Locales


\begin{inset}{{\bf T3}:} We are working on a module system which will eventually subsume the functionality of {\mbox {\tt locale}}. \end{inset}

Locales serve two purposes. First, they provide an incremental or declarative syntax for creating variable bindings in a contour. Second, they provide access to environments as objects which can be dynamically manipulated. The term locale is used to mean both the kind of contour introduced by a LOCALE-expression, and the object which represents the environment.

There are no global variables in T; all variables are lexically bound in some contour. Locales play the role of what is known in other Lisp and Scheme dialects as the global environment.

Special form


\begin{inset}{} {\tt DEFINE} creates a binding for {\it variable\/} in the lexic... ...uiv$\ & (DEFINE F (LAMBDA X (LIST X 2))) \end{tabular} \end{codexenv}\end{inset}

Special form


\begin{inset}{} \par The value of the {\mbox {\tt LSET}} special form is undefin... ...ables bound by {\tt LSET} may be. See {\tt SET}, page \pageref{SET}. \end{inset}


\begin{inset}{} \par Creates a locale inferior to {\it superior-locale\/}. {\it ... ...EFINE *FOO-ENV* (MAKE-LOCALE STANDARD-ENV '*FOO-ENV*)) \end{codexenv}\end{inset}


\begin{inset}{} Creates a locale containing no bindings whatsoever. \end{inset}

Type predicate


\begin{inset}{} Returns true if {\it object\/} is a locale. \end{inset}