Implementing Gradual Type In Racket Programming

Gradual typing is a system that makes an excellent integration between static and dynamic typing. Gradual typing allows programmers to mix static and dynamic checking in a program and provides a convenient way to control this checking by adding or removing type annotations on variables. Many programmers choose dynamic languages for creating software. But for some software engineering tasks, having reliable type information is an advantage. In this situation, gradual typing implies a great importance.In this paper, a new way of implementing Gradual type has been discussed. Racket programming language is used for this implementation. Racket is kind of a language,that especially supports both dynamic (Un-typed Racket) and static (Typed Racket)typing. It uses DrRacket compiler to compile the program. Racket has an existing technique of gradual type. But the existing technique has several problems. The main problem was; it can't be debugged or tested because it needs to contain a Racket program without its header line. That means it already has an error because compiler can't identify the file.In this research, a new Racket library has been developed that solves the problem and implement gradual type system with more feasible way. With the help of this library,it is possible to convert Typed Racket (TR) program into Un-typed Racket (UTR)program without removing its header line. Therefore, testing and debugging the programs will not be a problem anymore. Moreover, some other lackings that existing technique also have, completely remove by the improved technique. In addition, this paper tries to show, improved technique of gradual type can be used in standard gradual typed projects that have commercial value by evaluating with more complex programs.It also tries to manifest the improved technique is better, faster and more reasonable than the existing gradual type system by doing the comparison with the existing technique.