Section 9.20 contains the following two paragraphs:
A template of the form [...]. This allows syntactic abstractions to
expand into forms containing ellipses.
As an example, if let and cond are defined as in [...].
The structure suggests the second paragraph is an example of a macro
expanding into forms containing ellipses, but it is not.
The second paragraph appears in R5RS after discussion of renaming to
prevent inadvertent capture of free identifiers, making it clear what the
example is demonstrating. In its current context it is unclear.
Also, it may be helpful to demonstrate the (<ellipsis> <template>) form if
there is a succinct example. If not, a citation to an extended example
might be appropriate. I know that Krishnamurthi's "Automata via Macros"
JFP paper includes an example of (... ...). I'm sure there are others.
http://www.cs.brown.edu/~sk/Publications/Papers/Published/sk-automata-macros/
David
Received on Tue Jun 26 2007 - 17:00:12 UTC