goparsify/json/json.go
2017-08-06 19:15:07 +10:00

69 lines
1.2 KiB
Go

package json
import (
"errors"
. "github.com/vektah/goparsify"
)
var (
value Parser
array = Map(And(WS, "[", Kleene(&value, And(WS, ",")), "]"), func(n Node) Node {
return n.([]Node)[1].([]Node)
})
properties = Kleene(And(WS, String('"'), WS, ":", WS, &value), ",")
object = Map(And(WS, "{", WS, properties, WS, "}"), func(n Node) Node {
ret := map[string]interface{}{}
for _, prop := range n.([]Node)[1].([]Node) {
vals := prop.([]Node)
if len(vals) == 3 {
ret[vals[0].(string)] = vals[2]
} else {
ret[vals[0].(string)] = nil
}
}
return ret
})
_null = Map(And(WS, "null"), func(n Node) Node {
return nil
})
_true = Map(And(WS, "true"), func(n Node) Node {
return true
})
_false = Map(And(WS, "false"), func(n Node) Node {
return false
})
Y = Map(And(&value, WS), func(n Node) Node {
nodes := n.([]Node)
if len(nodes) > 0 {
return nodes[0]
}
return nil
})
)
func init() {
value = Any(_null, _true, _false, String('"'), array, object)
}
func Unmarshal(input string) (interface{}, error) {
result, remaining, err := ParseString(Y, input)
if err != nil {
return result, err
}
if remaining != "" {
return result, errors.New("left unparsed: " + remaining)
}
return result, err
}