Racket's macro system only expands forms in expression position by default.
However, certain DSLs within Racket, notably
match, provide
hooks for defining macros that are expanded in DSL-specific contexts.
In the case of match, one may define
match expanders
which allow abstraction over match patterns.
This package provides a form define-auxiliary-macro-context, with an
implementation based on that of match expanders, which allows
convenient definition of new kinds of macro expansion contexts. In
principle, match expanders could be defined in terms of
define-auxiliary-macro-context.
Potential uses include:
-
defining one's own pattern language, complete with match-expander style macros for extending the pattern syntax
-
defining a new kind of
lambda, whose binding specification form is extensible
Toy/testing examples of the use of define-auxiliary-macro-context
can be found in
auxiliary-macro-context/test/.
A real-world example can be found in the implementation of the pattern-language over assertions in Syndicate.
Install via the package catalog,
raco pkg install auxiliary-macro-context
Alternatively, check out the repository and, in the directory
containing Makefile,
make link
or
raco pkg install --link -n auxiliary-macro-context `pwd`
Copyright © 2016, 2022 Tony Garnock-Jones mailto:tonyg@leastfixedpoint.com
This program is free software: you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.
This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public License along with this program (see the files "lgpl.txt" and "gpl.txt"). If not, see http://www.gnu.org/licenses/.