matterbridge/vendor/github.com/d5/tengo/v2/stdlib/json/encode.go

147 lines
3.0 KiB
Go

// A modified version of Go's JSON implementation.
// Copyright 2010 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package json
import (
"encoding/base64"
"errors"
"math"
"strconv"
"github.com/d5/tengo/v2"
)
// Encode returns the JSON encoding of the object.
func Encode(o tengo.Object) ([]byte, error) {
var b []byte
switch o := o.(type) {
case *tengo.Array:
b = append(b, '[')
len1 := len(o.Value) - 1
for idx, elem := range o.Value {
eb, err := Encode(elem)
if err != nil {
return nil, err
}
b = append(b, eb...)
if idx < len1 {
b = append(b, ',')
}
}
b = append(b, ']')
case *tengo.ImmutableArray:
b = append(b, '[')
len1 := len(o.Value) - 1
for idx, elem := range o.Value {
eb, err := Encode(elem)
if err != nil {
return nil, err
}
b = append(b, eb...)
if idx < len1 {
b = append(b, ',')
}
}
b = append(b, ']')
case *tengo.Map:
b = append(b, '{')
len1 := len(o.Value) - 1
idx := 0
for key, value := range o.Value {
b = strconv.AppendQuote(b, key)
b = append(b, ':')
eb, err := Encode(value)
if err != nil {
return nil, err
}
b = append(b, eb...)
if idx < len1 {
b = append(b, ',')
}
idx++
}
b = append(b, '}')
case *tengo.ImmutableMap:
b = append(b, '{')
len1 := len(o.Value) - 1
idx := 0
for key, value := range o.Value {
b = strconv.AppendQuote(b, key)
b = append(b, ':')
eb, err := Encode(value)
if err != nil {
return nil, err
}
b = append(b, eb...)
if idx < len1 {
b = append(b, ',')
}
idx++
}
b = append(b, '}')
case *tengo.Bool:
if o.IsFalsy() {
b = strconv.AppendBool(b, false)
} else {
b = strconv.AppendBool(b, true)
}
case *tengo.Bytes:
b = append(b, '"')
encodedLen := base64.StdEncoding.EncodedLen(len(o.Value))
dst := make([]byte, encodedLen)
base64.StdEncoding.Encode(dst, o.Value)
b = append(b, dst...)
b = append(b, '"')
case *tengo.Char:
b = strconv.AppendInt(b, int64(o.Value), 10)
case *tengo.Float:
var y []byte
f := o.Value
if math.IsInf(f, 0) || math.IsNaN(f) {
return nil, errors.New("unsupported float value")
}
// Convert as if by ES6 number to string conversion.
// This matches most other JSON generators.
abs := math.Abs(f)
fmt := byte('f')
if abs != 0 {
if abs < 1e-6 || abs >= 1e21 {
fmt = 'e'
}
}
y = strconv.AppendFloat(y, f, fmt, -1, 64)
if fmt == 'e' {
// clean up e-09 to e-9
n := len(y)
if n >= 4 && y[n-4] == 'e' && y[n-3] == '-' && y[n-2] == '0' {
y[n-2] = y[n-1]
y = y[:n-1]
}
}
b = append(b, y...)
case *tengo.Int:
b = strconv.AppendInt(b, o.Value, 10)
case *tengo.String:
b = strconv.AppendQuote(b, o.Value)
case *tengo.Time:
y, err := o.Value.MarshalJSON()
if err != nil {
return nil, err
}
b = append(b, y...)
case *tengo.Undefined:
b = append(b, "null"...)
default:
// unknown type: ignore
}
return b, nil
}