The Nanocheme Language

The behavior of each nano-agent is programmed using a user-friendly language, called

nanoScheme, based on the Scheme programming language. It includes a reduced set of

primitives which is a subset of the R4RS specification (Clinger & Rees 1991). This subset

includes the following functions:

 Basic calculus:+ - * / = < > <= >=

 Mathematics:cos sin acos asin log expt round

 Predicates:number? integer? even? string? symbol? string=? eqv?

pair? null? procedure?

 Strings and symbols:string->number number->string string->symbol

symbol->string substring string-length string-append

 List processing:cons car cdr set-car! set-cdr!

 Control and evaluation:quote eval apply load define lambda set! begin if

Most of the missing features of the Scheme specification could be added by programming

them directly in nanoScheme. This provides the application developer a high-level

interactive language which is embedded in each nano-agent. Here is an example of the

implementation of the R4RS function that returns the length of a list:

( define ( length x )

( if ( null? x ) 0

( + 1 ( length ( cdr x ) ) ) ) )