Flex and Dynamic Data buffer: Advanced technique

Hi,


This is more advanced problem than simply using yyinput, i need you help.


Is it possible to stop the flex when buffer exhausted and restart
again when more data is available. Flex should restart with previous
state where it left with previous buffer so that it can process
splitted tokens. For example,


Flex is parsing token "Hello"


Initally buffer has 3 byes "Hel", which does not match the token "Hello".
After reading 3 byes, buffer exhausts and hence flex stops.


Now after some time, flex receives more data. Now buffer content is "lo hi"
Flex should restart and be able to detect the token "Hello" which is splitted
between two buffers "Hel" and "lo hi".


I know I can do it with making one more process/thread which waits on pipe
or by other mechanism, unfortunately I can;t use it since this has to be
done by a single process. This process is doing other work also so it cant
simply be in loop to make flex waiting.


I will appreciate you help.


Thanks
Yusuf
[flex parsers expect the parser to call the lexer, and the lexer to call
the I/O, while you want to go the other way around. Either you need to
completely restructure the lexer, or else use a thread package. -John]

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