Buy GNU books!
|[ < ]||[ > ]||[ << ]||[ Up ]||[ >> ]||[Top]||[Contents]||[Index]||[ ? ]|
Scheme, as defined in R5RS, does not have a full module system. However it does define the concept of a top-level environment. Such an environment maps identifiers (symbols) to Scheme objects such as procedures and lists: 14.4 The Concept of Closure. In other words, it implements a set of bindings.
Environments in R5RS can be passed as the second argument to
eval (see section 28.3 Procedures for On the Fly Evaluation). Three procedures are defined to
interaction-environment (see section 28.3 Procedures for On the Fly Evaluation).
In addition, in Guile any module can be used as an R5RS environment,
i.e., passed as the second argument to
scheme-report-environmentreturns a specifier for an environment that is empty except for all bindings defined in the report that are either required or both optional and supported by the implementation.
null-environmentreturns a specifier for an environment that is empty except for the (syntactic) bindings for all syntactic keywords defined in the report that are either required or both optional and supported by the implementation.
Currently Guile does not support values of version for other revisions of the report.
The effect of assigning (through the use of
eval) a variable
bound in a
scheme-report-environment (for example
is unspecified. Currently the environments specified by
scheme-report-environment are not immutable in Guile.
|webmaster||delorie software privacy|
|Copyright © 2003 by The Free Software Foundation||Updated Jun 2003|