[plt-scheme] dots

From: Robert Nikander (nikander at nc.rr.com)
Date: Sun Jun 10 14:10:23 EDT 2007

On Jun 10, 2007, at 1:27 PM, Jos Koot wrote:
> Yes, I thought of using a readertable too, but did not succeed, not  
> even with another character for the dot. How do you put "(dot " in  
> font of the a of a.b when the readertable-procedure for the period  
> is invoked? (and after the a has already been parsed) If you have a  
> solution that does not force me to parse all identifiers myself, I  
> am very curious to hear about it.

No, I don't have a solution that would work with a readertable.  I  
should have mentioned that my reader peeked ahead to see if the next  
datum was a dot.

> ----- Original Message ----- From: "Robert Nikander"  
> <nikander at nc.rr.com>
>> I've experimented with writing Scheme interpreters, and I once  
>> added  dot support at the reader level, similar to quote:
>> 'a  --> (quote a)
>> a.b --> (dot a 'b)
>> Different types could implement the dot lookup however they  
>> wanted.   Maybe it's just a slippery slope to syntax hell, or  
>> maybe it's worth  it.  I had to pick another character for  
>> improper lists, but that was  fine with me.

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