Question on lex's disambiguating rules

I would like to know if there is any way to override lex's disambiguating
rules, ie:


    "When more than one expression can match the current input, Lex
      chooses as follows:
          1) The longest match is preferred.


          2) Among rules which matched the same number of
                    characters, the rule given first is preferred"


(from M.E. Lesk and E. Schmidt, "Lex - A Lexical Analyzer Generator",
  Computing Science Technical Report 39, Bell Telephone Laboratories,
  Murray Hill, NJ, 1975).


I would like to tell lex to 'commit' to recognizing a
specific regular expression, even though a more general regular
expression should be selected based on rule (1) above.


Specifically, given the following macro definitions:


STRING ([^ \t\n]+)
DIGIT ([0-9])


I have two regular expressions:


{D}{D}":"{D}{D}":"{D}{D} { /* recognize "TIMESTAMP" token */ }


{STRING} { /* recognize STRING token */ }


Because my definition of a "STRING" is so general, the following input
stream:


      12:30:49AC


is tokenized into a single STRING token ("12:30:49AC"), rather than into a
TIMESTAMP token ("12:30:49") and a STRING token ("AC").


Any suggestions on this question would be greatly appreciated.


Jennitta Andrea | Voice : (604) 293-5362
[How about trailing context after a slash? -John]
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