 @@ func (enc *Encoder) encode(key Key, rv reflect.Value) {
 	case reflect.Struct:
 		enc.eTable(key, rv)
 	default:
-		panic(e("unsupported type for key '%s': %s", key, k))
+		encPanic(fmt.Errorf("unsupported type for key '%s': %s", key, k))
 	}
 }
 
-// eElement encodes any value that can be an array element (primitives and
-// arrays).
+// eElement encodes any value that can be an array element.
 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.UTC().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))
+	case time.Time: // Using TextMarshaler adds extra quotes, which we don't want.
+		format := time.RFC3339Nano
+		switch v.Location() {
+		case internal.LocalDatetime:
+			format = "2006-01-02T15:04:05.999999999"
+		case internal.LocalDate:
+			format = "2006-01-02"
+		case internal.LocalTime:
+			format = "15:04:05.999999999"
+		}
+		switch v.Location() {
+		default:
+			enc.wf(v.Format(format))
+		case internal.LocalDatetime, internal.LocalDate, internal.LocalTime:
+			enc.wf(v.In(time.UTC).Format(format))
 		}
 		return
+	case Marshaler:
+		s, err := v.MarshalTOML()
+		if err != nil {
+			encPanic(err)
+		}
+		if s == nil {
+			encPanic(errors.New("MarshalTOML returned nil and no error"))
+		}
+		enc.w.Write(s)
+		return
+	case encoding.TextMarshaler:
+		s, err := v.MarshalText()
+		if err != nil {
+			encPanic(err)
+		}
+		if s == nil {
+			encPanic(errors.New("MarshalText returned nil and no error"))
+		}
+		enc.writeQuoted(string(s))
+		return
+	case time.Duration:
+		enc.writeQuoted(v.String())
+		return
+	case json.Number:
+		n, _ := rv.Interface().(json.Number)
+
+		if n == "" { /// Useful zero value.
+			enc.w.WriteByte('0')
+			return
+		} else if v, err := n.Int64(); err == nil {
+			enc.eElement(reflect.ValueOf(v))
+			return
+		} else if v, err := n.Float64(); err == nil {
+			enc.eElement(reflect.ValueOf(v))
+			return
+		}
+		encPanic(errors.New(fmt.Sprintf("Unable to convert \"%s\" to neither int64 nor float64", n)))
 	}
+
 	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:
+	case reflect.Ptr:
 		enc.eElement(rv.Elem())
+		return
 	case reflect.String:
 		enc.writeQuoted(rv.String())
+	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:
+		f := rv.Float()
+		if math.IsNaN(f) {
+			enc.wf("nan")
+		} else if math.IsInf(f, 0) {
+			enc.wf("%cinf", map[bool]byte{true: '-', false: '+'}[math.Signbit(f)])
+		} else {
+			enc.wf(floatAddDecimal(strconv.FormatFloat(f, 'f', -1, 32)))
+		}
+	case reflect.Float64:
+		f := rv.Float()
+		if math.IsNaN(f) {
+			enc.wf("nan")
+		} else if math.IsInf(f, 0) {
+			enc.wf("%cinf", map[bool]byte{true: '-', false: '+'}[math.Signbit(f)])
+		} else {
+			enc.wf(floatAddDecimal(strconv.FormatFloat(f, 'f', -1, 64)))
+		}
+	case reflect.Array, reflect.Slice:
+		enc.eArrayOrSliceElement(rv)
+	case reflect.Struct:
+		enc.eStruct(nil, rv, true)
+	case reflect.Map:
+		enc.eMap(nil, rv, true)
+	case reflect.Interface:
+		enc.eElement(rv.Elem())
 	default:
-		panic(e("unexpected primitive type: %s", rv.Kind()))
+		encPanic(fmt.Errorf("unexpected type: %T", rv.Interface()))
 	}
 }
 
