The Indiana school of macrology in the early 1980s. Eugene, Bruce, and I used this to teach macros to undergrads but Dan Friedman may have implicitly formulated them before Eugene sketched them out and Bruce and I wrote them down.
On Jan 9, 2014, at 1:45 AM, Ben Duan wrote: > What is the source of "three canonical categories"? > > Thanks, > Ben > > > On Sat, Nov 23, 2013 at 2:46 PM, John Clements <cleme...@brinckerhoff.org> > wrote: > I'm preparing a 10-minute lightning talk on hygienic macros in rust (preview: > I'm barely going to *mention* hygiene), and in the process, I've been > surveying some of the Rust macros, and roughly categorizing them in terms of > the "three canonical categories" that Matthias described--apologies if I'm > misrepresenting him/you: > - changing evaluation order, > - implementing a data sublanguage, and > - creating new binding forms. > > Some of the Rust macros seem to fall into a fourth category, which arises > from the fact that certain things are not expressions: > > - abstracting over things that are not expressions. > > For instance: > > cmp_impl!(impl Eq, eq, ne) > cmp_impl!(impl TotalEq, equals) > cmp_impl!(impl Ord, lt, gt, le, ge) > cmp_impl!(impl TotalOrd, cmp -> cmp::Ordering) > > Each of these expands into a top-level "impl" declaration, extending > implementations of, e.g., Ord, from type T to type Ratio<T>. > > More generally, it seems to me that every time you constrain first-class-ness > by making things not-first-class (e.g. module-level stuff in Racket), you > will be required to use macros to abstract over these things. > > Thoughts? > > Back to writing my talk... > > John > > > ____________________ > Racket Users list: > http://lists.racket-lang.org/users > > ____________________ > Racket Users list: > http://lists.racket-lang.org/users
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