Function IsCompatible

codegen/transformer.go:120–153

IsCompatible returns an error if a and b are not both objects, both arrays, both maps, both unions or one union and one object. actx and bctx are used to build the error message if any.

(a, b expr.DataType, actx, bctx string)

// both maps, both unions or one union and one object.  actx and bctx are used
// to build the error message if any.
func IsCompatible(a, b expr.DataType, actx, bctx string) error {
	switch {
	case expr.IsObject(a):
		if !expr.IsObject(b) && !expr.IsUnion(b) {
			return fmt.Errorf("%s is an object but %s type is %s", actx, bctx, b.Name())
		}
	case expr.IsArray(a):
		if !expr.IsArray(b) {
			return fmt.Errorf("%s is an array but %s type is %s", actx, bctx, b.Name())
		}
	case expr.IsMap(a):
		if !expr.IsMap(b) {
			return fmt.Errorf("%s is a hash but %s type is %s", actx, bctx, b.Name())
		}
	case expr.IsUnion(a):
		if !expr.IsUnion(b) && !expr.IsObject(b) {
			return fmt.Errorf("%s is a union but %s type is %s", actx, bctx, b.Name())
		}
	default:
		aUT, isAUT := a.(expr.UserType)
		bUT, isBUT := b.(expr.UserType)
		switch {
		case isAUT && isBUT:
			return IsCompatible(aUT.Attribute().Type, bUT.Attribute().Type, actx, bctx)
		case isAUT:
			return IsCompatible(aUT.Attribute().Type, b, actx, bctx)
		case isBUT:
			return IsCompatible(a, bUT.Attribute().Type, actx, bctx)
		case a.Kind() != b.Kind():
			return fmt.Errorf("%s is a %s but %s type is %s", actx, a.Name(), bctx, b.Name())
		}
	}
	return nil
}

// AppendHelpers takes care of only appending helper functions from newH that
// are not already in oldH.