Abdulaziz Ghuloum
24ece86772
syntax: (stale-when guard-expr e* ...) ;; in definition context
(stale-when guard-expr e e* ...) ;; in expression context
semantics:
When a stale-when form is encountered while expanding any code
(expressions, macros, macros in macros, etc.) in a library
body, the guard-expr is expanded (but not evaluated) and
serialized along with the library. When the library is later
reloaded from fasl and before it is installed, the guard-expr
is evaluated. If guard-expr returns true, the fasl content is
ignored and the library is recompiled afresh from source.
Ikarus Scheme is an implementation of the Scheme programming language. The preliminary release of Ikarus implements the majority of the features found in the current standard, the Revised 6 report on the algorithmic language Scheme including full R6RS library and script syntax, syntax-case, unicode strings, bytevectors, user-defined record types, exception handling, conditions, and enumerations. Over 80% of the R6RS procedures and keywords are currently implemented and subsequent releases will proceed towards brining Ikarus to full R6RS conformance. The main purpose behind releasing Ikarus early is to give Scheme programmers the opportunity to experiment with the various new features that were newly introduced in R6RS. The most important of such features is the ability to structure large programs into libraries; where each library extends the language through procedural and syntactic abstractions. Many useful libraries can be written using the currently supported set of R6RS features including text processing tools, symbolic logic systems, interpreters and compilers, and many mathematical and scientific packages. It is my hope that this release will encourage the Scheme community to write and to share their most useful R6RS libraries.