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Re: Do we NEED a marker at all?

This page is part of the web mail archives of SRFI 105 from before July 7th, 2015. The new archives for SRFI 105 contain all messages, not just those from before July 7th, 2015.

2012/9/5 David A. Wheeler <dwheeler@xxxxxxxxxxxx>:
> John Cowan:
>> http://trac.sacrideo.us/wg/wiki/BracketsBraces shows the meaning
>> of square brackets and curly braces in my Scheme test suite, which
>> currently includes 45 implementations.  Only Chibi and RScheme currently
>> do something special with braces; the other implementations treat them
>> as either synonyms for parentheses, lexical syntax errors, or identifier
>> characters.

In Racket read-syntax will store the type of parenthesis used in the
syntax object.
This implies that macros can use this information during expansion.



Combining this with #%app one can make (foo bar) mean one thing and {foo bar}
mean another thing without messing with the reader.

A random example of this:

But search the Racket mailing list archive for other examples.

/Jens Axel