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480: Mainline 
 

Now, you know how to extract strings from a file and how to test 
particular characters.  Next, you need to learn how to read information 
from the appropriate strings.


The simplest way to read information from a string is to   covert it 
into a stream.  Then, you can extract information from it using 
nextWord—the same method that you used before to extract information 
from a file stream.


In the following fragment, for example, the value of the variable, 
stream, is a stream that you produce by sending asStream 
to a string.  With stream's value established, you can use messages 
similar to those used in Segment 456 to extract the 
information needed to create a Food instance and to add that 
instance to a collection assigned to collection:

stream := string asStream. 
stream nextWord. 
collection add:  
  (Food new name: stream nextWord; 
    fCalories: stream nextWord asInteger; 
    cCalories: stream nextWord asInteger; 
    pCalories: stream nextWord asInteger. 




The fragment skips over the type code and ignores everything in the string 
after the protein-calories number.