Repel

Is a interactive to a programming language.

It originated with LISP system,but many other languages.

It is used to manage interactive session.

components of repel

1-A read function,which rreads input from the keyboards.

2-An eval function,which code passed to it.

3-A print function,which formats and dispay results.

4-A loop function,which runs the three previous commands until termination.