On Mon, Sep 6, 2010 at 9:12 PM, Ludovic Courtès <l...@gnu.org> wrote: > > Well, since there are only 9 of them, they could probably be implemented > as special cases, with an augmented ‘match-gen-ellipses’, which would be > told the minimum number of elements expected?
Oh, the Wright syntax limited you to 9 forms, so "..10" is illegal? Then this could be done in pure syntax-rules. >> Do you have any code which actually uses the ..k >> patterns? :) > > I do! :-) > > http://git.sv.gnu.org/cgit/guile-rpc.git/tree/modules/rpc/compiler.scm#n312 > > Well it uses only ‘..1’. The same code would work with ‘..1’ replaced > by ‘...’, but then errors in the input wouldn’t be detected as nicely. "..1" is actually useful - it's the analog of "+" in regular expressions, and allows simplifying many syntax-rules patterns you see written (elt0 elt1 ...) as (elt ..1). If the elements are more complex patterns this is a big win. -- Alex
