package toml
import (
"bytes"
"fmt"
"io"
"math"
"reflect"
"sort"
"strconv"
"strings"
"time"
)
// encodes a string to a TOML-compliant string value
func encodeTomlString(value string) string {
var b bytes.Buffer
for _, rr := range value {
switch rr {
case '\b':
b.WriteString(`\b`)
case '\t':
b.WriteString(`\t`)
case '\n':
b.WriteString(`\n`)
case '\f':
b.WriteString(`\f`)
case '\r':
b.WriteString(`\r`)
case '"':
b.WriteString(`\"`)
case '\\':
b.WriteString(`\\`)
default:
intRr := uint16(rr)
if intRr < 0x001F {
b.WriteString(fmt.Sprintf("\\u%0.4X", intRr))
} else {
b.WriteRune(rr)
}
}
}
return b.String()
}
func tomlValueStringRepresentation(v interface{}, indent string, arraysOneElementPerLine bool) (string, error) {
switch value := v.(type) {
case uint64:
return strconv.FormatUint(value, 10), nil
case int64:
return strconv.FormatInt(value, 10), nil
case float64:
// Ensure a round float does contain a decimal point. Otherwise feeding
// the output back to the parser would convert to an integer.
if math.Trunc(value) == value {
return strings.ToLower(strconv.FormatFloat(value, 'f', 1, 32)), nil
}
return strings.ToLower(strconv.FormatFloat(value, 'f', -1, 32)), nil
case string:
return "\"" + encodeTomlString(value) + "\"", nil
case []byte:
b, _ := v.([]byte)
return tomlValueStringRepresentation(string(b), indent, arraysOneElementPerLine)
case bool:
if value {
return "true", nil
}
return "false", nil
case time.Time:
return value.Format(time.RFC3339), nil
case nil:
return "", nil
}
rv := reflect.ValueOf(v)
if rv.Kind() == reflect.Slice {
var values []string
for i := 0; i < rv.Len(); i++ {
item := rv.Index(i).Interface()
itemRepr, err := tomlValueStringRepresentation(item, indent, arraysOneElementPerLine)
if err != nil {
return "", err
}
values = append(values, itemRepr)
}
if arraysOneElementPerLine && len(values) > 1 {
stringBuffer := bytes.Buffer{}
valueIndent := indent + ` ` // TODO: move that to a shared encoder state
stringBuffer.WriteString("[\n")
for _, value := range values {
stringBuffer.WriteString(valueIndent)
stringBuffer.WriteString(value)
stringBuffer.WriteString(`,`)
stringBuffer.WriteString("\n")
}
stringBuffer.WriteString(indent + "]")
return stringBuffer.String(), nil
}
return "[" + strings.Join(values, ",") + "]", nil
}
return "", fmt.Errorf("unsupported value type %T: %v", v, v)
}
func (t *Tree) writeTo(w io.Writer, indent, keyspace string, bytesCount int64, arraysOneElementPerLine bool) (int64, error) {
simpleValuesKeys := make([]string, 0)
complexValuesKeys := make([]string, 0)
for k := range t.values {
v := t.values[k]
switch v.(type) {
case *Tree, []*Tree:
complexValuesKeys = append(complexValuesKeys, k)
default:
simpleValuesKeys = append(simpleValuesKeys, k)
}
}
sort.Strings(simpleValuesKeys)
sort.Strings(complexValuesKeys)
for _, k := range simpleValuesKeys {
v, ok := t.values[k].(*tomlValue)
if !ok {
return bytesCount, fmt.Errorf("invalid value type at %s: %T", k, t.values[k])
}
repr, err := tomlValueStringRepresentation(v.value, indent, arraysOneElementPerLine)
if err != nil {
return bytesCount, err
}
if v.comment != "" {
comment := strings.Replace(v.comment, "\n", "\n"+indent+"#", -1)
start := "# "
if strings.HasPrefix(comment, "#") {
start = ""
}
writtenBytesCountComment, errc := writeStrings(w, "\n", indent, start, comment, "\n")
bytesCount += int64(writtenBytesCountComment)
if errc != nil {
return bytesCount, errc
