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From: "Jeffrey R. Carter" <spam.not.jrcarter@acm.not.spam.org>
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Subject: Re: lexical ambiguity
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Date: 2006-06-05T22:16:06+00:00
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Frank J. Lhota wrote:
> 
> Well, there is a good reason to consider this worst case scenario. I 
> have seen quick and dirty Ada lexers that try to determine if a single 
> quote starts a character literal by looking ahead 2 character. As this 
> scenario shows, this approach is not guaranteed to work.

That's too simple minded. A character literal can't follow an 
identifier, so this must be either an attribute or a qualified 
expression (presuming it's not an error). Since "(" can't be an 
attribute, it must be a qualified expression. I'm not sure how to parse 
"...", though.

You still have an evil mind, since you didn't include any spaces between 
the components of the aggregate, making it even harder for humans to 
parse (lack of spaces shouldn't make any difference to machine parsing).

-- 
Jeff Carter
"Nobody expects the Spanish Inquisition!"
Monty Python's Flying Circus
22