Support for ir-macro-transformer

[arthurmaciel]

I still can't propose a pull request, but if anyone else could that would be awesome.

CHICKEN's docs and implementation.

[justinethier]

Some considerations:

https://github.com/ashinn/chibi-scheme/issues/114 https://gist.github.com/baguette/2632464

Unfortunately it seems the preferred way to implement these is in terms of syntactic closures (which we do not currently support) rather than explicit renaming macros.

[arthurmaciel]

@justinethier, while we do not provide syntatic closures (if we ever will), do you think it is useful to provide the ir-macro as a package? I can arrange that if you think so.

[justinethier]

@arthurmaciel Perhaps, but there is not a way to directly use another macro system provided by a package. I think it will be necessary to modify Cyclone to recognize these macros. The macro for ir-macros would also need to be written in terms of er macros.