:white-space

Type:	-	keyword
Source:	-	xlread.c

Syntax

 :white-space

Description

The ':white-space' keyword is an entry that is used in the *readtable* 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

;; define a function to look in a table
;; and print out any white-space characters

(defun look-at (table)
  (dotimes (ch 127)
    (prog ((entry (aref table ch)))
      (case entry
        (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.

See the :white-space keyword in the XLISP 2.0 manual.

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