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path: root/vendor/github.com/BurntSushi/toml/encode.go
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-rw-r--r--vendor/github.com/BurntSushi/toml/encode.go549
1 files changed, 549 insertions, 0 deletions
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
+}