-// By the TOML spec, all floats must have a decimal with at least one
-// number on either side.
+// 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"
@@ -205,14 +317,14 @@ func floatAddDecimal(fstr string) string {
 }
 
 func (enc *Encoder) writeQuoted(s string) {
-	enc.wf("\"%s\"", quotedReplacer.Replace(s))
+	enc.wf("\"%s\"", dblQuotedReplacer.Replace(s))
 }
 
 func (enc *Encoder) eArrayOrSliceElement(rv reflect.Value) {
 	length := rv.Len()
 	enc.wf("[")
 	for i := 0; i < length; i++ {
-		elem := rv.Index(i)
+		elem := eindirect(rv.Index(i))
 		enc.eElement(elem)
 		if i != length-1 {
 			enc.wf(", ")
@@ -226,44 +338,43 @@ func (enc *Encoder) eArrayOfTables(key Key, rv reflect.Value) {
 		encPanic(errNoKey)
 	}
 	for i := 0; i < rv.Len(); i++ {
-		trv := rv.Index(i)
+		trv := eindirect(rv.Index(i))
 		if isNil(trv) {
 			continue
 		}
-		panicIfInvalidKey(key)
 		enc.newline()
-		enc.wf("%s[[%s]]", enc.indentStr(key), key.maybeQuotedAll())
+		enc.wf("%s[[%s]]", enc.indentStr(key), key)
 		enc.newline()
-		enc.eMapOrStruct(key, trv)
+		enc.eMapOrStruct(key, trv, false)
 	}
 }
 
 func (enc *Encoder) eTable(key Key, rv reflect.Value) {
-	panicIfInvalidKey(key)
 	if len(key) == 1 {
 		// Output an extra newline 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.wf("%s[%s]", enc.indentStr(key), key)
 		enc.newline()
 	}
-	enc.eMapOrStruct(key, rv)
+	enc.eMapOrStruct(key, rv, false)
 }
 
-func (enc *Encoder) eMapOrStruct(key Key, rv reflect.Value) {
-	switch rv := eindirect(rv); rv.Kind() {
+func (enc *Encoder) eMapOrStruct(key Key, rv reflect.Value, inline bool) {
+	switch rv.Kind() {
 	case reflect.Map:
-		enc.eMap(key, rv)
+		enc.eMap(key, rv, inline)
 	case reflect.Struct:
-		enc.eStruct(key, rv)
+		enc.eStruct(key, rv, inline)
 	default:
+		// Should never happen?
 		panic("eTable: unhandled reflect.Value Kind: " + rv.Kind().String())
 	}
 }
 
-func (enc *Encoder) eMap(key Key, rv reflect.Value) {
+func (enc *Encoder) eMap(key Key, rv reflect.Value, inline bool) {
 	rt := rv.Type()
 	if rt.Key().Kind() != reflect.String {
 		encPanic(errNonString)
@@ -274,118 +385,179 @@ func (enc *Encoder) eMap(key Key, rv reflect.Value) {
 	var mapKeysDirect, mapKeysSub []string
 	for _, mapKey := range rv.MapKeys() {
 		k := mapKey.String()
-		if typeIsHash(tomlTypeOfGo(rv.MapIndex(mapKey))) {
+		if typeIsTable(tomlTypeOfGo(eindirect(rv.MapIndex(mapKey)))) {
 			mapKeysSub = append(mapKeysSub, k)
 		} else {
 			mapKeysDirect = append(mapKeysDirect, k)
 		}
 	}
 
-	var writeMapKeys = func(mapKeys []string) {
+	var writeMapKeys = func(mapKeys []string, trailC bool) {
 		sort.Strings(mapKeys)
-		for _, mapKey := range mapKeys {
-			mrv := rv.MapIndex(reflect.ValueOf(mapKey))
-			if isNil(mrv) {
-				// Don't write anything for nil fields.
+		for i, mapKey := range mapKeys {
+			val := eindirect(rv.MapIndex(reflect.ValueOf(mapKey)))
+			if isNil(val) {
 				continue
 			}
-			enc.encode(key.add(mapKey), mrv)
+
+			if inline {
+				enc.writeKeyValue(Key{mapKey}, val, true)
+				if trailC || i != len(mapKeys)-1 {
+					enc.wf(", ")
+				}
+			} else {
+				enc.encode(key.add(mapKey), val)
+			}
 		}
 	}
-	writeMapKeys(mapKeysDirect)
-	writeMapKeys(mapKeysSub)
+
+	if inline {
+		enc.wf("{")
+	}
+	writeMapKeys(mapKeysDirect, len(mapKeysSub) > 0)
+	writeMapKeys(mapKeysSub, false)
+	if inline {
+		enc.wf("}")
+	}
 }
 
