Re: Wow, Lisp Reader !!

OMG!! Guys! This is fabulous !!! Thanks to Pascal for enlightening the way forward. And after a little careful work regarding when and which readtable is in place, I now have a wonderful REPL - even better than Forth ever was!

I not only have sexagisimal number input, but I also have C-like syntax 0x100, 0b1_0000_0000, and complex numbers like 1+2j, and dates like 2026/05/24, and arbitrary numbers with #\_ spacers 3.141_592_6 

This is a dream come true!! I cannot imagine moving to any other language than Lisp.

> On May 24, 2026, at 08:14, Tim Bradshaw (as tfb at cley dot com) <[email protected]> wrote:
> 
> I think it definitely is the case that the CL reader is not as general-purpose as some parts of the spec might lead you to think: it's really good for things which are pretty like CL's standard syntax with may be some special additions.
> 
>> On 24 May 2026, at 15:51, David McClain <[email protected]> wrote:
>> 
>> Wow!! You guys have been wonderful and amazing with all your suggestions. I see that I have been too limited in my approaches. 
>> 
>> I’m really glad I spoke up. Even after 30 years of Lisp experience there is still so much to learn. Pascal, I admire the code you sent along for parsing angles!
>> 
>> Now here’s the next challenge - can you do a Vulcan mind meld on the user, from the reader, to ascertain Right Ascension from Declination? Hours are stated as 1/15 of Degrees, so 12 hours is the same as 180 degrees. But they appear the same with sexigisimal syntax, 12:00 versus 180:00.
>> 
>> 
>> 
>>> On May 24, 2026, at 07:40, Tim Bradshaw <[email protected]> wrote:
>>> 
>>> (defvar *rt* (copy-readtable nil))
>>> 
>>> (set-macro-character
>>> #\'
>>> (get-macro-character #\' *readtable*)
>>> t *rt*)
>>> 
>>> Now
>>> 
>>> ? (setf *readtable* *rt*)
>>> #<readtable 8170521CF3>
>>> 
>>> ? 'foo'bar'bang
>>> foo\'bar\'bang
>>> 
>>> Same for the others.  You just need to make the read-macros be nonterminating.
>>> 
>>