NeoIDL: A Domain Specific Language for Specifying REST Contracts Detailed Design and Extended Evaluation

Service-oriented computing has emerged as an effective approach for integrating business (and systems) that might spread throughout different organizations. A service is a unit of logic modularization that hides implementation details using well-defined contracts. However, existing languages for contract specification in this domain present several limitations. For instance, both WSDL and Swagger use language-independent data formats (XML and JSON) that are not suitable for specifying contracts and often lead to heavyweight specifications. Interface description languages, such as CORBA IDL and Apache Thrift, solve this issue by providing specific languages for contract specifications. Nevertheless, these languages do not target to the REST architectural style and lack support for language extensibility. In this paper we present the design and implementation of NeoIDL, an extensible domain specific language and program generator for writing REST based contracts that are further translated into service’s implementations. In addition, we also present a systematic evaluation of our approach from different perspectives, which involved the implementation of different services using NeoIDL from the domain of Command & Control. In particular, we found initial evidences that shows that NeoIDL can contribute: (i) to bring return on investment with respect to the design and development of NeoIDL, after the implementation of 4 to 7 services; and (ii) to reduce significantly the number of lines of specification when compared to an existing service specification language such as Swagger.