Hi, Mark H Weaver <m...@netris.org> skribis:
> I recently tried to implement reader directives, e.g.: > > #!fold-case (from R7RS) > #!no-fold-case (from R7RS) > #!curly-infix (from SRFI-105) > > However, I ran into a rather serious problem. Guile's reader options > are global to the entire process, but clearly these reader directives > should affect only the port they are read from. So we need to support > per-port reader options. I think we should instead be able to instantiate new readers–i.e., have a higher-order ‘make-reader’ procedure (that’s how Guile-Reader started, actually.) That, combined with the ‘current-reader’ fluid, should provide good flexibility. As an example, http://git.savannah.gnu.org/cgit/guile-reader.git/tree/modules/system/reader/confinement.scm provides reader settings that are confined for each module. Also, I think ports should remain reader-oblivious. ‘read’ is fundamentally at a higher level of abstraction, so I’d personally prefer not to have ports fiddle with it. WDYT? Thanks, Ludo’.
