// Find implements the charlatan.Record interface
func (r *JSONRecord) Find(field *ch.Field) (*ch.Const, error) {
var ok bool
var partial *json.RawMessage
var name string
if name = field.Name(); len(name) == 0 {
return nil, errEmptyField
}
// support for "SELECT *"
if name == "*" {
b, err := json.Marshal(r.attrs)
if err != nil {
return nil, err
}
return ch.StringConst(string(b)), nil
}
attrs := r.attrs
parts := strings.Split(name, ".")
for i, k := range parts {
partial, ok = attrs[k]
if !ok {
if r.SoftMatching {
return ch.NullConst(), nil
}
return nil, fmt.Errorf("Unknown '%s' field (in '%s')", k, field.Name())
}
// update the attrs if we need to go deeper
if i < len(parts)-1 {
attrs = make(map[string]*json.RawMessage)
if err := json.Unmarshal(*partial, &attrs); err != nil {
if r.SoftMatching {
return ch.NullConst(), nil
}
return nil, err
}
}
}
return jsonToConst(partial)
}
// AtIndex gets the value at the given index
func (r *CSVRecord) AtIndex(index int) (*ch.Const, error) {
if index < 0 || index > len(r.record) {
return nil, fmt.Errorf("index out of bounds %d", index)
}
// FIXME should we accept NULL values?
value := r.record[index]
if value == "NULL" {
return ch.NullConst(), nil
}
return ch.ConstFromString(value), nil
}
func jsonToConst(partial *json.RawMessage) (*ch.Const, error) {
var value string
if partial == nil {
return ch.NullConst(), nil
}
asString := string(*partial)
if asString == "null" {
return ch.NullConst(), nil
}
if err := json.Unmarshal(*partial, &value); err != nil {
if err, ok := err.(*json.UnmarshalTypeError); ok {
// we failed to unmarshal into a string, let's try the other types
switch err.Value {
case "number":
var n json.Number
if err := json.Unmarshal(*partial, &n); err != nil {
return nil, err
}
value = n.String()
case "bool":
value = asString
default:
return nil, err
}
}
}
return ch.ConstFromString(value), nil
}