Showing Revision 2 created 05/25/2016 by Udacity Robot.

1. Title:
   Rule Order - Programming Languages
2. Description:

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   As we saw in that last quiz,
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   it's not quite clear what to do when our token definitions overlap.
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   The 7-character sequence "hello"
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   matches our regular expression for word
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   but also matches our regular expression for string.
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   This is a problem not just with computer languages
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   but also with natural languages.
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    As the hypothetical owner of this restaurant would notice,
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    we don't just serve hamburgers, we serve people
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    could be interpreted the wrong way.
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    Presumably those hamburgers are soylent green flavored.
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    We want to have definitive rules for figuring out
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    which of these we prefer.
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    In fact, we're going to use a very simple rule.
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    The first one you list wins,
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    the one closer to the top of the file,
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    so this is our big winner and is going to take priority over string.
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    If you're making a lexical analyzer for HTML or JavaScript,
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    ordering your token definitions is of prime importance.
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    Let's investigate this issue in the form of a quiz.
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    Suppose we have the input string hello, "world,"
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    and we really want that to yield word,
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    the word hello, followed by a string.
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    I'm going to list 3 rules for you,
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    and I want you to tell me which one has to come last
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    for us to get the desired effect.
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    And here, because you've seen it all before, I'm eliding some of the details
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    like the colon, token, blah, blah, blah.
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    Instead what I'd like you to do is tell me
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    which one of these functions, which one of these rules,
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    would have to come last, bearing in mind that the one that comes first
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    wins all ties in order for hello, "world" to break down into
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    a word followed by a string.