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:white-space

:white-space

type: keyword
location: built-in
source file: xlread.c
Common LISP compatible: no
supported on: all machines

SYNTAX

:white-space

DESCRIPTION

:WHITE-SPACE is an entry that is used in the *READTABLE*. *READTABLE* is a system variable that contains XLISP's data structures relating to the processing of characters from the user (or files) and read-macro expansions. The existance of the :WHITE-SPACE keyword means that the specified character may be skipped over. The system defines that tab, space, return and line-feed are :WHITE-SPACE characters.

EXAMPLES

(defun look-at (table)                  ; define a function to 
 (dotimes (ch 127)                      ;   look in a table
  (prog ( (entry (aref table ch)) )     ;   and print out any     
    (case entry                         ;   entries with a function
      (NIL          NIL)                ;
      (:CONSTITUENT NIL)                ;
      (:WHITE-SPACE (print ch))         ;
      (T            NIL))))             ;
 (terpri))                              ;
(look-at *readtable*)                   ;  prints  9            tab
                                        ;          10           newline
                                        ;          12           formfeed
                                        ;          13           return
                                        ;          32           space

CAUTION: If you experiment with *READTABLE*, it is useful to save the old value in a variable, so that you can restore the system state.


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