ledisdb/vendor/github.com/glendc/gopher-json/util.go

112 lines
2.6 KiB
Go

package json
import (
"encoding/json"
"errors"
"strconv"
"github.com/yuin/gopher-lua"
)
var (
errFunction = errors.New("cannot encode function to JSON")
errChannel = errors.New("cannot encode channel to JSON")
errState = errors.New("cannot encode state to JSON")
errUserData = errors.New("cannot encode userdata to JSON")
errNested = errors.New("cannot encode recursively nested tables to JSON")
)
type jsonValue struct {
lua.LValue
visited map[*lua.LTable]bool
}
func (j jsonValue) MarshalJSON() ([]byte, error) {
return toJSON(j.LValue, j.visited)
}
func toJSON(value lua.LValue, visited map[*lua.LTable]bool) (data []byte, err error) {
switch converted := value.(type) {
case lua.LBool:
data, err = json.Marshal(converted)
case lua.LChannel:
err = errChannel
case lua.LNumber:
data, err = json.Marshal(converted)
case *lua.LFunction:
err = errFunction
case *lua.LNilType:
data, err = json.Marshal(converted)
case *lua.LState:
err = errState
case lua.LString:
data, err = json.Marshal(converted)
case *lua.LTable:
var arr []jsonValue
var obj map[string]jsonValue
if visited[converted] {
panic(errNested)
}
visited[converted] = true
converted.ForEach(func(k lua.LValue, v lua.LValue) {
i, numberKey := k.(lua.LNumber)
if numberKey && obj == nil {
index := int(i) - 1
if index != len(arr) {
// map out of order; convert to map
obj = make(map[string]jsonValue)
for i, value := range arr {
obj[strconv.Itoa(i+1)] = value
}
obj[strconv.Itoa(index+1)] = jsonValue{v, visited}
return
}
arr = append(arr, jsonValue{v, visited})
return
}
if obj == nil {
obj = make(map[string]jsonValue)
for i, value := range arr {
obj[strconv.Itoa(i+1)] = value
}
}
obj[k.String()] = jsonValue{v, visited}
})
if obj != nil {
data, err = json.Marshal(obj)
} else {
data, err = json.Marshal(arr)
}
case *lua.LUserData:
// TODO: call metatable __tostring?
err = errUserData
}
return
}
func fromJSON(L *lua.LState, value interface{}) lua.LValue {
switch converted := value.(type) {
case bool:
return lua.LBool(converted)
case float64:
return lua.LNumber(converted)
case string:
return lua.LString(converted)
case []interface{}:
arr := L.CreateTable(len(converted), 0)
for _, item := range converted {
arr.Append(fromJSON(L, item))
}
return arr
case map[string]interface{}:
tbl := L.CreateTable(0, len(converted))
for key, item := range converted {
tbl.RawSetH(lua.LString(key), fromJSON(L, item))
}
return tbl
}
return lua.LNil
}