Reader Examples
foo -> bar means the reader
returns bar when it reads 
the char sequence "foo"
Use FRED c-x-c-r to see what a text region reads to.
See Common Lisp the Language, Chapter 22 for details.
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foo -> FOO  ;creates a symbol with print name "FOO"
b\ar -> BaR ;creates a symbol, does not upper case the char following \
a|bc|d -> AbcD ; creates a symbol. Does not upper case chars between 
                 vertcal bars
2/3 -> the ratio two thirds.
"ab" -> "ab" ;creates a string which characters a and b
(a) -> (A)  ;creates a list with element A
(a . b) -> (CONS A B) 
'foo -> (QUOTE foo)
`foo ->  (QUOTE foo) ;called "BACKQUOTE". In this use, same as QUOTE
`(,a b) -> (LIST A (QUOTE B))  ; A will get evaled by eval, but B won't
`(,@c d) -> (APPEND C (QUOTE (D))) ; assumes that C evals to a list,
             each element of which will appear in the list whose last 
             element is D.
         Ex: (setq c '(1 2))  then `(,@c d) evals to (1 2 D)
; junk  -> comment ; everything between semicolon and newline is a comment 
#| junk |# -> comment ;everything between the delimiters is a comment
#1=(#1#) -> a list which has as itself as its only member. 
        DANGEROUS! Printing a circular list may never finish.
#'foo -> (function foo) ;use instead of 'foo when passing a function as an arg.  
#(a b) -> creates a simple vector with the elements A and B.
#*101  -> creates a bit vector with bit elements 1, 0, and 1.
#,(+ 2 3) -> 5 ; evaluates the form after comma at read and load time.
#.(+ 2 3) -> 5 ;  evaluates the form after comma at read and compile time.
#+foo a -> A if the symbol FOO is in the *features* list, else ignore.         
#-foo a -> A if the symbol FOO is NOT in the *features* list, else ignore. 
#:foo -> FOO ; creates a symbol with print name "FOO" but does not intern it.
#<foo   -> Errors by design. ;use for printed representations which can't be
         read back in.
#\a         -> the character a .
#\A         -> the character A .
#\return    -> the RETURN character 
Use "Char Set" item under the Help menu for other character names.

#b101 -> 5    ;treats 101 as a binary number
#o101  -> 65  ;treats 101 as an octal number
#x101  -> 257 ;treats 101 as a hexidecimal number
#3r101 -> 10  ;treats 101 as a base 3 number. 
#c(1 2) -> complex number with real part 1 and imaginary part 2

#2a((0 1 2) (10 11 12)) -> a 2-d array with 3 elements in each array
               initialized to the [non-evaled] elements in the lists.
#s(ship x 1 y (+ 2 3)) -> a structure of class SHIP with slot x initialized to 1
                    and slot y initialized to 5. Slot values should not depend
                    on lexical variables. 
                    SHIP must have been previously defstructed.


