The update of the document is now available on the official site:
Changes are:
- The hygiene mechanism has been simplified. A binding
for an identifier can only capture a reference to another if both
were introduced together in the same SYNTAX or QUASISYNTAX form.
A rationale based on referential transparency is given that this is
the right choice. [This rationale can be made more precise but
is somewhat complicated while not really necessary - I may remove it
in future]
- The section on "hygiene breaking" has been removed, as have statements
promoting use of make-fluid-identifier over datum->syntax-object for
these kinds of macros. Both mechanisms provide legitimate solutions
to the capturing problem, and these are now shown in their respective
specification sections. It is also shown how to implement Chez's
FLUID-LET-SYNTAX in terms of make-fluid-identifier.
- The mechanism for escaping ellipses in syntax-case macros is discussed.
- name changes: SYNTAX-QUOTE --> EMBEDDED-SYNTAX
MAKE-CAPTURING-IDENTIFIER --> MAKE-FLUID-IDENTIFIER
DATUM->SYNTAX --> DATUM->SYNTAX-OBJECT
SYNTAX->DATUM --> SYNTAX-OBJECT->DATUM
Andre