Syntactic Closures

_Syntactic Closures_
_syntactic-closures_

This collection provides one file:

 _syntactic-closures.ss_: code from the Bawden-Rees 88 AI memo

This is an exact transcription of the code from the appendix in the
1988 MIT AI memo 1049:

http://library.readscheme.org/servlets/cite.ss?pattern=Rees-AIM-Baw-88

I have made the minimal changes necessary to make the code run in
mzscheme.

======================================================================

TYPES ----------------------------------------------------------------

> sexp = <S-expression>
> expr = <compiled S-expression>
> syntactic-closure = vector ['syntactic-closure, syntactic-env -> expr]
> syntactic-env = syntactic-env * sexp -> expr
> expander = syntactic-env * sexp -> expr
> macrology = syntactic-env -> syntactic-env

EXPORTS --------------------------------------------------------------

> extend-syntactic-environment :: syntactic-env * symbol * expander -> syntactic-env
> make-syntactic-closure :: syntactic-env * (listof symbol) * sexp -> syntactic-closure
> core-syntactic-environment :: syntactic-env
> scheme-macrology :: macrology
> scheme-syntactic-environment :: syntactic-env
> compile :: syntactic-env * sexp -> expr
> execute :: expr -> any