Recently my favorite Scheme implementation, LispMe for PalmOS, got a new major release - it now supports compile-time definition of new datatypes. As a result, I'm planning a "file" datatype and a set of new functions for accessing files on the flash memory storage cards available on certain PalmOS models. So, I have two questions:
1: Is there a good set of standardized semantics for file access in Scheme? I want the library to support access of binary data as well as text, and to support other relevant operations: directory listing, creating/deleting files and directories, etc. I was thinking of emulating parts of the POSIX library from Guile, but that part of the documentation seems to be missing. 2: I would like to somehow support mechanisms for allowing Scheme code to be notified when cards are ejected or inserted, but I haven't thought of a good way to do it. In C, the notifications are provided by a re-entrant call to the application's main routine. I'm not quite sure how a notification like that should be implemented for a Scheme VM, however - I suppose Scheme code could poll to see if any such notifications have been enqueued, or block waiting for such an event, or maybe even use something like a call/cc to enter a filesystem-critical-region, where the continuation would be called if a card event happened (in C++, this would be equivalent to an exception being thrown by the filesystem library)
>>>>> "GEC" == George Caswell <tetsu...@maine.rr.com> writes:
GEC> Hi,
GEC> Recently my favorite Scheme implementation, LispMe for PalmOS, got a new GEC> major release - it now supports compile-time definition of new datatypes. As GEC> a result, I'm planning a "file" datatype and a set of new functions for GEC> accessing files on the flash memory storage cards available on certain PalmOS GEC> models. So, I have two questions:
GEC> 1: Is there a good set of standardized semantics for file access in Scheme? GEC> I want the library to support access of binary data as well as text, and to GEC> support other relevant operations: directory listing, creating/deleting files GEC> and directories, etc. I was thinking of emulating parts of the POSIX library GEC> from Guile, but that part of the documentation seems to be missing.
I recommend a look at the POSIX subsystem in Scheme 48 or that in scsh. Both are well-documented.
-- Cheers =8-} Mike Friede, Völkerverständigung und überhaupt blabla