}
}
var commented string
if v.commented {
commented = "# "
}
writtenBytesCount, err := writeStrings(w, indent, commented, k, " = ", repr, "\n")
bytesCount += int64(writtenBytesCount)
if err != nil {
return bytesCount, err
}
}
for _, k := range complexValuesKeys {
v := t.values[k]
combinedKey := k
if keyspace != "" {
combinedKey = keyspace + "." + combinedKey
}
var commented string
if t.commented {
commented = "# "
}
switch node := v.(type) {
// node has to be of those two types given how keys are sorted above
case *Tree:
tv, ok := t.values[k].(*Tree)
if !ok {
return bytesCount, fmt.Errorf("invalid value type at %s: %T", k, t.values[k])
}
if tv.comment != "" {
comment := strings.Replace(tv.comment, "\n", "\n"+indent+"#", -1)
start := "# "
if strings.HasPrefix(comment, "#") {
start = ""
}
writtenBytesCountComment, errc := writeStrings(w, "\n", indent, start, comment)
bytesCount += int64(writtenBytesCountComment)
if errc != nil {
return bytesCount, errc
}
}
writtenBytesCount, err := writeStrings(w, "\n", indent, commented, "[", combinedKey, "]\n")
bytesCount += int64(writtenBytesCount)
if err != nil {
return bytesCount, err
}
bytesCount, err = node.writeTo(w, indent+" ", combinedKey, bytesCount, arraysOneElementPerLine)
if err != nil {
return bytesCount, err
}
case []*Tree:
for _, subTree := range node {
writtenBytesCount, err := writeStrings(w, "\n", indent, commented, "[[", combinedKey, "]]\n")
bytesCount += int64(writtenBytesCount)
if err != nil {
return bytesCount, err
}
bytesCount, err = subTree.writeTo(w, indent+" ", combinedKey, bytesCount, arraysOneElementPerLine)
if err != nil {
return bytesCount, err
}
}
}
}
return bytesCount, nil
}
func writeStrings(w io.Writer, s ...string) (int, error) {
var n int
for i := range s {
b, err := io.WriteString(w, s[i])
n += b
if err != nil {
return n, err
}
}
return n, nil
}
// WriteTo encode the Tree as Toml and writes it to the writer w.
// Returns the number of bytes written in case of success, or an error if anything happened.
func (t *Tree) WriteTo(w io.Writer) (int64, error) {
return t.writeTo(w, "", "", 0, false)
}
// ToTomlString generates a human-readable representation of the current tree.
// Output spans multiple lines, and is suitable for ingest by a TOML parser.
// If the conversion cannot be performed, ToString returns a non-nil error.
func (t *Tree) ToTomlString() (string, error) {
var buf bytes.Buffer
_, err := t.WriteTo(&buf)
if err != nil {
return "", err
}
return buf.String(), nil
}
// String generates a human-readable representation of the current tree.
// Alias of ToString. Present to implement the fmt.Stringer interface.
func (t *Tree) String() string {
result, _ := t.ToTomlString()
return result
}
// ToMap recursively generates a representation of the tree using Go built-in structures.
// The following types are used:
//
// * bool
// * float64
// * int64
// * string
// * uint64
// * time.Time
// * map[string]interface{} (where interface{} is any of this list)
// * []interface{} (where interface{} is any of this list)
func (t *Tree) ToMap() map[string]interface{} {
result := map[string]interface{}{}
for k, v := range t.values {
switch node := v.(type) {
case []*Tree:
var array []interface{}
for _, item := range node {
array = append(array, item.ToMap())
}
result[k] = array
case *Tree:
result[k] = node.ToMap()
case *tomlValue:
result[k] = node.value
}
}
return result
}