Adding upstream version 1.3.2.upstream/1.3.2upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 602 insertions, 0 deletions

diff --git a/decode.go b/decode.go
new file mode 100644
index 0000000..4d38f3b
--- /dev/null
+++ b/decode.go
@@ -0,0 +1,602 @@
+package toml
+
+import (
+	"bytes"
+	"encoding"
+	"encoding/json"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"math"
+	"os"
+	"reflect"
+	"strconv"
+	"strings"
+	"time"
+)
+
+// 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 data in TOML format into a pointer v.
+//
+// See [Decoder] for a description of the decoding process.
+func Unmarshal(data []byte, v interface{}) error {
+	_, err := NewDecoder(bytes.NewReader(data)).Decode(v)
+	return err
+}
+
+// Decode the TOML data in to the pointer v.
+//
+// See [Decoder] for a description of the decoding process.
+func Decode(data string, v interface{}) (MetaData, error) {
+	return NewDecoder(strings.NewReader(data)).Decode(v)
+}
+
+// DecodeFile reads the contents of a file and decodes it with [Decode].
+func DecodeFile(path string, v interface{}) (MetaData, error) {
+	fp, err := os.Open(path)
+	if err != nil {
+		return MetaData{}, err
+	}
+	defer fp.Close()
+	return NewDecoder(fp).Decode(v)
+}
+
+// Primitive is a TOML value that hasn't been decoded into a Go value.
+//
+// This type can be used for any value, which will cause decoding to be delayed.
+// You can use [PrimitiveDecode] to "manually" decode these values.
+//
+// NOTE: The underlying representation of a `Primitive` value is subject to
+// change. Do not rely on it.
+//
+// NOTE: 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 runtime.
+type Primitive struct {
+	undecoded interface{}
+	context   Key
+}
+
+// The significand precision for float32 and float64 is 24 and 53 bits; this is
+// the range a natural number can be stored in a float without loss of data.
+const (
+	maxSafeFloat32Int = 16777215                // 2^24-1
+	maxSafeFloat64Int = int64(9007199254740991) // 2^53-1
+)
+
+// Decoder decodes TOML data.
+//
+// TOML tables correspond to Go structs or maps; they can be used
+// interchangeably, but structs offer better type safety.
+//
+// TOML table arrays correspond to either a slice of structs or a slice of maps.
+//
+// TOML datetimes correspond to [time.Time]. Local datetimes are parsed in the
+// local timezone.
+//
+// [time.Duration] types are treated as nanoseconds if the TOML value is an
+// integer, or they're parsed with time.ParseDuration() if they're strings.
+//
+// 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 TextUnmarshaler
+// interface, in which case any primitive TOML value (floats, strings, integers,
+// booleans, datetimes) will be converted to a []byte and given to the value's
+// UnmarshalText method. See the Unmarshaler example for a demonstration with
+// email addresses.
+//
+// # 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 can 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 does not handle cyclic types. Decode will not terminate if a
+// cyclic type is passed.
+type Decoder struct {
+	r io.Reader
+}
+
+// NewDecoder creates a new Decoder.
+func NewDecoder(r io.Reader) *Decoder {
+	return &Decoder{r: r}
+}
+
+var (
+	unmarshalToml = reflect.TypeOf((*Unmarshaler)(nil)).Elem()
+	unmarshalText = reflect.TypeOf((*encoding.TextUnmarshaler)(nil)).Elem()
+	primitiveType = reflect.TypeOf((*Primitive)(nil)).Elem()
+)
+
+// Decode TOML data in to the pointer `v`.
+func (dec *Decoder) Decode(v interface{}) (MetaData, error) {
+	rv := reflect.ValueOf(v)
+	if rv.Kind() != reflect.Ptr {
+		s := "%q"
+		if reflect.TypeOf(v) == nil {
+			s = "%v"
+		}
+
+		return MetaData{}, fmt.Errorf("toml: cannot decode to non-pointer "+s, reflect.TypeOf(v))
+	}
+	if rv.IsNil() {
+		return MetaData{}, fmt.Errorf("toml: cannot decode to nil value of %q", reflect.TypeOf(v))
+	}
+
+	// Check if this is a supported type: struct, map, interface{}, or something
+	// that implements UnmarshalTOML or UnmarshalText.
