[pro] Reader macro definition in CLHS

[Pascal J. Bourguignon]

Kazimir Majorinc <kazimir at chem.pmf.hr>
writes:

> -------------------
> reader macro n. 1. a textual notation introduced by dispatch on one or
> two characters that defines special-purpose syntax for use by the Lisp
> reader, and that is implemented by a reader macro function. See Section
> 2.2 (Reader Algorithm). 2. the character or characters that introduce a
> reader macro[1]; that is, a macro character or the conceptual pairing of
> a dispatching macro character and the character that follows it. (A
> reader macro is not a kind of macro.)
> -------------------
>
> I do not understand item 1. In code
>
> ...
> (set-macro-character #\G (lambda(s c) 9.81))
> (setf s (* (/ G 2) (* tt tt)))
>
> #\G is the reader-macro in a sense 2. What is the reader-macro in
> a sense 1.?

G

When you write (/ G D), G is a reader macro, D is a symbol.

-- 
__Pascal Bourguignon__                     http://www.informatimago.com/
A bad day in () is better than a good day in {}.