[Flex-help] question about using flex to construct a pattern recognizor

[Mengjun X. <mjx...@gm...>]

Hello,

I find flex is a great tool and I want to use it to construct a pattern
recognizor. Please note that the "patterns" here may overlap with each
other. For example, I define the following three patterns

abandon      P1
band            P2
donkey         P3

and I hope the recognizor can find all patterns. For the following line

"whatabandonkey"

My expected output is P2P1P3. I.e.,

"whatabandonkey"
                 ^             P2
                     ^         P1
                          ^    P3
^ stands for the cursor of scanner.

However, due to the use of left longest match, Flex only outputs P1 instead
of P2P1P3. I am thinking if there is a way to achieve this by modifying the
source code of flex (if there is an easier way, please tell me). I look at
the code a little bit but it is too complex to get to the point in a short
time. So could you guys give me some help on this! Thanks a million!

Mike