书中带的源程序

				The program:
				
				     use-query-handle
				
				takes an argument that specifies the file to read.  It also
				reads the standard input iterating with the user for words 
				to find in the file.  
				The file 'data/Alice_story' is the simple story used for queries
				presented in the book
				
				The program:
				
				     swap
				
				reads a pair of integers from the standard input.  The file
				'data/swap' can be used with this program.
				
				The remaining programs are self-contained. 
				They write to the standard input but do no input.