-func (enc *Encoder) eStruct(key Key, rv reflect.Value) {
+const is32Bit = (32 << (^uint(0) >> 63)) == 32
+
+func pointerTo(t reflect.Type) reflect.Type {
+	if t.Kind() == reflect.Ptr {
+		return pointerTo(t.Elem())
+	}
+	return t
+}
+
+func (enc *Encoder) eStruct(key Key, rv reflect.Value, inline bool) {
 	// 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
+	// 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)
+	//
+	// Fields is a [][]int: for fieldsDirect this always has one entry (the
+	// struct index). For fieldsSub it contains two entries: the parent field
+	// index from tv, and the field indexes for the fields of the sub.
+	var (
+		rt                      = rv.Type()
+		fieldsDirect, fieldsSub [][]int
+		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 {
+			isEmbed := f.Anonymous && pointerTo(f.Type).Kind() == reflect.Struct
+			if f.PkgPath != "" && !isEmbed { /// Skip unexported fields.
 				continue
 			}
-			frv := rv.Field(i)
-			if f.Anonymous {
-				t := f.Type
-				switch t.Kind() {
-				case reflect.Struct:
-					// Treat anonymous struct fields with
-					// tag names as though they are not
-					// anonymous, like encoding/json does.
-					if getOptions(f.Tag).name == "" {
-						addFields(t, frv, f.Index)
-						continue
-					}
-				case reflect.Ptr:
-					if t.Elem().Kind() == reflect.Struct &&
-						getOptions(f.Tag).name == "" {
-						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.
+			opts := getOptions(f.Tag)
+			if opts.skip {
+				continue
+			}
+
+			frv := eindirect(rv.Field(i))
+
+			// Treat anonymous struct fields with tag names as though they are
+			// not anonymous, like encoding/json does.
+			//
+			// Non-struct anonymous fields use the normal encoding logic.
+			if isEmbed {
+				if getOptions(f.Tag).name == "" && frv.Kind() == reflect.Struct {
+					addFields(frv.Type(), frv, append(start, f.Index...))
+					continue
 				}
 			}
 
-			if typeIsHash(tomlTypeOfGo(frv)) {
+			if typeIsTable(tomlTypeOfGo(frv)) {
 				fieldsSub = append(fieldsSub, append(start, f.Index...))
 			} else {
-				fieldsDirect = append(fieldsDirect, append(start, f.Index...))
+				// Copy so it works correct on 32bit archs; not clear why this
+				// is needed. See #314, and https://www.reddit.com/r/golang/comments/pnx8v4
+				// This also works fine on 64bit, but 32bit archs are somewhat
+				// rare and this is a wee bit faster.
+				if is32Bit {
+					copyStart := make([]int, len(start))
+					copy(copyStart, start)
+					fieldsDirect = append(fieldsDirect, append(copyStart, f.Index...))
+				} else {
+					fieldsDirect = append(fieldsDirect, append(start, f.Index...))
+				}
 			}
 		}
 	}
 	addFields(rt, rv, nil)
 
-	var writeFields = func(fields [][]int) {
+	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.
+			fieldType := rt.FieldByIndex(fieldIndex)
+			fieldVal := eindirect(rv.FieldByIndex(fieldIndex))
+
+			if isNil(fieldVal) { /// Don't write anything for nil fields.
 				continue
 			}
 
-			opts := getOptions(sft.Tag)
+			opts := getOptions(fieldType.Tag)
 			if opts.skip {
 				continue
 			}
-			keyName := sft.Name
+			keyName := fieldType.Name
 			if opts.name != "" {
 				keyName = opts.name
 			}
-			if opts.omitempty && isEmpty(sf) {
+			if opts.omitempty && isEmpty(fieldVal) {
 				continue
 			}
-			if opts.omitzero && isZero(sf) {
+			if opts.omitzero && isZero(fieldVal) {
 				continue
 			}
 
-			enc.encode(key.add(keyName), sf)
+			if inline {
+				enc.writeKeyValue(Key{keyName}, fieldVal, true)
+				if fieldIndex[0] != len(fields)-1 {
+					enc.wf(", ")
+				}
+			} else {
+				enc.encode(key.add(keyName), fieldVal)
+			}
 		}
 	}
+
+	if inline {
+		enc.wf("{")
+	}
 	writeFields(fieldsDirect)
 	writeFields(fieldsSub)
+	if inline {
+		enc.wf("}")
+	}
 }
 
