READWORD
RW

	reads a line from the read stream and outputs that line as a word.
	The output is a single word even if the line contains spaces,
	brackets, etc.  If the read stream is a file, and the end of file is
	reached, READWORD outputs the empty list (not the empty word).
	READWORD processes backslash, vertical bar, and tilde characters in
	the read stream.  In the case of a tilde used for line continuation,
	the output word DOES include the tilde and the newline characters, so
	that the user program can tell exactly what the user entered.
	Vertical bars in the line are also preserved in the output.
	Backslash characters are not preserved in the output.