The SRFI-10 structure defines an octothorpe reader syntax, comma, as specified
in SRFI 10. It also defines a procedure, DEFINE-READER-CONSTRUCTOR, for user-
defined reader constructors.
(DEFINE-READER-CONSTRUCTOR <symbol> <procedure>) -> unspecific ;procedure
Define SYMBOL to be a reader constructor, calling PROCEDURE at read-time;
that is, for any instances of #,(SYMBOL <arg> ...), PROCEDURE will be applied
to the arguments ARG ....
The test/ directory contains a couple of examples. A structure whose name is
of the form SRFI-10-TEST/<foo> corresponds to test/<foo>.scm.
This implementation of SRFI 10 is not perfect: it will give errors regarding
invalid data in quotations if your reader constructors construct anything that
isn't an S-expression, and all that's only if you quote those; if you don't
quote the things, you'll get even worse errors.
There is one built-in reader constructor:
#,(DEFINE-READER-CONSTRUCTOR <name> <procedure-expression>) ;reader constructor
Just like the DEFINE-READER-CONSTRUCTOR procedure, except that NAME must be a
literal symbol, and this operates at read-time. PROCEDURE-EXPRESSION will be
evaluated in the what interaction environment is in state during read-time.