-// 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.
+// tomlTypeOfGo 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.
+//
+// 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
 	}
+
+	if rv.Kind() == reflect.Struct {
+		if rv.Type() == timeType {
+			return tomlDatetime
+		}
+		if isMarshaler(rv) {
+			return tomlString
+		}
+		return tomlHash
+	}
+
+	if isMarshaler(rv) {
+		return tomlString
+	}
+
 	switch rv.Kind() {
 	case reflect.Bool:
 		return tomlBool
@@ -397,7 +569,7 @@ func tomlTypeOfGo(rv reflect.Value) tomlType {
 	case reflect.Float32, reflect.Float64:
 		return tomlFloat
 	case reflect.Array, reflect.Slice:
-		if typeEqual(tomlHash, tomlArrayType(rv)) {
+		if isTableArray(rv) {
 			return tomlArrayHash
 		}
 		return tomlArray
@@ -407,54 +579,35 @@ func tomlTypeOfGo(rv reflect.Value) tomlType {
 		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())
+		encPanic(errors.New("unsupported type: " + rv.Kind().String()))
+		panic("unreachable")
 	}
 }
 
-// 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)
+func isMarshaler(rv reflect.Value) bool {
+	return rv.Type().Implements(marshalText) || rv.Type().Implements(marshalToml)
+}
+
+// isTableArray reports if all entries in the array or slice are a table.
+func isTableArray(arr reflect.Value) bool {
+	if isNil(arr) || !arr.IsValid() || arr.Len() == 0 {
+		return false
 	}
 
-	rvlen := rv.Len()
-	for i := 1; i < rvlen; i++ {
-		elem := rv.Index(i)
-		switch elemType := tomlTypeOfGo(elem); {
-		case elemType == nil:
+	ret := true
+	for i := 0; i < arr.Len(); i++ {
+		tt := tomlTypeOfGo(eindirect(arr.Index(i)))
+		// Don't allow nil.
+		if tt == nil {
 			encPanic(errArrayNilElement)
-		case !typeEqual(firstType, elemType):
-			encPanic(errArrayMixedElementTypes)
+		}
+
+		if ret && !typeEqual(tomlHash, tt) {
+			ret = false
 		}
 	}
-	// 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
+	return ret
 }
 
 type tagOptions struct {
@@ -499,6 +652,8 @@ func isEmpty(rv reflect.Value) bool {
 	switch rv.Kind() {
 	case reflect.Array, reflect.Slice, reflect.Map, reflect.String:
 		return rv.Len() == 0
+	case reflect.Struct:
+		return reflect.Zero(rv.Type()).Interface() == rv.Interface()
 	case reflect.Bool:
 		return !rv.Bool()
 	}
@@ -511,18 +666,32 @@ func (enc *Encoder) newline() {
 	}
 }
 
-func (enc *Encoder) keyEqElement(key Key, val reflect.Value) {
+// Write a key/value pair:
+//
+//   key = <any value>
+//
+// This is also used for "k = v" in inline tables; so something like this will
+// be written in three calls:
+//
+//     ┌────────────────────┐
+//     │      ┌───┐  ┌─────┐│
+//     v      v   v  v     vv
+//     key = {k = v, k2 = v2}
+//
+func (enc *Encoder) writeKeyValue(key Key, val reflect.Value, inline bool) {
 	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()
+	if !inline {
+		enc.newline()
+	}
 }
 
 func (enc *Encoder) wf(format string, v ...interface{}) {
-	if _, err := fmt.Fprintf(enc.w, format, v...); err != nil {
+	_, err := fmt.Fprintf(enc.w, format, v...)
+	if err != nil {
 		encPanic(err)
 	}
 	enc.hasWritten = true
@@ -536,13 +705,25 @@ func encPanic(err error) {
 	panic(tomlEncodeError{err})
 }
 
+// Resolve any level of pointers to the actual value (e.g. **string → string).
 func eindirect(v reflect.Value) reflect.Value {
-	switch v.Kind() {
-	case reflect.Ptr, reflect.Interface:
-		return eindirect(v.Elem())
-	default:
+	if v.Kind() != reflect.Ptr && v.Kind() != reflect.Interface {
+		if isMarshaler(v) {
+			return v
+		}
+		if v.CanAddr() { /// Special case for marshalers; see #358.
+			if pv := v.Addr(); isMarshaler(pv) {
+				return pv
+			}
+		}
 		return v
 	}
+
+	if v.IsNil() {
+		return v
+	}
+
+	return eindirect(v.Elem())
 }
 
 func isNil(rv reflect.Value) bool {
@@ -553,16 +734,3 @@ func isNil(rv reflect.Value) bool {
 		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
-}