Page:Scheme - An interpreter for extended lambda calculus.djvu/3

   one to count the, as follows:

    This is the side effect primitive. It is analogous to the LISP function. For example, to define a cell [Smith and Hewitt], we may use  as follows:

Those of you who may complain about the lack of  are invited to write   instead of.     This is similar to the LISP function. It evaluates its argument, and then evaluates the resulting s-expression as SCHEME code.     This is the "escape operator" which gives the user a handle on the control structure of the interpreter. The expression:

 </dl>