Function ParseMutation

dql/parser_mutation.go:15–50

ParseMutation parses a block into a mutation. Returns an object with a mutation or an upsert block with mutation, otherwise returns nil with an error.

(mutation string)

// ParseMutation parses a block into a mutation. Returns an object with a mutation or
// an upsert block with mutation, otherwise returns nil with an error.
func ParseMutation(mutation string) (req *api.Request, err error) {
	var lexer lex.Lexer
	lexer.Reset(mutation)
	lexer.Run(lexTopLevel)
	if err := lexer.ValidateResult(); err != nil {
		return nil, err
	}

	it := lexer.NewIterator()
	if !it.Next() {
		return nil, it.Errorf("Invalid mutation")
	}

	item := it.Item()
	switch item.Typ {
	case itemUpsertBlock:
		if req, err = parseUpsertBlock(it); err != nil {
			return nil, err
		}
	case itemLeftCurl:
		mu, err := parseMutationBlock(it)
		if err != nil {
			return nil, err
		}
		req = &api.Request{Mutations: []*api.Mutation{mu}}
	default:
		return nil, it.Errorf("Unexpected token: [%s]", item.Val)
	}

	// mutations must be enclosed in a single block.
	if it.Next() && it.Item().Typ != lex.ItemEOF {
		return nil, it.Errorf("Unexpected %s after the end of the block", it.Item().Val)
	}

	return req, nil
}

// parseUpsertBlock parses the upsert block
func parseUpsertBlock(it *lex.ItemIterator) (*api.Request, error) {