+	rv = indirect(rv)
+	rt := rv.Type()
+	if rv.Kind() != reflect.Struct && rv.Kind() != reflect.Map &&
+		!(rv.Kind() == reflect.Interface && rv.NumMethod() == 0) &&
+		!rt.Implements(unmarshalToml) && !rt.Implements(unmarshalText) {
+		return MetaData{}, fmt.Errorf("toml: cannot decode to type %s", rt)
+	}
+
+	// TODO: parser should read from io.Reader? Or at the very least, make it
+	// read from []byte rather than string
+	data, err := ioutil.ReadAll(dec.r)
+	if err != nil {
+		return MetaData{}, err
+	}
+
+	p, err := parse(string(data))
+	if err != nil {
+		return MetaData{}, err
+	}
+
+	md := MetaData{
+		mapping: p.mapping,
+		keyInfo: p.keyInfo,
+		keys:    p.ordered,
+		decoded: make(map[string]struct{}, len(p.ordered)),
+		context: nil,
+		data:    data,
+	}
+	return md, md.unify(p.mapping, rv)
+}
+
+// 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))
+}
+
+// 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.
+	// TODO: #76 would make this superfluous after implemented.
+	if rv.Type() == primitiveType {
+		// 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
+	}
+
+	rvi := rv.Interface()
+	if v, ok := rvi.(Unmarshaler); ok {
+		return v.UnmarshalTOML(data)
+	}
+	if v, ok := rvi.(encoding.TextUnmarshaler); ok {
+		return md.unifyText(data, v)
+	}
+
+	// TODO:
+	// 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()
+
+	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:
+		if rv.NumMethod() > 0 { /// Only empty interfaces are supported.
+			return md.e("unsupported type %s", rv.Type())
+		}
+		return md.unifyAnything(data, rv)
+	case reflect.Float32, reflect.Float64:
+		return md.unifyFloat64(data, rv)
+	}
+	return md.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 md.e("type mismatch for %s: expected table but found %T",
+			rv.Type().String(), 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()] = struct{}{}
+				md.context = append(md.context, key)
+
+				err := md.unify(datum, subv)
+				if err != nil {
+					return err
+				}
+				md.context = md.context[0 : len(md.context)-1]
+			} else if f.name != "" {
+				return md.e("cannot write unexported field %s.%s", rv.Type().String(), f.name)
+			}
+		}
+	}
+	return nil
+}
+
+func (md *MetaData) unifyMap(mapping interface{}, rv reflect.Value) error {
+	keyType := rv.Type().Key().Kind()
+	if keyType != reflect.String && keyType != reflect.Interface {
+		return fmt.Errorf("toml: cannot decode to a map with non-string key type (%s in %q)",
+			keyType, rv.Type())
+	}
+
+	tmap, ok := mapping.(map[string]interface{})
+	if !ok {
+		if tmap == nil {
+			return nil
+		}
+		return md.badtype("map", mapping)
+	}
+	if rv.IsNil() {
+		rv.Set(reflect.MakeMap(rv.Type()))
+	}
+	for k, v := range tmap {
+		md.decoded[md.context.add(k).String()] = struct{}{}
+		md.context = append(md.context, k)
+
+		rvval := reflect.Indirect(reflect.New(rv.Type().Elem()))
+
+		err := md.unify(v, indirect(rvval))
+		if err != nil {
+			return err
+		}
+		md.context = md.context[0 : len(md.context)-1]
+
+		rvkey := indirect(reflect.New(rv.Type().Key()))
+
+		switch keyType {
+		case reflect.Interface:
+			rvkey.Set(reflect.ValueOf(k))
+		case reflect.String:
+			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 md.badtype("slice", data)
+	}
+	if l := datav.Len(); l != rv.Len() {
+		return md.e("expected array length %d; got TOML array of length %d", rv.Len(), l)
+	}
+	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 md.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 {
+	l := data.Len()
+	for i := 0; i < l; i++ {
+		err := md.unify(data.Index(i).Interface(), indirect(rv.Index(i)))
+		if err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func (md *MetaData) unifyString(data interface{}, rv reflect.Value) error {
+	_, ok := rv.Interface().(json.Number)
+	if ok {
+		if i, ok := data.(int64); ok {
+			rv.SetString(strconv.FormatInt(i, 10))
+		} else if f, ok := data.(float64); ok {
+			rv.SetString(strconv.FormatFloat(f, 'f', -1, 64))
+		} else {
+			return md.badtype("string", data)
+		}
+		return nil
+	}
+
+	if s, ok := data.(string); ok {
+		rv.SetString(s)
+		return nil
+	}
+	return md.badtype("string", data)
+}
+
+func (md *MetaData) unifyFloat64(data interface{}, rv reflect.Value) error {
+	rvk := rv.Kind()
+
+	if num, ok := data.(float64); ok {
+		switch rvk {
+		case reflect.Float32:
+			if num < -math.MaxFloat32 || num > math.MaxFloat32 {
+				return md.parseErr(errParseRange{i: num, size: rvk.String()})
+			}
+			fallthrough
+		case reflect.Float64:
+			rv.SetFloat(num)
+		default:
+			panic("bug")
+		}
+		return nil
+	}
+
+	if num, ok := data.(int64); ok {
+		if (rvk == reflect.Float32 && (num < -maxSafeFloat32Int || num > maxSafeFloat32Int)) ||
+			(rvk == reflect.Float64 && (num < -maxSafeFloat64Int || num > maxSafeFloat64Int)) {
+			return md.parseErr(errParseRange{i: num, size: rvk.String()})
+		}
+		rv.SetFloat(float64(num))
+		return nil
+	}
+
+	return md.badtype("float", data)
+}
+
+func (md *MetaData) unifyInt(data interface{}, rv reflect.Value) error {
+	_, ok := rv.Interface().(time.Duration)
+	if ok {
+		// Parse as string duration, and fall back to regular integer parsing
+		// (as nanosecond) if this is not a string.
