https://github.com/tonyg/racket-auxiliary-macro-context

Syntactic extensibility outside expressions.
https://github.com/tonyg/racket-auxiliary-macro-context

macros match-expanders racket

Last synced: 5 days ago
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Syntactic extensibility outside expressions.

• Host: GitHub
• URL: https://github.com/tonyg/racket-auxiliary-macro-context
• Owner: tonyg
• License: other
• Created: 2016-07-23T18:07:07.000Z (over 8 years ago)
• Default Branch: master
• Last Pushed: 2022-12-14T21:54:33.000Z (about 2 years ago)
• Last Synced: 2024-12-03T08:07:42.603Z (2 months ago)
• Topics: macros, match-expanders, racket
• Language: Racket
• Size: 18.6 KB
• Stars: 6
• Watchers: 3
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • License: COPYING

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README

        
# Syntactic extensibility outside expressions

Racket's macro system only expands forms in *expression* position by

default.

However, certain DSLs within Racket, notably

[`match`](http://docs.racket-lang.org/reference/match.html), provide

hooks for defining macros that are expanded in DSL-specific contexts.

In the case of `match`, one may define

[match expanders](http://docs.racket-lang.org/reference/match.html#%28part._.Extending_match%29)

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/`](auxiliary-macro-context/test/).

A real-world example can be found in the implementation of the

pattern-language over assertions in

[Syndicate](https://github.com/tonyg/syndicate/).

# Installation

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`

# Licence

Copyright © 2016, 2022 Tony Garnock-Jones 

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 .