Add starlark reader implementation

internal/convert/convert.go

@@ -0,0 +1,87 @@
+package convert
+
+import (
+	"errors"
+	"fmt"
+	"reflect"
+
+	"go.starlark.net/starlark"
+)
+
+var ErrInvalidType = errors.New("unknown type")
+
+func Convert(v any) (starlark.Value, error) {
+	if v == nil {
+		return starlark.None, nil
+	}
+	val := reflect.ValueOf(v)
+	kind := val.Kind()
+	for kind == reflect.Pointer || kind == reflect.Interface {
+		val = val.Elem()
+	}
+	return convert(val)
+}
+
+func convert(val reflect.Value) (starlark.Value, error) {
+	switch val.Kind() {
+	case reflect.Interface:
+		return convert(val.Elem())
+	case reflect.Int, reflect.Int64, reflect.Int32, reflect.Int16, reflect.Int8:
+		return starlark.MakeInt64(val.Int()), nil
+	case reflect.Uint, reflect.Uint64, reflect.Uint32, reflect.Uint16, reflect.Uint8:
+		return starlark.MakeUint64(val.Uint()), nil
+	case reflect.Float64, reflect.Float32:
+		return starlark.Float(val.Float()), nil
+	case reflect.Bool:
+		return starlark.Bool(val.Bool()), nil
+	case reflect.String:
+		return starlark.String(val.String()), nil
+	case reflect.Slice, reflect.Array:
+		return convertSlice(val)
+	case reflect.Map:
+		return convertMap(val)
+	default:
+		return nil, fmt.Errorf("%w: %s", ErrInvalidType, val.Type())
+	}
+}
+
+func convertSlice(val reflect.Value) (starlark.Value, error) {
+	// Detect byte slice
+	if val.Type().Elem().Kind() == reflect.Uint8 {
+		return starlark.Bytes(val.Bytes()), nil
+	}
+
+	elems := make([]starlark.Value, val.Len())
+
+	for i := 0; i < val.Len(); i++ {
+		elem, err := convert(val.Index(i))
+		if err != nil {
+			return nil, err
+		}
+		elems[i] = elem
+	}
+
+	return starlark.NewList(elems), nil
+}
+
+func convertMap(val reflect.Value) (starlark.Value, error) {
+	dict := starlark.NewDict(val.Len())
+	iter := val.MapRange()
+	for iter.Next() {
+		k, err := convert(iter.Key())
+		if err != nil {
+			return nil, err
+		}
+
+		v, err := convert(iter.Value())
+		if err != nil {
+			return nil, err
+		}
+
+		err = dict.SetKey(k, v)
+		if err != nil {
+			return nil, err
+		}
+	}
+	return dict, nil
+}