+		if s, ok := data.(string); ok {
+			dur, err := time.ParseDuration(s)
+			if err != nil {
+				return md.parseErr(errParseDuration{s})
+			}
+			rv.SetInt(int64(dur))
+			return nil
+		}
+	}
+
+	num, ok := data.(int64)
+	if !ok {
+		return md.badtype("integer", data)
+	}
+
+	rvk := rv.Kind()
+	switch {
+	case rvk >= reflect.Int && rvk <= reflect.Int64:
+		if (rvk == reflect.Int8 && (num < math.MinInt8 || num > math.MaxInt8)) ||
+			(rvk == reflect.Int16 && (num < math.MinInt16 || num > math.MaxInt16)) ||
+			(rvk == reflect.Int32 && (num < math.MinInt32 || num > math.MaxInt32)) {
+			return md.parseErr(errParseRange{i: num, size: rvk.String()})
+		}
+		rv.SetInt(num)
+	case rvk >= reflect.Uint && rvk <= reflect.Uint64:
+		unum := uint64(num)
+		if rvk == reflect.Uint8 && (num < 0 || unum > math.MaxUint8) ||
+			rvk == reflect.Uint16 && (num < 0 || unum > math.MaxUint16) ||
+			rvk == reflect.Uint32 && (num < 0 || unum > math.MaxUint32) {
+			return md.parseErr(errParseRange{i: num, size: rvk.String()})
+		}
+		rv.SetUint(unum)
+	default:
+		panic("unreachable")
+	}
+	return nil
+}
+
+func (md *MetaData) unifyBool(data interface{}, rv reflect.Value) error {
+	if b, ok := data.(bool); ok {
+		rv.SetBool(b)
+		return nil
+	}
+	return md.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 encoding.TextUnmarshaler) error {
+	var s string
+	switch sdata := data.(type) {
+	case Marshaler:
+		text, err := sdata.MarshalTOML()
+		if err != nil {
+			return err
+		}
+		s = string(text)
+	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 md.badtype("primitive (string-like)", data)
+	}
+	if err := v.UnmarshalText([]byte(s)); err != nil {
+		return err
+	}
+	return nil
+}
+
+func (md *MetaData) badtype(dst string, data interface{}) error {
+	return md.e("incompatible types: TOML value has type %T; destination has type %s", data, dst)
+}
+
+func (md *MetaData) parseErr(err error) error {
+	k := md.context.String()
+	return ParseError{
+		LastKey:  k,
+		Position: md.keyInfo[k].pos,
+		Line:     md.keyInfo[k].pos.Line,
+		err:      err,
+		input:    string(md.data),
+	}
+}
+
+func (md *MetaData) e(format string, args ...interface{}) error {
+	f := "toml: "
+	if len(md.context) > 0 {
+		f = fmt.Sprintf("toml: (last key %q): ", md.context)
+		p := md.keyInfo[md.context.String()].pos
+		if p.Line > 0 {
+			f = fmt.Sprintf("toml: line %d (last key %q): ", p.Line, md.context)
+		}
+	}
+	return fmt.Errorf(f+format, args...)
+}
+
+// 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.CanSet() {
+			pv := v.Addr()
+			pvi := pv.Interface()
+			if _, ok := pvi.(encoding.TextUnmarshaler); ok {
+				return pv
+			}
+			if _, ok := pvi.(Unmarshaler); 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
+	}
+	rvi := rv.Interface()
+	if _, ok := rvi.(encoding.TextUnmarshaler); ok {
+		return true
+	}
+	if _, ok := rvi.(Unmarshaler); ok {
+		return true
+	}
+	return false
+}